I'm trying to develop a remote knock sensor using a Synapse Wireless RF200 device. It has a microprocessor on board and uses a subset of python for programming. Unfortunately, there are no existing libraries for me to use so I'm trying to develop my own. The RF200 supports I2C communications and I have it talking to the ADXL345. By this I mean I can read and write to registers. For example, if I read 0x00 I get back 0xE5 and if I write to other registers I can read back the values and they are what I expect.
I'm trying to utilize the single tap feature. Here's what I do setup the ADXL345:
1) write 0x03 to the DATA_FORMAT register (0x31) - 16 g
2) write 0x04 to the INT_ENABLE register
3) write 0x07 to the TAP_AXES register - all 3 axis
4) write 0x30 to the THRESH_TAP register - 3 g's
5) write 0x14 to the TAP_DURATION register - 20ms
However, I'm not getting any output. What am I missing here?