I’m using several Colibri T20 V1.2 modules with WEC7 image V2.3 and Toradex libraries V2.4.
I found a strange behavior while interfacing the SPI3 port.
In the application the SPI3 port is mapped to the pins:
CLK = 192
MOSI = 49
MISO = 51
CS0 = 53.
Sometimes, when the application starts, the MISO line of the module reads only 0xFF, but the MISO line on the PCB shows the correct data is transmitted from the device.
I first assumed there might be two pins configured as SPI3 MISO and one is pull-up, but the GPIOConfig tool shows only one pin at the MISO line.
During the tests it looks like there might be a temperature influence. If the Colibri module heats up, the propability of the issue during the software start increases.
I used the Update Tool to perform different startups. The problem appears only after a “coldstart”, and never when the system is running. It seems to disappear when the system is send through a “warmstart”.
Is this behavior known, and is there a workaround?