Will this FW work on a Lilygo T-Embed Si4732 radio?

[oar9fi]

My beloved ATS-MINI has given up its magic smoke today (RIP) I was going to order another, and saw this for about the same price. My question is, will this firmware work on it? I couldn't find much but here is a link. https://lilygo.cc/products/t-embed-si4732
Is it simply a different case on an ATS- MINI or what? Thanks and best regards, Justin.

[max-arnold]

I'm waiting for mine to arrive

[max-arnold]

No, the firmware will not work on T-Embed Si4732 because of a different hardware pinout and lack of power switch. Some changes are necessary, but I do not have time to implement them at the moment.

[oar9fi]

Thanks for checking, I just went ahead and got another ATS Mini. 73, -Justin N2UJZ

[G8PTN]

Hi Max,
For interest, "Volos Projects" has generated an initial alternative firmware for the T-Embed Si4732.
https://github.com/VolosR/VolosMiniRadio

There is also a short demo video on YouTube.

The lack of power switch is not so good. Perhaps there is some way to add a soft power switch with a MOSFET, I have not checked what is on the schematic for the T-Embed.

73, Dave

[max-arnold]

Hi Dave, thanks for the link!

The biggest downside of T-Embed Si4732 (besides the horrible encoder control in the stock firmware) is lack of power switch. In sleep mode the circuit drains the battery in a couple of days.

Recently I implemented multiple build artifacts support in the Github CI workflow, so it will be possible to add a -lilygo variant in addition to ospi/qspi builds. I'll try to adapt the ats-mini firmware later when I have some time.

[johnlaur]

@max-arnold I found this thread looking for information about this. I would perhaps be able to assist with making the build variant but do not want to duplicate any work. If you have thought about the needed changes and have a mental list, I'd be happy to take a look if you would consider a pull request.

[max-arnold]

@johnlaur I'll be happy to accept a PR if it isn't too disruptive. I think you could start with adding a compile-time option like TARGET_LILYGO or something like that and use it in a couple of #ifdef statements to redefine the pinout (here is how to specify it for arduino-cli). That would be a good start.

Other things that need to be done (there could be more, as we move forward and discover new obstacles):

1. Add a new artifact to the CI workflow (I can do it if you need some help with that)
2. Change the preferences reset logic (the encoder button is used to wake up the receiver and could inadvertenly reset the settings)
3. Find a way to put the receiver back to deep sleep (right now long press is used to switch the display on/off)

Alternatively, instead of (2) and (3) we could advice users to install a hardware power switch that will fix the battery drain issue. At least that is what I plan to do with my receiver.

[max-arnold]

Did any of you manage to find the receiver schematics? So far I found the following links but they do not have the Si4732 shield board schematics:

• Wiki https://github.com/Xinyuan-LilyGO/LILYGO_wiki/blob/main/docs/get_started/en/Wearable/T-Embed-SI4732/T-Embed-SI4732.md
• Main board (?) https://github.com/Xinyuan-LilyGO/T-Embed/blob/main/schematic/schematic.pdf
• FW binary https://github.com/Xinyuan-LilyGO/T-Embed/blob/main/firmware/SI4735_Shield_250308.bin
• FW source https://github.com/Xinyuan-LilyGO/T-Embed/tree/main/examples/SI4735_Shield

[johnlaur]

@max-arnold Thanks so much for the detailed info. I can get all of that done no problem. I have zero familiarity with the structure and operation of this code, so it's an immense help to get your intuition on the task. It might be a few days before I can start.

No schematics for the shield board that I had located so far; this is the code for the shipping firmware. I presume you found that since you discovered that this is the schematic that is missing! Black PCB makes it slower to trace but if there is a question about the hardware that cant be answered by the source code, I am happy to assist with that.