This document is a collection of tips and best practices for developing on the nRF52 platform. It is designed to evolve continuously with the latest information, and contributions are welcome through pull requests on GitHub.
This is a mini-HOWTO on installing the appropriate firmware and adapter software, it is loosely based on [this tutorial by RAK](https://docs.rakwireless.com/Product-Categories/Accessories/RAKDAP1-Flash-and-Debug-Tool/Quickstart/#rak4600-evaluation-board).
The [RAKDAP1/NanoDAP](https://store.rakwireless.com/products/daplink-tool) is a very reasonably priced ($10) USB-based debugging probe. It can be used on many ARM targets but is particularly suited for the nRF52 CPUs. It seems to be based on the ARM [daplink](https://daplink.io/) [project](https://github.com/ARMmbed/DAPLink). The fork of this project is located here: [nanoDAP](https://github.com/wuxx/nanoDAP). The fork is fairly old with respect to the latest daplink goodness, but it seems fine.
If you are looking to buy a probe, there are many other daplink-based devices available. They are suspected to be mostly identical. If you find one that works well, please add a note to this document.
You'll need to install the [pyocd](https://pyocd.io/) application to allow VSCode to talk to the NanoDAP. You first install the tool itself but then must add the support files for the nrf52840:
If you are developing on a linux system, you will need to install the udev rules for the NanoDAP.
This is done by copying the rules file from the pyocd distribution to the udev rules directory [per these instructions](https://github.com/pyocd/pyOCD/tree/main/udev).
The Meshtastic project has a special build environment/target which has been configured to work with the NanoDAP. To use it select the "env:rak3631_dap" target via the command palette or in the bottom left of your VSCode/PlatformIO window. Once that target is selected it changes two things:
