HTCC-AM02 PCB design RESET button and bootloader mode via RTS/DTR

Hi all, I tried to implement the reference Arduino design for the HTCC AM02 and so far nearly everything works fine. I found however that neither the reset button nor “automatic” bootloader (aka flash) mode via serial is possible. Could someone give me some advice?

It is possible to press both RESET and USR1 button on startup to enter the bootloader mode and firmware flashes fine. However I thought it’s also possible to do this automatically via a RTS or DTR pin?

It’s designed with EasyEDA, if someone is interested in the PCB/Schema files I’ll upload them somewhere

What serial chip do you use to download the program?

I’m using a FTD1232 but I’m happy to switch to whatever else would make it work.

Did you connect the DTR and RTS pins? If FTD1232 doesn’t work, you can try CP2102, and you need to connect DTR and RTS pins.

Thanks for your quick response. I connected both DTR->DTR and RTS->RTS but it doesn’t work. I’ll try to get the CP2102 chip.

Hi @aparcar, I made a custom PCB based on AM02 module. I wanted a solution with minimal components number, I used an external USB UART/TTL for flashing my device and I only integer a reed switch (instead of a button) for Reset.
I shared my newbie schematics (kicad) on https://discord.gg/WTudFKas
Feel free to join, maybe we can share our BOM because I made my PCB on Jlcpcb too.