Developing my first ElectricImp imp004m PCB and troubleshooting the circuitry. I’ve had trouble programming the MX25R8035F SPI flash and had assumed the BlinkUp LED was flashing red as a result but when I power-up and monitor the SPI pins (MOSI/MISO/SCK/CS) they don’t appear to change state at all. My question is, what is the order of operations and am I chasing the wrong fault? If the SPI flash isn’t being polled first what is causing the hold-up and flashing red LED?
After finding this topic Bringing up a new board which described my red BlinkUp flashing pattern more concisely I went back and double-checked my board. I reflowed the imp004m to the PCB and it is now working!
My concerns about the method of programming the SPI flash were squashed (I’m using the Adafruit FT232H and their ftdiflash program which always results in a ‘found difference between flash and file’ error).
The Dev Center is your friend:
The imp004m design guide has a list of SPI-related error codes that may get flashed on the BlinkUp status LED at start-up.
General BlinkUp codes can be found here.