adcStart breaks i2c on stm32l432 ?

[geoffrey.brown]

I have an application on an stm32l432 which uses both i2c and adc. i2c works fine except if I execute

adcStart(&ADCD1, NULL)

the adc works fine once I start it, but if the adc is started, the i2c i2cMasterTransmitTimeout(..) command returns an error code -- even if the only adc command executed is the adcStart command. Something in the initialization code is stepping on the i2c, but I haven't got a clue where to look.



Kernel: 4.0.0
Compiler: GCC 5.4.1 20160609 (release) [ARM/embedded-5-branch revision 237715]
Architecture: ARMv7E-M
Core Variant: Cortex-M4
Port Info: Advanced kernel mode
Platform: STM32L4xx Ultra Low Power
Board: STMicroelectronics STM32 Nucleo32-L432KC
Build time: May 30 2017 - 18:45:04

[Giovanni]

Hi,

Is there a DMA conflict? check the channel assigned in mcuconf.h.

Moved in STM32 support.

Giovanni

[geoffrey.brown]

There doesn't seem to be a channel conflict -- ADC1 is on channel 1, I2C1 on channels 6 & 7.

Geoffrey

[Giovanni]

I have no clue of what could cause this...

Is it just adcStart() or also some pin mode change or other things?

Giovanni

[geoffrey.brown]

Just executing adcStart is sufficient to break I2C.
Geoffrey

[Giovanni]

Is adcStart() placed before i2cStart() or after? does it make a difference? are debug options enabled in chconf.h?

Giovanni

[alex31]

Students of mine have made a project, (an autonomous stoplight for bicycle) using stm32l432, they use I²C for IMU access, and ADC for testing battery level, and they did not mention me any incompatibility problem between I²C and ADC on stm32l432.

Alexandre

[geoffrey.brown]

I look elsewhere in my code for the problem.
Geoffrey

[RoccoMarco]

You could also share us the main...