nrf52 with MPU9255

RE: nrf52 with MPU9255

kirt — Thu, 22 Mar 2018 08:14:18 GMT

i need to add manufacturer data to same example ,sdk14

can you please suggest example to refer for s132?

RE: nrf52 with MPU9255

MartinBL — Tue, 20 Mar 2018 09:13:11 GMT

Do i need to make here 39 instead of 199 ?
Yes.

what changes do i need make if i want to send data only after i write a value to characteristic
I advice you to study the BLE Blinky Application example. It shows how you can turn on an LED by writing to a characteristic. With a little modification you can use this to achieve what you want.

RE: nrf52 with MPU9255

kirt — Fri, 16 Mar 2018 12:00:14 GMT

yes.

1.In the code sample rate set is 5Hz, If i require to change it to suppose 25Hz ,Do i need to make here 39 instead of 199 ?

p_mpu_config.smplrt_div = 199; // Change sampelrate. Sample Rate = Gyroscope Output Rate / (1 + SMPLRT_DIV). 199 gives a sample rate of 5Hz

2.Data is sent directly when i enable the notification after connection to device .what changes do i need make if i want to send data only after i write a value to characteristic ?

RE: nrf52 with MPU9255

MartinBL — Fri, 16 Mar 2018 08:19:02 GMT

If you look on the back side of your kit you can see which pins are already being used for things like UART. In the MPU examples the UART are configured before the MPU in the code. If you "override" the UART configuration and use the UART pins for the MPU then naturally you will not see anything printed to your terminal. This is why I chose to use pin 3,4,28,29 and 30 by default in the examples since they are not being used by anything else.

RE: nrf52 with MPU9255

kirt — Thu, 15 Mar 2018 08:11:59 GMT

Yes .I have set and i have changed INT pin as well ,Because pin 0.08 is is connected to INT pin of mpu9250

#define MPU_MPU_INT_PIN 8

in pca10040.h file these 3 pins are used for

#define RX_PIN_NUMBER 8
#define TX_PIN_NUMBER 6
#define CTS_PIN_NUMBER 7

RE: nrf52 with MPU9255

MartinBL — Wed, 14 Mar 2018 15:07:08 GMT

If you want SDA on P0.06 and SCL on P0.07 you should set:

#define MPU_TWI_SCL_PIN 7

#define MPU_TWI_SDA_PIN 6

RE: nrf52 with MPU9255

kirt — Tue, 13 Mar 2018 09:28:23 GMT

i am using same code for board .I have changed SCL and SDA as follows

In main.c

#define MPU_MPU_INT_PIN 12 //as INT pin10 for given kit .Physical number 12

in nrf_drv_mpu_twi.c

#define MPU_TWI_SCL_PIN 9
#define MPU_TWI_SDA_PIN 8

because Pin p0.06 i.e physical number 8 and P0.07 i.e physical pin number 9

I am not getting values for accel and magneto .please suggest which about pin number/code change

Here i am using nRF52 DK as a debugger/programmer.another h/w is my application h/w

RE: nrf52 with MPU9255

kirt — Mon, 12 Mar 2018 14:10:56 GMT

Yes ...Its working now with both SPI/TWI.

RE: nrf52 with MPU9255

MartinBL — Mon, 12 Mar 2018 13:13:12 GMT

Here you go:

Did you try my test hex file?

Note that I have bypassed the voltage regulator on my MPU9255 breakout board with a solder bridge. Hence I can feed it with VDD from my nRF52DK, and not 5V as it seems like you do.

RE: nrf52 with MPU9255

kirt — Fri, 09 Mar 2018 17:02:59 GMT

Yes,as mentioned earlier ,I have programmEd nrf52 dk with soft device s132 then loaded dk with example code.

Can you share your 52dk interfacing with mpu9255 diagram/image ?

RE: nrf52 with MPU9255

MartinBL — Fri, 09 Mar 2018 15:18:50 GMT

Hi,

Have you remembered to program the Softdevice?

Can you program the attached test.hex file. That contains the softdevice and the application and should work. If not there is something wrong with your HW or wiring.

devzone.nordicsemi.com/.../test.hex

RE: nrf52 with MPU9255

kirt — Fri, 09 Mar 2018 07:17:03 GMT

hi,

I tried with fresh code form github.i am not able to see accel values .but before getting values i should get MPU BLE device in nrf connect Application.But i dont see such device under 'SCANNER' option in nrf connect (downloaded from nordic website).

i am using default pins as given in example.I am connecting pins as shown in image.Please have a look and correct me if wrong .

