IMU for nRF52840 to use in parallel with UWB

RE: IMU for nRF52840 to use in parallel with UWB

ayaroshlvua — Mon, 25 Mar 2024 19:03:09 GMT

Thank you a lot for your responses and the documents you provided, this really helps. I will search for some solutions and maybe post here if anyone is also researching this question.

RE: IMU for nRF52840 to use in parallel with UWB

hmolesworth — Mon, 25 Mar 2024 17:33:31 GMT

Yes, quite so. Be aware though that some pins are already connected on the DK, such as P0.00 and P0.01 to the 32.768kHz crystal. Download the nRF52840DK Hardware Reference documents to get the schematic and search the schematic pdf for usage of the pins you expect to use.

nrf52840-development-kit---hardware-files-3_0_0

Older versions here nRF52840-DK

RE: IMU for nRF52840 to use in parallel with UWB

ayaroshlvua — Mon, 25 Mar 2024 16:56:00 GMT

Thank you very much! So I basically can search for IMUs that support SPI connection and connect it to pins P0.28, P0,29, P0.30 and P0.31 on the nRF52840 DK?

And yes, IMU doesn't need to be attached to UWB shield, so if I understand correctly, I can also use, for example, pins P0.00-P0.10 on the DK?

Thanks again!

RE: IMU for nRF52840 to use in parallel with UWB

hmolesworth — Mon, 25 Mar 2024 16:50:59 GMT

You can probably use A2, A3, A4, A5, which appear to be unused pins on the shield, for the second SPI port :

These connect to P0.28, P0,29, P0.30 and P0.31 on the nRF52840 DK;

DWM3000EVB documents

Other free pins on the DK can also be used if the second device doesn't physically need to be on the shield.

RE: IMU for nRF52840 to use in parallel with UWB

ayaroshlvua — Mon, 25 Mar 2024 15:43:49 GMT

Hello, Edvin. Thanks a lot for your reply.
The problem is I don’t know much about connection interfaces, and I can’t really try connecting IMU, because I don’t have it. So the point of my question is to figure out whether it’s possible to use nRF52840 with UWB and IMU at all, and if yes, what type of IMU should I purchase.
The UWB device (DWM3000EVB) is connected via Arduino-compatible shield (at least they call it so). It would be very kind of you if you can help me to figure out what GPIOs are left after UWB connection, and whether it is possible to connect IMU using them at all. And if it’s possible, I would greatly appreciate if you can suggest me some IMUs that support this kind of connection and can be used in such setup. I attached the photo of the board with UWB connected to it so you can understand what’s going on.
Thanks in advance!

RE: IMU for nRF52840 to use in parallel with UWB

Edvin — Mon, 25 Mar 2024 14:52:42 GMT

Hello,

The nRF52 is very flexible. However I can't say that I ever tested the shield that you linked to, and I don't know much about the UWB device. But I imagine it only uses one instance of SPI or I2C. So whatever is not used, you can use for your IMU. Whether you still have access to those GPIOs after connecting the shield, I don't know. I don't know whether those are passthrough (the gpios that aren't actually used by the shield)? Are they?

I suggest you just try. Connect whatever peripheral you want to use with the nRF52 to the IMU, and get it working without the shield first. After that, try adding the shield and see if you still can make it run. Try to use the GPIOs that are not actively used by the shield, though.

Best regards,

Edvin