Problems encountered in debugging B-U585I-IOT02A WIFI module

littleshrimp

Problems encountered in debugging B-U585I-IOT02A WIFI module [Copy link]

Yesterday, when I was testing the WI-FI routine, it prompted "flow is low wait flow timeout 0", and I suspected that there was a problem with the WI-FI module. Today, I used an oscilloscope to test some pins of the WI-FI module. The NLWRLS.FLOW pin had no level change, and the MOSI pin only had a level change but no data.

I was wondering if this board needed to be flashed with the WI-FI module firmware before it could be used, or if someone had used this board before and modified the WI-FI module firmware, so I followed the instructions in the manual um2839-discovery-kit-for-iot-node-with-stm32u5-series-stmicroelectronics to upgrade the EMW3080 firmware.

First, I downloaded the compressed package from the URL below, upgraded the EMW3080updateV2.1.11RevC.bin firmware in it, turned the SW2 switch to 0, then reset the development board, and pressed the blue button to start flashing the firmware.

https://www.st.com/content/my_st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-utilities/x-wifi-emw3080b.license=1633145666596. product=X-WIFI-EMW3080B.version=1.0.0.html

en.x-wifi-emw3080b_v1.0.0.zip (22.03 MB, downloads: 1)

2021-10-2 11:55 上传

点击文件名下载附件

Normally, it should show success as described in the manual, and then the green light should flash. However, mine shows various Noacks, and there are endless Noacks.

I wondered if I had turned the switch wrong or there was a communication problem, so I turned the switch back to its original position. When I downloaded again, it prompted "STM32>EMW3080 bootloader failure, please move switch to force Boot pin to GND and reset board". This shows that at least the original switch was correct, and the communication between STM32 and EMW3080 was normal, but I still couldn't figure out why it prompted Noack.

Because there was no sealing tape on the anti-static bag when I unpacked it, I was not sure whether the board was brand new. I carefully observed the board and found that although there was nothing unusual about the welding of EMW3080, there were obvious signs of re-soldering on the pins of CN2 and CN1.

The four solder joints on the right side of CN2 are much brighter than those on the left, and there is also a lot of flux residue on the board.

CN1 looks even worse

Other places on the board are also greasy, which is a rather troublesome problem and makes me wonder if some functions of this board are really broken.

Jacktang

I don't think this is a repaired board.

Desoldering

It may also be that the board was manually welded and the welding slag was not cleaned.

littleshrimp

Jacktang posted on 2021-10-2 17:19 This is not a board that has been repaired. It may have been desoldered or the board was manually soldered without cleaning the solder slag

I'm not quite sure why the soldering had to be done. In one picture, solder oil fell on the "SE" label, indicating that the label was affixed first and then the 4 pins were soldered.

yangjiaxu

As for WiFi, it is quite simple. You can upgrade the firmware or not. Basically, you don’t need to do anything. If you use their demo, it is the serial port assistant. If the encoding format of the serial port assistant is not correct, the sent data will not respond.