Phil's Blog:

This is a page to list current developments, new projects, anything that crops up...

Its been a while. We've been in lockdown for nearly 6 weeks now and project work has been a welcome distraction.
Over recent months its become harder to find R/C modules such as the Frsky DHT and OrangeRx DIY as manufacturers
cease production. Meanwhile theres a variety of cheap non-R/C tranceiver chips on the market, so with this
in mind I had a go at a cheap-as-chips R/C outfit using the NRF24L01 which is plentiful and costs about a pound.
Initially it worked over a single RF channel in the 2.4ghz band, became a hybrid six-frequency hopping set, then
developed into full Frequency Hopping Spread Spectrum (FHSS).
The hybrid transmits the same data across six channels in turn, rather like Spectrum DMS2 transmitting on two
channels, and the receiver only hopped if it started to lose packets on the current channel. My thinking was,
if you're receiving good data, why hop? Well this system works great and we've been racing model cars with it
with no problems whatsoever - but for interests sake I wanted to go to full FHSS.

The FHSS set uses sixteen RF channels within the 2.4ghz band, stepping through these channels once every 5ms.
Software ensures that the receiver keeps in sync as it follows suit through the hopping scheme, even through
batches of lost packets. It works really well and a couple of mode-zero members have tried it too.

Here's an early prototype, in its pre-FHSS phase:

The full story is here: Phil's lockdown project - a 4ch propo NRF24 set
...and here: Frequency hopping experiments on the NRF24

I've been making receivers from separate NRF24L01's and Prominis, but recently I found the RF-Nano which is ideal,
just add servo connections, either a block like this or individual servo leads:

Here's the hybrid set on Martins 2.4 spectrum analyser:

Here's the prototype in action, excuse Dave's driving as steering and throttle were on a single-stick:

This is really for my own satisfaction, I've wanted to revisit the 7 channel encoder project for ages but
its only recently that I've found the incentive to get it done :-)
It has some nice features over the original, and the code is prettier, which is important - I always
felt that the original had a smack of "My First Arduino" about it :-)
Although I dont expect much interest in the new version, that doesnt bother me at all as the object was
purely for me to be happy with the project, and if anyone else fancies trying it, thats great, its a bonus!
The new code works great, with some nice new features, and hopefully there wont be any more changes!

Here are a few details:

Interrupt-driven PPM (same as the Reeduino) replaces the inline timed method
S/C escapement emulation has the option of a faster rotation speed (for Pete C)
Minute-minder flight timer (for Scott)
Channel 7 servo-slow speed option (for Paul J)
Switchable channel order Fut/Spek/Spek400uS/ETAR (ETAR is for modules with an unwanted map)
When TAER-gear-aux1-aux2 is selected the PPM changes to 400uS pulses to suit Spektrum DM8/DM9 (for Dave R!)
Expo now mimics Futaba expo (thanks Mike & BEB), buzzer moved to D13 (with the onboard led)
Channels changed to 1100 - 1900 plus trims, ie trims now excluded from calibration
3-position calibration mapping to ensure neutrals with imperfect sticks

The channel-order selection makes it easier for me - I dont have to set AETR or TAER on requested boards.

Old stuff retained:

Reversing by holding stick over on power-up, V-tail 50:50 mixer, Elevon 75:25 mixer
Two throttle locks, one hardware switch and the soft-lock
S/C mix (now 2-speed), slow ch7 now with 2 speeds and retaining the single-handed range-test sweep
Inactivity alarm, etc etc

At the Buckminster Retrofest I was asked by Doug Hunt of the BMFA FF Scale committee if I could come
up with something to solve a problem they had with electric FF scale models. For safety and imminent regulatory
reasons they need to be able to cut the motor or motors remotely to prevent flyaways and to down a model thats
heading for the spectator line.
Electric FF models generally use a conventional ESC controlled by a 'profiler' which allows the power delivery
to be preset in 'phases' before the flight. Electronic-music buffs will recognise this function as an 'envelope generator'.
There may 3 or more 'phases' - ramp up to launch speed, climbout, cruise, ramp down to avoid a stall, and finally cutoff.
The problem is that the cut-off phase is unaware of any circumstances that might warrant panic-mode!
I've sent a few prototypes to Doug - its just a PIC12F675 with 3 cables for the ESC, Profiler & R/C receiver.
They will be assembled dead-bug-style on the underside of the chip, which keeps the size & weight as low as possible.

Here's my oversized test board, nothing much to it - very simple but does the job perfectly. Essentially a switched R/C
channel (flaps, retracts etc) enables or disables the ESC. Actual cut-offs will be much smaller of course:

Based on the 4ch DigiSpark encoder I've done a 3ch version which doesnt use P5 and therefore doesnt need
the fuse programmer - so its an easier build for rudder/elevator/throttle sport or vintage models.
Other than dropping a channel, it has all the facilities of the 4ch:

Three proportional channels, inbuilt stick calibration,
'Soft' throttle lock (has to be closed before it will open),
Reversing by powering on with the stick held over, saved to flash (throttle is not reversible for safety),
V-tail or Elevon mixer (60:40 ratio),
Single Channel compound escapement emulation mix with kick-up elevator,
Inactivity alarm (should you forget & leave it switched on).

