by poirierp » Thu May 01, 2014 8:07 pm
I have done some research here and found some very interesting results. There does appear to be some bad solder joints that are definitely causing the occasional issue. However, I am still getting units that seem to work randomly and stop randomly. I have noticed that on start-up the communication to the DIMU is SPI running at roughly 650KHz. Then very quickly afterwards the clock rate jumps to over 10MHz which then doesn't always result in data being sent back from the DIMU. I managed to read the part number of the IMU chipset and get its datasheet and was able to determine that the maximum recommended operating clock rate for SPI is only 1MHz which is 10 times less than what it appears to be operating at!!! Could this be the source of a lot of issues for those that have more knowledge of the design?