Accelerometer Example of New Crio

[zlong]

We also struggled with the ADXL345 in I2C mode. Running the included LabVIEW example the device worked intermittently. I looked at SDA and SCL with an O-Scope and noticed they where kind of floating when communication had error-ed out. My fix for this was to place a 100 ohm pull up resistor on both SDA and SCL. This made the ADXL345 perform wonderfully on the I2C bus. We have implemented this fix on our robot and so far have been very happy with the ADXL345's performance.

[Joe Ross]

Originally Posted by zlong

We also struggled with the ADXL345 in I2C mode. Running the included LabVIEW example the device worked intermittently. I looked at SDA and SCL with an O-Scope and noticed they where kind of floating when communication had error-ed out. My fix for this was to place a 100 ohm pull up resistor on both SDA and SCL. This made the ADXL345 perform wonderfully on the I2C bus. We have implemented this fix on our robot and so far have been very happy with the ADXL345's performance.

100 ohms seems like a lot for I2C to me. The [url=http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2012_Assets/Digital%20Sidecar.pdf]Digital Sidecar is supposed to have 3.16k on SDA and SCL. Can you check if those pullups are working?