Here's my EK Logictrol 3 ready for a trip to its first trip to the flying field in 50 years!

I've done a full 4-channel proportional encoder for the DigiSpark, this is a cheap, dependable 3/4" square processor.
Here's a list of its features ( a short list, but when you've only 6 pins to play with...)

Four proportional channels, inbuilt stick calibration,
'Soft' throttle lock (has to be closed before it will open),
Reversing by powering on with the stick held over, saved to flash (throttle is not reversible for safety),
V-tail or Elevon mixer (60:40 ratio),
Single Channel compound escapement emulation mix with kick-up elevator,
Inactivity alarm (should you forget & leave it switched on).

As we need all the DigiSparks I/O, the project makes use of the fuse-programmer described below

Looking into the back of the Digiace, the 35mhz RF module is top left and the tiny white DigiSpark encoder top right.

One of the advantages of the old 8-pin PIC chips was that other than pos & neg, all six remaining pins
were available for I/O. This isnt the case for the Atmel ATTiny chips: as supplied the DigiSpark has five
I/O pins, as does the bare ATTiny85 on which its based. The sixth terminal, P5 on the DigiSpark board and
pin 1 on the Attiny85 chip is the 'Reset' pin used by the programmer.

In fact this pin has two functions, it can be 'Reset' or it can be another I/O pin, with
interrupt, analogue and digital modes, and can be configured with 'pullup' just like any other pin.
In a nutshell, to program the board P5 must be configured as a Reset pin, and this is how its supplied
by default. To use P5 as I/O just like any other pin, it has to be set to I/O. This setting is determined by
one single bit of the high-fuse. To change any of the fuses requires a special high-voltage programmer, which
few people have access to - so here's a project specifically designed to flip the DigiSpark P5 between RST and I/O.
For DigiSpark users, the only hfuse values of interest for this purpose are DF which means P5 is a reset pin,
and 5F which means its I/O.

Whilst the fuse-programming routines are by Paul Willoughby and Jeff Keyzer, I've condensed the project into a
small hand-held, stand-alone device and added an OLED display. Being stand-alone means its self-contained,
you dont need to plug it into your PC.

Here's the prototype in action:

The full story is here: DigiSpark with 6 input/output pins, homebrew fuse-programmer

The PIC Galloping-Ghost Recoder has been a very popular project and was adopted by Tobe for his re-engineered
'Rand' clone actuator. There are a few GG demo videos on my Youtube channel - PHILG2864 featuring
Galloping Ghost models by David Lovegrove, Shaun, Jay Mendoza, Otto Diefenback and more. Whilst the PIC recoder is
easy to build, few are equipped to blow their own PICs, and so it was never a 100% DIY project.
For this reason I've replicated the PIC Recoder on a DigiSpark PCB, which is a very small and cheap Arduino-compatible board.
Its larger than the PIC recoder but this makes it a much easier DIY proposition and much easier on the eyes

Here's the prototype in action:

The full story is here: GG Recoder for DigiSpark ATTiny85 and DRV8838

Sorry I've not been keeping this up to date but the projects have continued but I forget to post them.
The Digimac 1+1 emulation encoder based on the Digispark board has been updated again, it now has
auto stick-calibration, electronic rudder trim, throttle & trim pips, presettable mid-throttle
(mid-throttle no longer has to be exactly half, you can now set it anywhere between low and high)
throttle LED with 'next speed' indication (like the S/C encoder), inactivity warning so you dont leave
it switched on... this is a really popular project, I supply the encoder prewired so a conversion is
very easy - just theres just the battery, module, button and stick to connect:

There's also a new 2+1 encoder specifically designed for a small, cheap stick unit I found on ebay:

This stick is nice & sturdy, but doesnt have mechanical trims and doesnt centre absolutely accurately,
hence the specific 2+1 encoder for it which has a presettable 'dead-band' to keep servo neutrals spot-on,
and sub-trims by holding the stick in the required direction and dabbing the throttle button.

Also for the DigiSpark board (you'll have gathered, I love this tiny little board...) I did a V-tail mixer,
old-hat and probably obsolete I know, but it was just an exercise and works very well.

All three of these projects can be found on the Archive page.

Away from the usual R/C stuff I've done an aero-tow 'winch layerer' for a Swiss glider group, and theres been a bit of interest
in the old 'servo memory' project:

Just finished an updated Digimac 1+1 emulation encoder based on the Digispark board. Has many advantages over
the old PIC 1+1 encoder, such as auto stick-calibration, electronic rudder trim, throttle pips,
throttle LED (like the S/C encoder), AND its significantly cheaper!
Will do a video asap

Here's an Alexa-controlled servo driver. It could be used for anything where a simple movement is needed - close the blinds,
bolt the door, kick the cat, prod the dog...

All these projects rely on Kakopappa's excellent code which emulates a commercial Belkin Wemo switch.
He snooped the traffic between a real Wemo and Alexa, and by recreating the appropriate responses with
clever code, he has managed to convince Alexa that she's controlling a Wemo switch.

The only drawback of this approach is the fixed dialogue - "Alexa, turn XYZ off" and "Alexa, turn XYZ on".
It would be nice to say "Alexa, slowly move the servo to 65 degrees" but that involves a whole new world
of 'Skills' programming so for now we're stuck with things you can achieve with just 'on' and 'off'.
You can use sequences of course - say if you said "Alexa, turn XYZ on" (or off) twice in succession,
she could centre the servo. But most operations are two-state, the door is bolted (or it isnt),
the blinds are shut (or they're not), the cat is kicked (or is not available for comment...)

I've placed the servo and its wifi controller near to Alexa just to get everything in shot, of course when Alexa
talks to the controller its not directly, but via your router, so the servo & controller can be anywhere within wifi
range of your router or any connected access point. The kennels network (you remember we're a boarding kennels?)
is quite extensive, remote video servers etc, but its all layer 2 and the default gateway for everything is my own router.
This means the servo can connect to any of our many wifi access points around the premises - in reception,
in any of the kennel blocks, in my garage, outside at the main gate... quite a distance from Alexa.

By the way, are there any Sci-Fi fans here who enjoy "The Hundred" on TV?
We've deviated a long, long way from Kass Morgan's books haven't we?
Well, I imagine Alexa to look like Ali the 'evil' AI who (it transpires) actually had our best interests at heart

I bought the Amazon Echo as a package deal with the Harmony Hub, which is supposed to be a bridge between
Alexa and any infra-red remote-controlled devices. However, in the UK we are not permitted the full
home automation skill, making the Harmony/Echo combination virtually useless and a huge disappointment.

Continuing the "start simple and work up" theory, I've made a homebrew 'Alexa' controlled TV remote,
and it actually works more reliably than the 99 Harmony Hub :-)

"Alexa, turn the telly on"
. . . . . . . . . . . . . . . . . . . . . . . "Alexa, turn the telly off" :-)

Exactly like the power-switches, it uses a modified 'ESP8266 Relay' board from Aliexpress as mentioned above,
and a variation of Kakopappa's Wemo code, modified to give momentary responses, simulating a keypress on the TV remote.

As standard, the Aliexpress Relay board has a secondary (STC) processor which decodes serial commands from the ESP-01
into the relay on/off signal. I couldnt readily find the serial command format but I did find a schematic, and being impatient
for results, opted to modify the relay board so the ESP-01S controls the relay via a simple high/low on GP2, which is an
otherwise unused digital output pin.

Here's the relay board as supplied by Aliexpress, it includes the ESP01 (the little daughter-board with the wiggly aerial)
yet costs only three and a half quid! The screw-terminals are for power in (5v) and the relay make, break & common contacts.
As you can see its quite a substantial relay:

...and here's the link:
The hardware mods are easy to do and involve adding a couple of 1k pull-ups on GP0 and GP2, removing an SMT resistor,
and connecting a 10k resistor from ESP-01S GP2 to the old resistor pad. The same mods apply for a power switch or
the TV remote.

First the tiny SMT resistor R3 is removed, to disconnect the STC chip from the relay driver:

A 10k (or 4k7 etc) resistor connects the R3 pad nearest the edge of the board, to GP2 on the ESP01:

Its probably not necessary but I didnt like the idea of the STC processor putting 5v signals on the ESP01
tx & rx pins, so cut the two lands. Finally, 1k pull-ups are added to GP0 and GP2.
The pull-ups are key to the reliable operation of the wifi module, thats what caught me out earlier on.
All part of the learning process eh. I used an SMT for GP0 (the tiny diagonal component):

Despite the 80mhz clock I was unable to get 38khz PWM working on the ESP-01S and so settled on a cheap
universal remote from ebay - quicker, cheaper and easier!

Here's a video of the working remote (albeit a lash-up at the time!):

Total cost of all components, about 5. As you can see it was temporarily running from an R/C receiver battery pack.
Since the video was made it now runs on a cheap 5v USB power supply so its always on. It still needs a nice project box
to house it, maybe a neat round one to fit under the Echo unit. The IR unit obviously needs to point at the TV without
obstructions, although IR seems to bounce off a white ceiling quite well.

I've also done an Alexa-controlled servo driver, so she could operate say a door-bolt or whatever.
I'll write the servo thing up later if anyones still following this.

As a SciFi fan I've always liked the idea of talking rather than typing to a computer, and the possibility
of voice control over lighting and simple appliances. Talkie-Toaster from Red Dwarf was one of my favourites!
Ultimately I couldnt resist the reduced-price Amazon Echo in its 'Dot' format, and I've been experimenting with
homebrew add-ons for the Echo. "Start simple and work up" was the theory, but there is so much you need to learn,
from datasheets and manufacturers specs, even to voice-control a simple light-switch!
I've been using the ESP8266 system-on-a-chip which combines an Arduino-like processor with WiFi connectivity.
There are many caveats and gotchas with the ESP8266, much trialling and even more erroring, and to cut a long
story short I can at last ask Alexa to turn an LED on or off! This might sound very very trivial, but in fact
thats all the hard work done, and interfacing a solid-state-relay to the LED is a piece of cake!
Here's a demo of this humble achievement - listen for Alexa acknowledging each request with "ok" (she's very polite!):

This morning Postie brought me my new Frsky Hall-Effect gimbal, I've been waiting a while for UK stock.
I ordered one just for curiosity and a possible project (I no longer have a Taranis).
Connected it to an ebay red board running the 7ch+S/Cmix, recalibrated and gave it a whirl - and it is quite superb.
The centring and linearity is spot on and it feels silky smooth, as it should with no pots!
Theres loads of scope for adjustment of tension, and friction or ratchet.

