7ch Propo + S/C mix encoder update/rewrite

[GardenGate]

Thanks Martin!

Yup, it's hard to understand why Radiomaster went with the four pole 3.5mm connector when their own trainer cable set (https://www.radiomasterrc.com/products/ ... 6s-tx12-t8) clearly is functional with only two wires (and they recommend that just using the mono 2-pole 3.5mm connector is fine):


I'm likely to stick with just a simple 2-pole 3.5mm jack on my vintage Tx conversion.

[Phil_G]

Bear in mind that jack plugs short on entry, protect any signals with a series resistor to keep the magic smoke in

[GardenGate]

It doesn't look to me like DIYMore makes the Pro Strong Mini boards anymore - at least not on their Web site. This one looks equivalent:
https://www.diymore.cc/collections/diym ... or-arduino - agree?

Have any of you tried it? In particular, the newer (?) board has the micro USB instead of the serial header, so the trick of modifying the serial header for outputting to the PPM signal to the RF deck won't be applicable, so I was wondering whether any of you had any experience on using it as a retrofit encoder.

Or how about any of the ESP8266/ESP32 boards - has anyone found one with more than 4 good analog inputs?

[Martin]

The analogue inputs on the ESP8266 and ESP32 chips are not really good enough, nor numerous enough, for making good encoders. The Raspberry Pi pico has better analogue inputs, but only three are available. For these and other chips with insufficient analogue inputs, easiest option is probably to use an external module board, connected by I2C, that provides multiple ADC inputs. There are several common and cheap boards that provide 4 or 8 analogue channels.

[Mike_K]

They still sell them on their official Ali-Express store. I bought some only last week and they've already been delivered.

https://www.aliexpress.com/item/3286515 ... T79Q7mvqzQ

The first "picture" selects the 5V 16MHz Pro Mini Strong, which is what I think you probably want. The picture you've shown is for their version of a Nano, it has a micro-USB port and a CH340G USB to serial converted onboard (just like a regular shape Nano), so you could program it with just a micro-USB lead, but it costs more and I prefer the Pro Mini Strong for experimenting using a USBASP ICSP programmer.

The DM More ESP-powered boards haven't really got enough I/O for an encoder and won't run Phil's firmware (or my F3A modified version) anyhow, so avoid those.

[GardenGate]

Hi Mike - thanks for the pointer to DIYMore store on AliExpress.

Have you tried their version of their Nano? Besides connecting via micro-USB v. the USBASP, any other differences you would note in use?

[Mike_K]

I bought some of their Nanos a year ago by mistake and they worked as expected. But if you are going to use the icsp programmer, they cost more for no additional features.

If you plan to use them for an encoder (which I assume as you've posted it under 7ch Propo + S/C encoder), then they are not ideal. You can't do the convenient modification Phil does for the ppm output to have the battery supply on the same 3-pin header as there is no serial header. In fact, you have a minor problem as the ppm comes out on D0 and this is "covered" by the DIP switch and there is no other convenient place to pick up D0, you'd have to solder to the bottom of the board or similar.

What the Nanos are useful for is development, especially if using the serial monitor to debug as they can be directly connected to a PC with the USB micro port, the Pro Mini Strong need a USB to serial adapter.