Timeout instead of "Entered eflash_loader"

[vasekch]

I have a Sonoff clone called Switch-WF on which I'd like to have custom code, after disassembly I've found BL602 inside.

After some fiddling I've found GPIO 8 and how to pull it high for flashing.

In general I follow https://lupyuen.github.io/articles/flash#flash-the-firmware

This is where I'm stuck, I'm getting timeout instead of entering eflash_loader.

Thanks for any ideas.

$ blflash flash sdk_app_helloworld.bin --port /dev/ttyACM0 
[INFO  blflash::flasher] Start connection...
[TRACE blflash::flasher] 5ms send count 55
[TRACE blflash::flasher] handshake sent elapsed 189.791µs
[INFO  blflash::flasher] Connection Succeed
[INFO  blflash] Bootrom version: 1
[TRACE blflash] Boot info: BootInfo { len: 14, bootrom_version: 1, otp_info: [0, 0, 0, 0, 3, 0, 0, 0, 85, a9, a8, 4c, b9, 7c, 19, 0] }
[INFO  blflash::flasher] Sending eflash_loader...
[INFO  blflash::flasher] Finished 2.546792544s 11.22KiB/s
[TRACE blflash::flasher] 5ms send count 500
[TRACE blflash::flasher] handshake sent elapsed 4.711691ms
Error: Timeout while running command

I've also tried lower speed using -b 115200, but no change.

Chip says: BL602L20