Beware its a 3v3 device though, dont forget and plug it into a 5v header. I used the Nano 3v3 output for the test.

The output is almost rail-to-rail so resolution is much better than a partial-travel pot, and if you use a 3v3 adc
reference it will be 'true' 1024 resolution with say a 328P or pic's 10 bit adc.

Depth-wise its very shallow (slightly over 1") so will fit in a nice slim case, & it sits in a 48mm diameter cutout.
I intend to remove the four raised bolt mounts to make it sit flush against the inside of a flat case.
There are no trims of course but we knew that didnt we.

They're not cheap, about 20 here in the UK, but I think good value for a quality product. Mine came from T9:
T9 Hobbysport


The latest project was simple but fascinating. Francois lives in Belgium and works with birds of prey.
He trains his Falcons using airborne lures which are dropped from height, and which the Falcons catch in mid-air.
Presently the technique is to use a kite to take each lure up, one at a time, which means he has to lower the kite
every time to reload. Francois had seen the RDT articles in Aeromodeller and thought it was almost what he was
looking for, and after discussing various ways & means we settled on a simple miniature transmitter with four lure release
buttons. Having several 'shots' per flight this gives more options to tailor the exercises to the falcon's progress.
He's going to use an Orange RF module and a lightweight Lemon receiver, much as the free-flight boys have with RDT.
Though simple in design, this has been a fascinating exchange and I'm hoping Francois will send a couple of
photos over when he tries the system in practise.

Another Reeduino update. Previously the single-channel emulation servo deflections were fixed, now they move
relative to the rudder (& elevator) ATV settings. This means that if you use ATV to reduce the maximum 'reeds' rudder movement,
the S/C movement reduces accordingly, conversely if you increase the reeds throw with ATV, the S/C throw increases proportionately.
This affects both sequential and compound modes, based on rudder ATV for sequential and rudder & elevator ATV for compound.
I've played with it and its better, its a good change.

I've done a Reeduino demo on Youtube:

More on the Reeduino:
I've added the option of a Tiny6-style trim-button which will be familiar to anyone presently using a Tiny6.
Its an option, without any code changes you have the choice of either the realistic reeds trim toggle, OR the Tiny6 trim button,
whichever you prefer. (actually you could have both but thats totally unnecessary! ...)

The button is just a hardware option and can be omitted if you dont want it and prefer the authentic up/down toggle, but it does
simplify a basic Rudder/Elevator/Throttle 6-channel reed set as you no longer need an extra toggle for the elevator trim.

If you're building a full-house set, for authenticity I'd suggest fitting all the toggles (omitting 'aux' for a 10-channel set).
Dont fit the trim button, and nothing has changed - its the familiar full-house reeds layout.

If however you're building a simple 6 channel RET set, I'd use the button rather than have another toggle switch which would spoil
the appearance of a 6-channel set, as traditionally they would have only three toggles. If you do omit the trim toggle, set it as
inactive in the 'activetoggles[]' array - ie the last entry in activetoggles[] will be a zero. There are examples in the header -
eg a Tiny6 clone would use {1,1,0,1,0,0} for three toggles, aileron, elevator & throttle. These three toggles would physically
connect to A0, A1 & A3 respectively: (aileron is your primary steering channel in a RET configuration)

// Configuration section: // indicate which toggles are wired up, 0 for no, 1 for yes in the order: aileron, elevator, rudder, throttle, aux, trim
const bool activetoggles[] = {1, 1, 0, 1, 0, 0}; // 1 for the toggles you are using, 0 for unused ones, this prevents unwired ones reading randomly

The trim button can be quite discreet, as on my own RCS Inter-6: (between the RCS logo and the 'Inter 6' decal)

Its only a small change but worthwhile I think if you're building anything less than a full-house reeds set. Its just an either/or option.
Personally, 6-channel reeds is my favourite mode, and with this update we have the option of a Tiny-6 clone with ATV & S/C emulation.
As usual the sketch, updated diagram and the document are on the Archive page of

04/02/2017: Some feature additions to the Reeds emulation encoder for the Arduino, details in the entry below:

11/01/2017: I've done a Reeds emulation encoder for the Arduino, for ebay red boards or 328P boards etc,
it was originally intended to exactly mimic the PIC reeds encoder, which it does perfectly, but
I've also added the Single-Channel escapement emulation mix, a V-tail mix, and Adjustable Travel Volume too.
It does any even number of reeds channels up to 12, with variable transit speed, trims throughout, reversing, rangecheck, etc...
but if you prefer, you can ignore the extensions and use it just like the existing PIC 12-channel reeds encoder.
My thanks to TipTipFlyer for doing the flight tests and contributing a few suggestions
Video to follow, meanwhile the sketch is [P18] on the Archive page.

