[Solved] Issues Flashing Tongou TO-Q-SY1_163JWT 63A Breaker with Openbk Using CH340G-2

Hello, I have a question about this Tongou TO-Q-SY1_163JWT 63 Amp Breaker.

I am having difficulty flashing it with Openbk. I am familiar with the process and have successfully flashed other switch devices eg: [BK7231N] Aubess Mini Switch 16A.

I use a USB / TTL serial device from China CH34 0G-2 which has worked well in the past plus I swapped it out with an identical spare to confirm functionality.

I am using the latest flasher bk7231flasher_1.3.3

Attempts at flashing in place were unsuccessful so I decided to remove the CBU from the main board but still unsuccessful! Resetting the module by earthing CEN does not start the flash sequence (have tried many many times). Also trying another 3.3 v power source, swapping rx1 and tx1 on uart1 just in case but to no avail! I have a log output from uart2 but won't post it here as it may contain private details!

Attaching it to Tuya Smart app all works OK, noticing the firmware is V 1.0.20. Is it possible that Tuya have disabled flashing (bootloader rom) somehow? I do notice on their web site "Flash and Authorize CB Modules"
https://developer.tuya.com/en/docs/iot/CB-series-module?id=Kbruyciad6154


Any tips or advice appreciated
R

I think this device may be using RX/TX to communicate with another chip. What is the marking on the SOIC chip on the other side of the board? Is it BL0937?

Can you check with multimeter where RX/TX connects?

Maybe you need to desolder either CBU or the SOIC chip...

Sounds like @Wobbie has already removed CBU.

How about a different USB-TTL adaptor?

Ah sorry, I see. Well, then maybe the CBU needs a better 3.3V power supply.
https://www.youtube.com/watch?v=L6d42IMGhHw&l...CZDbczAXT94BuSGrd_GoM&ab_channel=Elektrodacom

Thanks @p.kaczmarek2 and @divadiow
As mentioned I have tried a different 3v3 power source.

What USB-TTL adaptor do you suggest?

Part of the captured uart2 output:
V:BK7231N_1.0.1
REG:cpsr spsr r13 r14
SVC:000000D3 00401C1C 000033AC
IRQ:000000d2 00000010 00401e0c a19cdfd3
FIR:000000d1 00000010 00401ffc b887f1e0
SYS:000000df 0040192c 00000158
ST:00000000
J 0x10000
bk_misc_init_start_type 0 0
prvHeapInit-start addr:0x411448, size:125880
[Flash]id:0xeb6015
[01-01 18:12:15 TUYA I][lr:0xa54bd] mqc app init ...
[01-01 18:12:15 TUYA I][lr:0xb04ef] thread_create name:sys_timer,stackDepth:4096,totalstackDepth:4096,priority:5
[01-01 18:12:15 TUYA I][lr:0xb04ef] thread_create name:cmmod,stackDepth:4096,totalstackDepth:8192,priority:4
[01-01 18:12:15 TUYA D][lr:0xb037b] Thread:sys_timer Exec Start. Set to Running Stat
[01-01 18:12:15 TUYA D][lr:0xa53d7] mq_pro:5 cnt:1
[01-01 18:12:15 TUYA D][lr:0xa53d7] mq_pro:31 cnt:2
[01-01 18:12:15 TUYA D][lr:0xd5f5b] svc online log init success
[01-01 18:12:15 TUYA D][lr:0xcd37f] read m:0 f:0 l:0
[01-01 18:12:15 TUYA I][lr:0xb04ef] thread_create name:wk_th-0,stackDepth:5120,totalstackDepth:13312,priority:3
[01-01 18:12:15 TUYA E][lr:0xb43c9] wd_protected_read fails gw_bi -23
[01-01 18:12:15 TUYA D][lr:0xb463b] gw base read finish:-23
[01-01 18:12:15 TUYA D][lr:0xd3b17] ty bt cmmod regist ok:1
...
...secret stuff!
...
[PLATFORM DEBUG]UNKNOW EVENT:16
[01-01 12:00:04 TUYA E][lr:0x5ac01] ERR BL0942 read
[01-01 12:00:05 TUYA E][lr:0xd6b29] uf_open netcfg_log err 8
[01-01 12:00:05 TUYA E][lr:0x5ac01] ERR BL0942 read.

can send the entire log via PM if you like?

Wobbie wrote:

What USB-TTL adaptor do you suggest

I was clutching at straws with that idea really. I think maybe a different USB TTL has only made a difference once or twice for me in the past and that was probably when I wasn't soldering contacts or had the cables too long. Not needed to swap for a long time.

What is your PSU now?
Got any pics of your setup?

Added after 58 [minutes]:

here's a backup/flash I've just done from CBU using a CH340 USB-TTL and external 3.3v PSU

Well my flasher just ignores the fact that I either earth CEN or re-power the CBU! (multiple times)
I'm using the same driver

PSU is an adjustable one set to 3v3 (using a multimeter)
Here is my setup

Ah. Are you able to shorten your wires as much as possible?

Yes, I tried that this afternoon with no luck.
I also connected a tuya IR Blaster which I converted a year ago successfully and did a firmware read or backup using the same hardware, went perfectly.
Not sure what's going on!
Is it possible tuya have upped their game more? Locked the bootloader somehow?

Use shorter wires, especially for power, and you can also use higher 3.6V voltage

I'm not entirely sure how but I have seemingly killed tx and rx on a CB3S before. It boots into OBK fine but Rx and tx are dead for any USB TTL or any cables or any adaptor.

Worst-case you could replace the CBU for another, assuming something similar has happened to yours?

I have flashes hundreds of devices and I haven't seen any with "locked bootloader". I would keep investigating the circuit.

I'd suggest trying the USB to UART converter that I use:



Try alternate RESET method:
- connect only RX, TX, GND and 3.3V
- start flasher
- disconnect 3.3V from CBU
- temporary short the GND to the 3.3V pin of CBU
- disconnect the short of CBU 3.3V to gnd
- connect 3.3V from supply to CBU
It may sound strange but it worked for me in some cases where the little current sinked by TX/RX lines alone (without VDD) was enough to keep CBU alive so it didn't reboot on power off/on

Thanks everyone, found my problem; RX connection got broken going into the CBU when removing from the main board (not enough flux I think)! Managed to fix it so happy ending.