Firmware for FCC testing on P1

I am working on product which uses particle P1. It is currently going through FCC testing. Need help in figuring out the current firmware for running the tests. The product also has a BLE module hence the firmware is needed to perform the co-location test.

  1. The download in the certification guide has 2 sets of binaries BM-09 and BM-14. Which is the correct set of binaries for P1?
  2. The tests are run with commands on a UART port. Which UART on P1 is used for this? Could not find this in the document/guide contained in the download.

I have tried flash the firmware however the scripts provided give the following error(Reading CDC header failed) :

The serial port is connected to PA9 and PA10 pins on P1.

The RX and TX pins are properly connected to USB-Serial. I get the following message on terminal upon boot:

Any pointers to resolve will be great!


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This was a huge struggle. There was no clear documentation of why this was happening. Even after indicating that the issue could be with the bootloader checking certain pin upon boot, the support did not help investigate or find more info from the module vendor. We finally figured it out with lots of trial and error. The culprit here is pin 40 (MICRO_GPIO_1/PB0). Our product had this pin driven low whenever a peripheral was connected to this pin. The bootloader in FCC test frimware checks this pin and if it is low, erases the flash :frowning:

So ensure that either pin 40 (MICRO_GPIO_1/PB0) is not used in your product or it is pulled high. This was really a nightmare. We had to reschedule the FCC test for the product because of the issue which cost us money and huge loss of time!


@explorer, we are trying to flash these testing binaries onto a device that doesn’t have JTAG installed? Were you successful? If so could you report your procedure? Would be very helpful!

SWD pins are needed to re-flash the firmware as the boot-loader needs to be replaced.

My issue was that PB0 was used by a sensor and that causing issues upon reboot with the FCC test firmware.

Hi explorer
I am using Photon,I have the same issue.
But the pin name not the same as P1.
How did you find out which pin must not pull down?