27/10/2016: Just a quickie as this will only concern retro converters with pre-mixer sets.
Of course on-board mixers are old hat now but Ron wanted to fly his "Little V" on reeds.
Ron is a Frsky user and tried commercial mixers and homebrews but couldnt find an on-board mixer
that worked properly with his receiver, a D8R.
The reason is that some receivers, including the Frsky D8R, output the servo signals simultaneously
rather than in sequence as is the norm. This confuses a conventional V-tail mixer which either doesnt
work at all or picks up only every alternate channel pulse, which means the servos see only 25 updates
per second rather than 50, and this causes stuttering and latency especially when most commercial
mixers are only 10uS resolution.
Anyway, purely for this type of receiver I've done a new mixer specifically for simultaneous inputs.
It has one uS resolution.
These two traces show the difference between a V8FR and a D8R, both on channels 1 & 2:

V8FR, conventionally sequenced channels:
D8R, simultaneous channel outputs:

I realise its unlikely but if anyone has a retro transmitter without a built-in mixer, and
also has a simultaneous-output receiver... if you want to make a mixer... just saying... its here :-)

20/09/2016: Aeromodeller magazine have published a feature on the remote de-thermalizer trip (RDT) encoder,
following which I've had quite a few more requests. Apparently RDT is becoming an essential feature
at some flying sites, especially those owned by the MOD. And still the CAA do not permit
GPS fencing in free-flight models. Crazy!

10/01/2016: The remote de-thermalizer trips (RDT) seem very popular at the moment, I've settled on a hardware format using
the tiny ICP07 SMT board (as used in the Tiny-6 reeds encoder) and the simplest of software to literally just trip
the DT and nothing else. A dozen or so have gone out this month, so free-flight must still be popular!

15/09/2015:Sorry I've not been keeping this up to date lately.
I've just built one of Martin Round's Arduino-based S/C encoders, the development of this fascinating project can be followed
here. Martin has taken a somewhat different approach to my own, with an LCD display for setting up all the parameters,
to which he has also added telemetry! Rather than the usual rats-nest I did an all-on-one PCB:

...its not cased yet (trip to Maplin required) but should be flying soon.

10/07/2015:For a while now I've been doing these channel-6 adapters for the Spektrum DX5e & DX4e.
Channel 6 is normally a sprung-return toggle, in fact its the 'trainer' switch. This limits its use, so I've made a range
of modules to make channel 6 more versatile:

...this led to to an idea for DX5e (and DX4e) users who might like to try Single-Channel using their existing kit!

30/01/2015: This project was just me having a bit of fun, I set myself a one-evening project as a challenge using only stuff I had to hand.
I wanted to make a tiny 2 channel set for my small rudder-elevator models, but it had to be full-range and usable.
The module is an uncased Frsky V8HT with the bind board removed, the encoder is pic assembler on an iCP07 board (smt pic12f675),
battery is a 2S Life PP3 and the gimbal is a PlayStation type from ebay. The whole thing is smaller than my s/c OS Pixie!
...and it was finished just before midnight so passed the 'one evening challenge' !!!

I've since modified it to give a sequential throttle by pressing in the joystick:

26/11/2014:After varying success with my Dad's home-brew S/C radios, the OS Pixie was our first ever commercial R/C set.
It was supremely reliable and I've many happy memories of single-channel slope soaring back in the late 1960s.
Consequently I was really chuffed to find this Pixie tx at the Nats and paid 15 for it. Its far from mint, has cracks and chips
but its just like the one we had. Its fully converted to modern 2.4g spec and has been flown many times very appropriately
in an Irvive Pixie slope glider! Slope soaring a single-channel glider is great fun, even more so than it was 'back in the day'
because of the 100% reliability of modern S/C gear. I really enjoy S/C slope soaring!

28/10/2014:Published the Kraft/Arduino document & sketch - its on the Archive page, docs P16 and P17.

15/10/2014:After what - two years? - of ribbing, I've finally done my prototype Galloping Ghost re-coder, and its working really well!
It accurately recreates the GG mark-space and rate signals for a Rand, Controlaire Ghost or Mighty-Midget GG actuator,
and is controlled by any conventional R/C set using the rudder (or aileron) and elevator channels. It doesnt do the GG throttle.
Here's a demo video of the earliest prototype (with huge 60 amp mosfets for the bridge!):

I've been experimenting with different bridge circuits, with a view to reducing complexity, size and weight.
The Mk2 used an L293 16-pin chip and works fine but I've since used an 8-pin DIL bridge which will make the end product
look exactly like the pulse-propo adapter - just a blob on a servo lead!
I'll post an update when the final version is done, (it needs neatening up)

15/08/2014:The Kraft Series 71 refit is finished, I cant think of anything more I would like to add to it.
Here's an updated video:

