Programming fails on flex PCB

[LeoChen]

Hi Gene,

 

One of my customers using our module to pilot run.

https://static1.squarespace.com/static/561459a2e4b0b39f5cefa12e/t/5da77e178970da0cc270ef0d/1571257883383/BM832A_datasheets.pdf

When they put the module on their flex PCBs.

Some of boards has the following problem.

1. The device fails to program occasionally (just disconnects).
2. Sensitivity to power draw (module resets when gpio turns on sensor power island) or when turning on BLE Advertising.

Attached the good and bad programming scope from our customer.

Do you have any idea what will cause this problem?

Thanks for your help.

[Amanda Hsieh]

Hi, 

What programmer do they use? 

How the boards are powered. E.g. is it battery powered ? If yes, then what type of battery is used? What is the voltage supplied to the chip? Please make sure the voltage is 3.3v. 

-Amanda H.

[LeoChen]

Hi Amanda,

My customer have concluded it isn't the module, but a cold solder joint on swdio or swdclk.

Thanks for your support.