nRF51 MPU9255 SPI READ Failed

RE: nRF51 MPU9255 SPI READ Failed

makerTim — Tue, 04 Apr 2017 16:10:17 GMT

I solved it. It was wrong because my MPU9255 was connected to 5V. The chip select Pin is also 5V, and this cause the CS pin can't draw the voltage down to 0V. I measured 3V on the CS pin when connected, and 0V when CS pin unconnected.

RE: nRF51 MPU9255 SPI READ Failed

Jørgen Holmefjord — Tue, 04 Apr 2017 12:23:58 GMT

Do you configure anything else in your code that use P0.04?

RE: nRF51 MPU9255 SPI READ Failed

makerTim — Tue, 04 Apr 2017 11:32:31 GMT

I found the root cause, the chip select on Pin 4 didn't work. Why?

RE: nRF51 MPU9255 SPI READ Failed

makerTim — Tue, 04 Apr 2017 09:19:55 GMT

MPU9255 was set, but the data was still wrong.

ff.PNG

[1B][2J[1B][;HMPU BLE simple example. Compiled @ 17:15:28. [1B][2J[1B][;HAccel: 00000, 00000, 00000 Accel: 00, 00, 00, 00, 00, 00 [1B][2J[1B][;HAccel: 00255, 00255, 00255 Accel: 00, 0xff, 00, 0xff, 00, 0xff [1B][2J[1B][;HAccel: 00255, 00255, 00255 Accel: 00, 0xff, 00, 0xff, 00, 0xff

RE: nRF51 MPU9255 SPI READ Failed

Jørgen Holmefjord — Tue, 04 Apr 2017 09:12:50 GMT

Have you tried the example on GitHub without changes (only make sure you set the correct sensor model define MPU9255? What values are you getting from this?