The updated spec is:
7 channels, 6 propo, one toggle switched (ch7) with built-in servo-slow,
Self-calibrating sticks, saved to EEPROM during power-off - no measurements or presets (uses mechanical trim stick units)
Servo-reversing by holding sticks over on power-up, saved to EEPROM during power-off (throttle deliberately doesnt reverse, its a safety thing!)
Rates variable from 100% down to 10% via a pot, click for no rates
Expo variable from none to lots via a pot , click for no expo (sincere thanks to Paul Luby for his expo maths!)
Single-handed range check mode, flick the ch7 toggle three times to invoke, throttle is held off in range check mode, exit by moving stick
Switchable elevon mixer for flying-wings with option of 75% aileron & 25% elevator or 50% & 50% for V-tails etc
Servo-slow on switched channel 7 (flaps, retracts etc)
Auto throttle lock on power-up. You must close the throttle before opening it.
Switched manual throttle lock which also engages the auto lock, so you cant manually unlock the throttle whilst its set 'high'
Audio warning of throttle high whilst locked
Inactivity timer, audio alarm if controls are not used for 10 minutes (so you dont leave it 'on' and destroy a lipo!)
No bootloader delay, instant ppm so Corona-safe!
True Single-Channel compound escapement emulation!     Fly propo and 'S/C on the button' at will!     Have your cake and eat it!

Here's a demo of the built-in Single-Channel compound escapement emulation:

There are no switches or modes to select S/C operation - the emulation is a 'mix' which is merged into the proportional channels,
and everything happens simultaneously - you can use any combination of the sticks and the button at the same time!

30/07/2014: I've recently refitted a Kraft Series 71 using a Frsky 2way DHT module and a home-grown encoder based
on an Arduino Nano. Its a work-in-progress, but here's a demo video:

The present spec is:
6 channels, 4 propo, one toggle switched (ch6), one momentary pushbutton
Self-calibrating sticks, saved to EEPROM during power-off - no measurements and presets needed (uses mechanical trim stick units)
Servo-reversing by holding sticks over on power-up, saved to EEPROM during power-off (throttle deliberately doesnt reverse, its a safety thing!)
Rates variable from 100% down to 10% via a pot, click for no rates
Expo variable from none to lots via a pot , click for no expo (sincere thanks to Paul Luby for his expo maths!)
Single-handed range check mode, flick the ch6 toggle three times to invoke, throttle is held off in range check mode, exit by moving stick
Switchable elevon mixer for flying-wings with 75% aileron & 25% elevator
Servo-slow on switched channel 6 (flaps, retracts etc)
No bootloader delay, instant ppm so Corona-safe!
True Single-Channel compound escapement emulation!     Fly propo and 'S/C on the button' at will!     Have your cake and eat it!

Here's a demo of the built-in Single-Channel compound escapement emulation:

There are no switches or modes to select S/C operation - the emulation is a 'mix' which is merged into the proportional channels,
and everything happens simultaneously - you can use any combination of the sticks and the button at the same time!

05/05/2014: I just wrecked another lipo by accidentally leaving one of my single channel transmitters switched on
for several days, this is the second time its happened!
So, taking advantage of the situation, I've added an 'inactivity timer' to the S/C encoder.
It works in either compound or sequential mode, and simply sounds an alarm if the tx is switched on and you've
not pressed the button for 10 minutes.
Control continues throughout the alarm, so if your model is so impossibly stable you've actually flown 10 minutes
without steering it !!! nothing untoward happens, just the alarm noise, and that stops on the next button press.
In the real world, more likely if the alarm goes off then like me you've left the tranny switched on and forgotten about it.
This is version 'N' 5/5/2014 and all subsequent S/C encoders will have 'N'.

15/03/2014: Great news! Doug has created a new Forum for retro-R/C enthusiasts:
Please register and post your experiences, be that S/C, GG or reeds flying, your new model, or just reminiscences... !

14/12/2013: Finally had a bit of time to put a prototype 6 channel reeds set together using the new 'Tiny' emulation encoder!

Had just half an hour down the park the other day, took the new 6ch Reeds and the Mpx Cub, did a range check using the
auto-waggle (its a new DFT module) and then had a few short flights. The Cub is hugely overpowered and the combination of big throws,
bang-bang controls and the 'fast' setting for servo-slow transit speed made it quite twitchy until I got used to it again.
But no problems other than overcontrolling, the slower transit speed option is much better, but the Cub also needs more sensible
surface throws!

The button idea for the trims worked great, I like it, it feels natural and pip counting gives you an idea where the trims are.
The mini-toggle switches from RS - I'm not so keen. They work well, excellent quality, nice & positive and good feedback but the
toggle edges are too sharp on your thumbs for comfort. I need to find some slip-on toggle covers.
But all in all, a successful test session!

Features - the new 6 channel 'Tiny' is a true six-channel Reeds Emulation Encoder and has trims on all functions, servo reversing
on all functions, servo slow on all functions with two speed options, and a single-handed range check mode.
All the trim, reversing and transit speed configuration settings are saved to flash and therefore retained during power off.

In flight tests I found the 'high' transit speed a bit 'lively' for my overpowered Cub, the slower speed is much smoother to fly and
is more typical of period reed servos. The slower of the two settings is the same transit speed as I use on my Junior 60 and Tauri.
I've uploaded a draft document to , its right at the bottom
of the Archive page under the QR code.

29/10/2013:The 'Elf' lives! check the '2.4g conversions' page!

