More Skyleaders

[Martin]

These two have just been donated to me by "Old Bill" (who is 98 years old, and now flies using more modern equipment). I've not cleaned them up or inspected them yet. I don't know anything about them really.

The Clubman has a small push button on the top left of its case, and a hole next to that. Is the push button a standard thing, and what might have been in the hole? Maybe I can restore whatever it used to be?

[Martin]

I've had in mind an idea for a while, so maybe I'll implement it on one of these. The idea is to do a conversion but instead of using a regular Arduino as the 'brain', I'll use an ESP8266 or ESP32. They have similar functionality and cost to the regular Arduinos (and can be programmed using the Arduino IDE) but they have built-in WiFi and Bluetooth capability.

Rather than use a display and buttons on the transmitter case to select model memories set up servo travel and such, you'll just link to the transmitter using your smartphone or a tablet, and use the display and touchscreen of the phone/tablet to make the changes. I'll probably just code the ESP to generate 'web pages' that can be accessed from the browser on any phone or tablet - that way there is no need to write different apps for Android and Apple - and there will be nothing to install on the phone/tablet - just connect to the transmitter which will act as a WiFi hotspot, and away you go.

The advantage is that the transmitter will look completely standard, but you'll still have access to a display and touchscreen to make adjustments when you need it.

[Shaun]

Hi Martin,
From memory the hole was for the xtal and the button for using in teacher /pupil mode but I may have it wrong.

Cheers,

Shaun

[PaulJ]

I can confirm what Shaun has said...... The hole was for access to the crystal and originally had a rubber blanking plug to seal it. The button was for Teacher/Pupil and in my own conversion of a Clubman I kept this button in place and used it as the Binding button.

Paul

[Martin]

Thanks. Now I've looked I can see the crystal connector underneath the hole, and the Courier has a similar hole/missing crystal on its back surface. No obvious buddy box button on the Courier, though it does have a similar DIN socket which I guess was a combined buddy-box and charger connector.

Not taken the backs off yet - maybe tomorrow.

[tiptipflyer]

Hi Martin,
your idea with the ESP8266 sounds great. Looking forward to hear more if you decide to follow it.

Frank

[Mike_K]

Hi Martin

I tested an ESP8266 for this type of application with a Skyleader TSX a year or so ago, but didn't get on too well. An ESP32 would solve many, but not all of the issues.

The ESP8266 only has a single ADC, so I had to use a separate multi channel ADC module (or another standard Arduino) to read the joysticks, I used a generic ADS1015 module with I2C. The ESP32 has 16x 12 bit ADC so plenty for all the joysticks and auxiliaries on a transmitter, so would solve that issue.

The ESP8266 didn't have an Arduino CPPM output library that I could find back then, so I modified the servo library. The problem was every time I served up a web page, all the servos would jitter. It may just have been my buggy implementation, but I could never solve it. As the ESP32 has 2 cores, I assume one core is dedicated to I/O and the other the Wi-Fi/web pages, so it may solve the problem. And I expect a better programmer than me may have done a suitable library by now. This wasn't a “show stopper” though, as you'd never be flying while adjusting settings on your phone, though was frustrating while trying to set servo throws etc.

The biggest issue I had was putting the ESP8266 in a metal cased transmitter like a Skyleader, you got virtually no Wi-Fi signal, not enough for reliable connection to my phone without taking the back off. The only bits that aren't rf shielded are the joysticks (and these are chromed plated plastic on many transmitters like the Skyleader SLX, TS/TSX and Courtier Special models), the charging DIN plug and the hole for changing the xtal, the rest is all metal. At this point I gave up and continued development of putting a LCD or OLED display and switches behind the front label, as I find this just as convenient at the field.

So before you get too far, try popping an ESP8266 or ESP32 inside one of the Skyleader’s and see if you have the same “no Wi-Fi signal” issue as me. I only tried one ESP8266 and another may have better rf output and work OK for you. But I wouldn't want you to waste too much time, just to find it wouldn't work how you hoped.

Cheers Mike

[Martin]

Thanks guys. I'm probably not going to get around to this any time soon as I have several other projects on the go already!

The Courier does have plastic sides, so I guess that's the one to use.

I've read that the ESP32 analogue inputs are noisy, non-linear, and vary from one chip to the next, so maybe it's best to avoid using those unless and until Espressif sort out the problem.

An option would be to retain the Skyleader encoder board, (which as you can see in the photo looks in great condition and appears to have headers for seven separate pots/switches) and read the resulting CPPM signal into the ESP chip - that way I'd only be using one digital input to read the position of all the sticks / pots / switches so maybe I could use an ESP8266 - even just the ESP01 (though I'd probably change the flash chip to something bigger than standard).

But I suppose if other people want to build one, it would be best to use analogue inputs - so as Mike says, may be better to use an Arduino or some other separate multi-channel analogue input board.

Some of the newer Arduino boards have WiFi - the new UNO also has gyros and accelerometers though it's still advertised as 'coming soon' There have been previous 'coming soon' Arduino boards that never materialized and were eventually dropped, so I won't hold my breath.

[Mike_K]

Martin

Using the existing encoder with an Arduino as a "post encoder processor" is a great idea, you don't then need to use any analogue inputs. And yes the Skyleader Courier has plastic sides so should be good for Wi-Fi as would a Futaba M series, Micron PL7D, later Fleets and Sprengbrooks and others.

When I get back from my holiday I'll test out a few ESP32 to see if the ADC is linear and repeatable.

The ESP8266 only has a single ADC,

...which isnt even brought out on the ESP-01....

Phil, you must have a different board to me as my V12 has a pin marked as ADC that worked OK.

Cheers Mike

[Phil_G]

Hi Mike, your v12 is a different board to the ESP-01. The ESP-01 is the tiny board thats very popular, its 8-pin header only has a couple of GPIO's, plus the ones used for serial, the processors ADC pin isnt brought out to the header: