nRF7002DK Fitness Tracker using MMA7361 Accelerometer and GC9A01 driven round LCD display

[Krapic]

Hello,

I'm currently working on a fitness tracker application using the Nordic nRF7002 DK board, paired with an analog MMA7361 accelerometer, and a round GC9A01 SPI-based LCD display.

I'm facing some challenges with properly integrating these components and ensuring compatibility within the nRF Connect SDK (Zephyr) environment. Specifically, I'd appreciate if you could provide guidance on:

1. Hardware Integration:

   • Recommended connection pins and guidelines for interfacing the MMA7361 analog outputs with the built-in ADC on the nRF7002 DK.

   • Recommended wiring and SPI pin assignments for integrating the GC9A01 display with nRF7002 DK.

2. Software Integration:

   • Recommended Zephyr drivers/modules for efficiently reading analog accelerometer data (via SAADC).

   • Recommended libraries or driver implementations compatible with Zephyr for controlling a GC9A01 LCD (or examples of similar displays).

   • Tips on effectively managing simultaneous SPI and ADC operations within Zephyr RTOS.

3. Sample Code/References:

   • Could you point me to existing Zephyr or nRF Connect SDK examples or projects that demonstrate similar integration (analog sensor + SPI display)?

Any additional insights, recommended best practices, or reference materials would be greatly appreciated.

Thank you in advance!

[Edvin]

Hello,

For the display, perhaps you can test the sample:

NCS\zephyr\samples\subsys\display\cfb

But you need to specify the display you are using using devicetree. You should be able to build this sample for the "reel_board", which has a display. You can look at the reel_board devicetree files located in:

NCS\zephyr\boards\phytec\reel_board\reel_board.dts.

You can add something like this to a file called nrf5340dk_nrf5340_cpuapp.overlay in your application's main folder, and any parts that you copy from the zephyr\boards\nordic\nrf5340dk\nrf5340dk_nrf5340_cpuapp.dts and paste in your overlay file, and then change there will overwrite what it says in the original .dts file.

As for SPI and ADC, I would recommend that you check out the Developer Academy. Both the nRF Connect SDK Fundamentals and Intermediate courses are relevant. The intermediate course even has a lesson dedicated to the PWM, SPI and ADC peripherals.

Best regards,

Edvin