24/10/2013:Terry Tippett (of Micron fame) has very kindly donated his old Gallatrol Galloping Ghost set, its just arrived and its very clean for a 45+ year-old set! I'm going to see if I can get it going again with a rand actuator, maybe not to fly but as a demo set:
Also Wiggles has let me have his old Micron 'Elf' s/c propo set - I'd been looking for one of these for ages!
The 'Elf' will be flying again soon, possibly in an Impala s/c glider or the Go-Jet (when I get them finished!)
This has been a very unusual week- we do get occasional donations but three in a week is unprecendented - My lucky week!
The third set is from Phil Greetham who kindly donated his old Macgregor Digimac 1+1 outfit - this is complete with both rudder & throttle servos, wiring harness and switch - unfortunately it doesnt work, so needs some TLC which it will be getting very soon!
Many thanks lads!

17/10/2013: More Single Channel Emulation Encoder PCBs!
Just received my fourth order from the good people at PW Circuits, another 100 this time takes the total to 300 in all!
Three years ago I would never have believed that single-channel flying on the button would appeal to so many!
I'm presently building a 'small as possible' 2-channel propo transmitter for my smaller gliders, and whilst squeezing all the electronics into a tiny case, I had a Eureka moment! Remember the small commercial SMT boards I use for the 'Codamac' coder? These are about an inch square and it occurred to me that I could port the 2+1 encoder software onto one of these little boards! Result!
Went to the Retford Retro event on Sunday, had a great time flying s/c with the lads and their 1970 aerobats, won a bottle of wine on the raffle and came back with a few additions for the Antique R/C presentations! Thank you lads!
The Ponty Single-Channel & Retro R/C event gets a really good write-up in RCMF (Radio Control Model Flyer) magazine this month (Oct) thanks to Bruce Corfe, 5 pages and lots of photos we'd not previously seen - well worth a read!

20/08/2013: Remote Dethermalisers
Purely by coincidence I had two requests within a week for remotely triggering the dethermaliser of a freeflight model via a tiny 2.4g transmitter.
I used the standard emulation encoder hardware and the software to suit the slightly different requirements - John flies only rubber-powered competition models and literally wanted just a DT trip. His had status LEDs, throw adjust and servo reversing.
Gordons also had a motor run channel, which allowed 'test blips'of the motor, but if held on for launch would then stay while the button was pressed. After the required climb time, the button is released to stop the motor, and the next press trips the DT. LEDs show the statu salong the way. Gordon wanted a manual motor run as the rules on remotes in freeflight are not yet fully sorted.

14/06/2013: 3-position Thottle adjustment widget!
This device is an optional add-on for a S/C setup using the emulation encoder, especially the 1+1 and 2+1 which have no configuration options.
It sits onboard, inline between the throttle servo and the throttle channel from the receiver. It provides a servo-slow function and adjustable positions for low, medium and high throttle.
Any of the 3 positions can be anywhere within the servo throw, which includes reversing the throttle by setting 'high' at the low end and 'low' at the high end.
In fact the output is slightly extended - from 800ms to 2200ms to give a little extra throw if this is required.
The purpose of the Throttle Widget is better control of an IC engine throttle - it allows you to precisely set the full and tickover carburettor positions, and to choose a mid setting for 'cruise' flight.
Engines are very non linear in their response to carburettor openings, so half power might be at 25% throttle - the Widget allows you to set the 'mid' position to 25% or anywhere you like. The servo-slow function helps to prevent the engine coughing when the throttle is changed suddenly, by allowing the engine time to respond.
Failsafe - it follows the receiver settings, so if you have failsafe set to low throttle, the Widget will set low throttle on failsafe. If you have failsafe set to 'no pulses' then the Widget will stop pulsing on failsafe. It simply mimics the receiver setting.
This is a veroboard prototype and physically a little larger than I'd hoped, but today is Friday and the
Pontefract PANDAS S/C meeting is on Sunday so time was limited. The planned enhancement will have one external pot, which you plug in to make adjustments, and then remove.
This will make the enhanced Widget much smaller and a bit lighter.

13/02/2013: We have a date for the 2013 S/C meeting at Pontefract - see header on the home page for details!

06/02/2013: The commercial boards I mentioned earlier (22/01/2013) have arrived - I tried the 'coder' software
and they work perfectly, I'm really pleased with them! So I can supply coders again for anyone doing a
Macgregor 'Codamac' conversion or similar. I can see these boards being handy for all sorts of RC projects!

22/01/2013: Not directly related to the 2.4g conversions but maybe of interest, I designed an elevon mixer
for CPPM (ppmsum) receivers such as the Frsky 'D' range. I wasnt happy with the low resolution of commercial mixers
(usually 10uS steps) and I needed one for my Wildthing. Using CPPM means between the mixer and the receiver you
only have one lead which carries all channels, making the installation a bit neater.
I flew the Wildthing & mixer today in a steady, measured 45mph westerly and had a brilliant day!

