About jansen

jansen · 2014-10-03

Posted on October 03, 2014 at 16:52System info: 8MHz external clock, 24MHz interrupt system clock.Interrupt preemption is not working for me no matter the combination of priorities and priority groupings. My goal is to have a high speed timer interr...

jansen · 2015-10-21

Posted on October 21, 2015 at 16:59Be careful using this device and several others from ST over SPI. If you are sharing the SPI bus, the notion of Chip Select (CS) doesn't work right. This device and others, when NOT selected are actually in I2C m...

jansen · 2015-10-21

Posted on October 21, 2015 at 16:02''So is it possible to use SPI to the EEPROM when LIS3DH CS pin is high (the LIS3DH would be in I2C mode)?''NO, this will likely go badly for you (if it hasn't already). Several ST devices don't use the notion of ...

jansen · 2015-10-21

Posted on October 21, 2015 at 15:44''Also, CS pin is used to put sensor into SPI / I2C mode, so when SPI communication needs to terminated, MCU will have to drive CS=high, this will in turn put sensor into I2C mode, is this not conflicting ? ''YES t...

jansen · 2015-03-13

Posted on March 13, 2015 at 19:15Read the errata and app note, they talk to the requirement to set the STOP bit very early, protecting from timing and interrupt concerns, etc. If you don't follow this, there are bit issues that cause various proble...

jansen · 2015-03-11

Posted on March 11, 2015 at 15:58I'm not sure if this covers exactly what you are seeing, but there is a lot of errata on i2c for these chips. Using polling methods is the worst. Basically, either manually bit-bang i2c without using hardware suppo...

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STM32F101RD: Interrupt preemption not working

Re: LIS3MDL high nonlinearity for negative magnetic fields

Re: Use LIS3DH on the same SPI bus as an EEPROM, is it possible?

Re: LPS331AP - SPI mode - Multiple slaves sharing common SPI bus

Re: Invalid clock pulse on I2C

Re: Invalid clock pulse on I2C