nRF51 MPU9255 TWI/I2C READ Failed

[makerTim]

Hi all:

I used code from Github to read 9 axis data with TWI. But the example in TWI floder doesn't work.

Does somebody have the same issue?

Chip: nRF51422

Board: PCA10028

Firmware: S130_nRF51_2.0.1

I have checked the TWI pin define, SDA SCL voltage, and the code in mpu_init(). I found a lot of problems in that code. Does somebody have the same issue? Please make a response or even share the ideas with me.

update: I've checked that my module already has 10K pull-up for SDL and SDA. I have found the root cause, I should make SDO (ADO) to low for address 0x68 and SDO (ADO) to high for address 0x69. I still don't know what's the purpose of this design?

[dkwill]

I have gotten those examples working - nRF52 (with the exception of the magnetometer). I just changed the defines in the C/C++ tab and the TWI pins. Make sure to run in SDK 11.0. ADO should be set low for these examples. I used pullups of 10K. They should run w/ no major modification.

[Nilesh]

Hi, I am using nRF52DK board (PCA10040). I changed all pins SDA,SCL pins as per boards in example. I connected MPU-92/65 to nRD52DK using 4 pins - GND, VDD, SCL, SDA. I am using Putty to observe output.
I am getting only output as ---- MPU nRF52 EasyDMA

Please help to get output.

[dkwill]

If you have addressed all the issues I noted above, it should generate output. If not, it is likely a hardware issue. You might try a different Mpu module if all else fails.

[Nilesh]

Yes, you are right. It was hardware isuue. I tried different MPU module. Now I am getting accelerometer values. Thanks a lot! Now I am trying nrf5-ble-mpu-simple. I want to see Accelerometer data on mobile. I am trying to connect nRF Toolbox. Can you please advice me where to observe data over BLE?