22/01/2013: A few people are waiting patiently for Coder boards.
This is the tiny board which sits between you and the 'tone' button on a Single Channel set, automagically doing
all the 'one-for-right', 'two-for-left', 'three-for-kick-up-elevator' and 'quick-blip throttle' malarky.
Well, some good news.
I should be in a position to supply ready-made Coder boards again very soon for the Codamac conversions.
Whats happened is that purely by chance I have found an industrial PCB that is electrically almost identical
to my Codamac board - its uncanny, although its just a PIC chip, a 5v regulator, supply protection diode,
and all the I/O connections. So I ordered a dozen to try.
Once the boards arrive I'll port the Codamac software onto it (it will need some translation) then I'll need
to change the document, or rather add the new board to it. It should be really neat as its all SMT.

20/01/2013: Since I flew my 1+1 last there have been a few developments - the resolution is better
than twice as good as it was on the early set, and the pot is easier to set up now and the possibility of
wrap-around has been removed. The previous working version was 16G, this update is version 16I.
I've added a cheat LED on the throttle, red for stop, green for go, alternate red/green flash for half throttle.
The flash rate tells you which setting comes next, just like the S/C encoder - fast flash means fast throttle
comes next, & vice versa.
You can choose to have the LED visible or not, your choice, its just a 3mm hole & some hot glue!
I'll add this to my own 1+1 too as I'm often forgetting which throttle setting comes next, accidentally
landing when I'd planned to pull away...
Please download the Digimac 1+1 document from the Archive page - its number 8, and theres also a document on
setting up stick pots which is number 10. Its a lot easier now I've numbered the documents!
The main thing with all the propo encoders is to set up the neutral correctly - the wiper should be at
about 1.85v with the stick at neutral. To be precise its 3/8 of whatever the 5v regulator is putting out
- usually about 4.85 or 4.9v, which you can measure on the red & black wires to the pot.

19/01/2013: Tonight I did some further work on the 5 channel encoder. The built-in 'servo-slow' on
channel 5 is now a selectable option, or you can have ch5 snap end to end.
I've reluctantly realised that I had to add reversing to the throttle channel, which I'd avoided for
safety reasons. When a recent conversion by chance had physically reversed stick,
it had to be! But, the way you reverse it is different though, its deliberately a bit more involved and
almost impossible to do unintentionally.
Bear in mind that a reversed throttle could be dangerous with an electric, so you dont want a method that
could be accidentally set, and the other thing is that once its set, you shouldnt need to change it ever again,
even between models.
Its only there to allow for different throttle stick mechanics and once set correctly, thats it.
Also because the throttle stick stays put, you cant us "power up with stick offset" to set reversing
as with the other channels.
So what you do if you build up a new set and find the throttle is the wrong way, is you take a croc-clip lead
or jumper wire , and briefly connect one end to negative ground, ie the mounting bolts or any black wire - and
the other end to the wiper of the throttle pot.
With that connection in place, you switch on, the processor sees the jumper and and flips the throttle channel
direction the other way. Switch off and remove the short or the croc clip jumper, and thats it.
Note it must ground just the wiper, ie the middle tag.
If you were to do it again, it would flip the direction back again, and so on.
If for some unknown reason you wanted to reverse it frequently, you could connect a push-button from ground
to the throttle-pot wiper but for 99% of people I think it just needs to be used once to correct any
throttle-stick anomalies.

At the same time I added the ch5 slow/snap option, using the same technique, on the aileron pot.
To swap between servo-slow on channel 5 and end-to-end snap, you take the same croc-clip lead or jumper-
wire , and briefly connect one end to negative ground, ie the mounting bolts or any black wire - and the
other end to the wiper of the aileron pot. With that connection in place, you switch on, the processor sees the
jumper and and flips the channel 5 function between slow & fast.
Switch off and remove the short or the croc clip jumper, and thats it.
Note it must ground just the wiper, ie the middle tag.
If you were to do it again, it would flip the function back again, and so on.
If for some unknown reason you wanted to choose slow or fast frequently, you could connect a push-button from
ground to the aileron-pot wiper but I assume most people would just settle for one or the other.

10/01/2013: Frsky Bind Board alternative:
On a recent Skyleader Clubman conversion using another V8HT the donor transmitter had a convenient and unused
shrouded button intended for the trainer facility, and a transparent meter through which an LED could be
arranged to shine.
I decided to ditch the bind board altogether, and wire a new LED and the existing 'trainer' button in its place.
Here's the write-up: [LINK]

05/01/2013: Tonight I made a servo movement recorder, or an animation controller, or whatever you'd call it (!)
This is a project without a purpose!
It records 10 seconds of servo movement (the PIC doesnt have a lot of memory) which is retained on power off.
Once a sequence has been recorded, it can run off either a stand-alone battery, BEC or a receiver and cycles repeatedly.
Its very easy to make, just an 8-pin chip, some servo connectors, a button and an LED. Oh, and a decoupling capacitor.
Its all assembled bug-style on the underside of the chip, then heat-shrunk.
If anyone can think of a purpose for this, I'd love to hear about it!
Honestly, all I can think of is animating a pilot or modulating the brightness of night-flying lights with a preset pattern.
Or a varying motor run for a free-flight model?
I've shown it being programmed with an ordinary servo tester, of course you could do the same from a receiver
channel via your tranny. Here's the write-up: [LINK]

Join the Single Channel Revolution!

Phil Green & Shaun Garrity, of the Pontefract PANDAS club

For more information, please email