Hi, PLEASE HELP!
We have some Honeywell ABP2…S… on one SPI-Bus. Only one answers. It is always that one, that is selected first after a power-cycle. The others sends only 0 (pulls MISO low). If I start the cycle with an other sensor, then that one sends and the previous one fails (ONLY after a POWER-cycle).
The hint of the additional “reset” in the datasheet is done (activate CS, wait (1-2ms), deactivate, wait 5 ms, then do it with the next sensor) - but without success. Only a power-down-up-cycle changes the behaviour.
The signals (CSx, Clk, MOSI & MISO) looks fine.
Do you have an idea? Thanks a lot!!!
Best regards,
Stefan
Hello stefanop and welcome to the DigiKey TechForum.
Have you tried bringing the SS line of each sensor from HIGH to Low, holding that LOW state and then releasing it to HIGH before the very first transaction?
I also found this Technical Note going over SPI communication for Honeywell Pressure Sensors that may be helpful?
Hello Nick,
thanks a lot for your answer! Yes, I did - without success (this is, what I meant with “reset”).
Do you have any other ideas? The low SS (==CS) lasts 1-2 ms instead of “>= 200µs”. I cannot imagine, that this is a problem.
My hope is, that the HAL of ST is not “optimized” for this requirement - and that I can solve it by SW.
Hope for any more suggestions,
Stefan