I have programmed nrf52 with softdevice s132.I have checked supply for MPU9255 (5v w.r.t GND) as shown in image and its 5 V dc

RE: nrf52 with MPU9255

MartinBL — Thu, 08 Mar 2018 15:00:01 GMT

Hi,

Can you try download a fresh copy of the examples from github and try again: Please use the pin described in the example:

In nrf_drv_mpu_spi.c:

#define MPU_SPI_MISO_PIN    28 // MPU SDO. 'AD0' on MPU breakout board silk screen
#define MPU_SPI_MOSI_PIN    4  // MPU SDI. 'SDA' on MPU breakout board silk screen
#define MPU_SPI_SCL_PIN     3  // MPU SCLK. 'SCL' on MPU breakout board silk screen
#define MPU_SPI_CS_PIN      29 // MPU nCS. 'NCS' on MPU breakout board silk screen

In main.c

#define MPU_MPU_INT_PIN     30

And remember to program the Softdevice in addition to the application.

It should work straight out of the box. If it doesn't there must be something wrong with your kit, sensor, or wiring.

RE: nrf52 with MPU9255

kirt — Thu, 08 Mar 2018 07:20:34 GMT

hi ,

Default pins specified in nrf_drv_mpu_spi.c are pin 4,28,3,29.do I need to connect these 4 wires as shown in image

RE: nrf52 with MPU9255

kirt — Wed, 07 Mar 2018 12:36:03 GMT

yes,I tried with default pins.

i didnot get accel values.I even tried to print on jlink RTT viewer by giving some logs in main() function .but nothing printed on jlink RTT.

RE: nrf52 with MPU9255

kirt — Wed, 07 Mar 2018 09:48:57 GMT

Yes,I cant use pin 21.

which pins of nrf52 dk do i need to use defualt pins 4,28,3,29 given in nrf_drv_mpu_spi.c ?

RE: nrf52 with MPU9255

MartinBL — Tue, 06 Mar 2018 15:57:54 GMT

Then why did you post an image of the pin documentation for the PCA10056? The PCA10040 version on github should work out of the box. Have you tried the example with the default pins? You can't use pin 21 on the kit. Refer to the silkscreen below the kit to see why.

RE: nrf52 with MPU9255

kirt — Tue, 06 Mar 2018 13:43:38 GMT

Hi MartinBL,

I amnot using PCA 10056.I am using PCA10040.can you share link of updated git hub example

thank you

RE: nrf52 with MPU9255

MartinBL — Tue, 06 Mar 2018 13:20:53 GMT

Hi,

I have pushed an updated 'nrf5-ble-data-ready-interrupts' example to github that I have tested with a PCA10056 and an MPU9255.

Note that to use pin 17, 19, 20, and 21 on the PCA10056 you will need to cut some solder bridges and do some soldering as these pins are not actually connected to the P24 header on the kit by default (as is described in the image you have posted): Solder bridge configuration.

RE: nrf52 with MPU9255

kirt — Tue, 06 Mar 2018 10:59:33 GMT

hi,can you help on this .with the link you provided i m getting this error identifier " mpu_config_t " undefined.

RE: nrf52 with MPU9255

kirt — Tue, 06 Mar 2018 09:32:40 GMT

included,

one more error identifier " mpu_config_t " undefined

RE: nrf52 with MPU9255

karthikeyan — Tue, 06 Mar 2018 09:24:41 GMT

hi,

yes you can include it will work

RE: nrf52 with MPU9255

kirt — Tue, 06 Mar 2018 09:19:43 GMT

hi,tried with given link ,code shows errors as cannotopen source input file "app_mpu.h" ," ble_mpu.h", " mpu9255_register_map.h"

shall i include the same file given in here?

RE: nrf52 with MPU9255

karthikeyan — Tue, 06 Mar 2018 09:10:02 GMT

hi,

in the zip file go to pca10056.h file in there they have mentioned the pin numbers like this

check as per your needs

RE: nrf52 with MPU9255

kirt — Tue, 06 Mar 2018 08:57:45 GMT

hi,please confirm me with these mentioned pins which i am using for spi to interface with dk board.