Improved documentation readability by rephrasing confusing sentences. Added Sitronix ST7789V datasheet link to SPI-LCD-driver.md for easier reference.
2.3 KiB
Build a stub for PineTime using NRF52-DK
NRF52-DK is the official developpment kit for the NRF52832 SoC from Nordic Semiconductor used in the PineTime.
This development kit can be very useful for PineTime development:
- You can use its embedded JLink SWD programmer/debugger to program and debug your code on the PineTime
- As it's based on the same SoC than the PineTime, you can program it to actually run the same code as the PineTime.
This page is about the 2nd point : we will build a stub that will allow us to run the same code you can run on the PineTime. This will allow you to work more easily if you don't have a PineTime dev kit around, if you don't want to modify your dev kit for SWD programming, or if you want to use some feature from the NRF52-DK (like power measurement).
This stub only implements the display, the button and the BLE radio. The other features from the pintime are missing:
- heart rate sensor
- SPI flash
- touchpad
- accelerometer
These devices could be added on this stub, but I do not have the parts to try them out for now.
Here are the parts you need to build this simulator:
- NRF52-DK
- An ST7889 display (I bought this one)
- A push-button (the one I use comes from a previous project build around ESP8266 board Wemos D1 Mini).
- Dupont wires
You just need to make the following connections:
NRF52-DK | ST7889 display |
---|---|
VDD | VCC |
GND | GND |
P0.03 | SDA |
P0.26 | RES |
P0.02 | SCL |
P0.18 | DC |
NRF52-DK | Push Button |
---|---|
P0.13 | Button IN (D3 in my case) |
GND | GND |
You also need to enable the I/O expander to disconnect pins from the buttons and LED on the NRF52-DK and leave them available on the pin headers:
NRF52 -DK | NRF52- DK |
---|---|
DETECT | GND |
Now, you should be able to program the SoC on the NRF52-DK board, and use it as if it was running on the PineTime.