[Request] Arduino allow FTDI/Pasthrough to allow ExpressLRS updates

[ramiss]

Hi There,

Since many FTDIs are made from Arduinos, could HeadTracker add a feature to kick the UART into passthrough mode to allow for ExpressLRS updates, like Betaflight does? Would save a lot of de-soldering, and great for those that don't own an FTDI

Thanks for all you do!

[rotorman]

Your feature request has not much to do with the HeadTracker project.

Have a look if https://hardwarefun.com/tutorials/using-arduino-as-a-bridge-to-connect-serial-devices-with-pc suits your needs.

Also to get terminology straight: "Future Technology Devices International Limited" is a company behind https://ftdichip.com/ that manufactures one of the most popular USB-to-serial adapter chips. An abbreviation "FTDI" is commonly used to denote USB to serial adapters, also (wrongly) from differing manufacturers (e.g. Silicon Labs CP2102, Nanjing Qinheng Microelectronics Co., Ltd. CH341).

Under "Arduino" you can mean a company Arduino S.r.l., or the development boards, which it develops and manufactures. The development boards have a microcontroller that is programmed and most often can also communicate via virtual serial port with the computer. Some boards have an added physical serial-to-USB chip on-board, and some boards come with microcontrollers with embedded USB connectivity. Latter you could turn into a serial-to-USB adapters with a brief bi-directional bridge firmware relaying all data between the two communication ports. Most often this will although not achieve the same maximal baud rates, as the physical USB-to-serial chips do.

[ramiss]

Ah, I see you aren't aware that many people are now using ExpressLRS receivers as transmitters to communicate the headtracking signal to the transmitter. AndyRC put out a video on this.

The problem is that, to update the ExpressLRS tx connected to the arduino headtracker, one must desolder and connect to an FTDI. It would be very useful if Headtracker "acted" like an FTDI (UART passthrough) to allow updates.

[rotorman]

You are talking about https://www.youtube.com/watch?v=DK2tTd7Q0xk
You can update ELRS gear via WiFi as well, so no NEED for serial-to-USB adapter change.

But if you insist, then you can flash your Arduino Nano with a serial-to-USB bridge Arduino code of your choice and then when you are done, flash it back to HeadTracker. I do not see this feature being required to be implemented in a more user friendly way in the HeadTracker codebase in order to cater this corner case.

[ramiss]

Actually, you can't update an ELRS receiver acting as as transmitter using wifi - hence the reason for this feature request.

[rotorman]

Hmm... are you sure? By looking at the ExpressLRS source code, the RX-as-TX option does load up the normal (internal ELRS RF module) TX stack, which also includes WiFi updating.

[ramiss]

Yup. its been broken for a long time. This was my post in the ELRS Discord and a response from one of the experts:

[rotorman]

Here the code, you can either then provide a .bin or .bin.gz accordingly to in which mode the flashed code currently is:
https://github.com/ExpressLRS/ExpressLRS/blob/19d6381ae2729c6069c7c7a6bf940d9fdf63c293/src/html/scan.js#L520-L529
You could also alter the code to accept bin.gz also in TX mode.

ExpressLRS Configurator works with this script (which you can also alter):
https://github.com/ExpressLRS/ExpressLRS/blob/19d6381ae2729c6069c7c7a6bf940d9fdf63c293/src/python/binary_configurator.py#L268-L272

[ramiss]

Here the code, you can either then provide a .bin or .bin.gz accordingly to in which mode the flashed code currently is: https://github.com/ExpressLRS/ExpressLRS/blob/19d6381ae2729c6069c7c7a6bf940d9fdf63c293/src/html/scan.js#L520-L529 You could also alter the code to accept bin.gz also in TX mode.

ExpressLRS Configurator works with this script (which you can also alter): https://github.com/ExpressLRS/ExpressLRS/blob/19d6381ae2729c6069c7c7a6bf940d9fdf63c293/src/python/binary_configurator.py#L268-L272

I know it is supposed to work that way, but it doesn't. It throws the error "Not Enough Space". Try it. Prove me wrong. I've tried many times, with different receiver makes and models, and posted in the Discord as seen above.. The reality is that the ELRS devs wont fix it for this use case and just tell me to flash through a flight controller.

[ramiss]

Ok, figured it out. You have to rename the ".bin.gz" file to ".bin" and then upload. Closed.