Second IMU appears to be overwriting or corrupting imu data
  • Hi all,
    I'm got a SimpleBGC with two imus, with firmware 2.69b2. However it appears the two imus are overwriting each other. I have cut the address signal on the Frame imu and confirmed that there is no continuity between the two sides. but when I use the monitoring tab to look at the raw data with both imus connected I get acceleration fields that have a jumpy +1024 (10 bit) field. The jumpiness seems to be a bit frame error because it jumps from ~1018 to 512.
    This only occurs when the second imu is installed. When I use the imus singly they report accelerations in the range +- 512. Is anyone aware of a address bug in the system, or could it be possible that the addresses for the two frames may have gotten corrupted, ie is it set in a param location. It seems the system thinks they have the same address, because when they were tested singly they both showed up as the main IMU.
    I had to flick the "Swap frame and main IMU" to get them to not be considered at the same address.

    Has anyone had this issue and can suggest workarounds.
  • I note the Data sheet for the IMC 20602 requires pullups on all pins. If I cut the wire do I then require a pullup resistor on the pin to get 0x69 address.
  • Apparently you are describing the address selection issue. Look at tis page https://www.basecamelectronics.com/i2c_imu/
    (FRAME IMU SELECTION: to use it as a secondary (frame) IMU, it's not enough to cut the «ADDR» bridge. It's required also to solder a piece of wire)