# NRF51822 AQI Sensor Test Program

*** NOTE: THIS APPLICATION IS FOR _xxAC VERSION ONLY NOW, DUE TO LACK OF SRAM ***

## Work in progress:
- [x] LEDs and buttons
- [ ] Power management
- [x] FreeRTOS
- [x] BLE API
- [ ] Sensors

## How to compile?

* Edit `Makefile` and replace `SDK_ROOT` to your SDK installation directory.
* Run `make`

## How to flash?
* Use OpenOCD: 
```
openocd -f { YOUR_DEBUGGER_CONFIG } -f target/nrf51.cfg
```
* If you are not using ST-LINKV2 nor CMSIS-DAP, try the following:
```
openocd { YOUR_DEBUGGER_CONFIG } -c 'set WORKAREASIZE 0' -f target/nrf51.cfg
```
Due to incompatible flash algorithm issue.

## What if...?

* My device is an _xxAC device(with 32KB RAM):
    * Replace linker script with `nrf51_xxac.ld` and re-compile.
    * Do nothing, if the program compiles for 16KB variant, it will run on 32KB devices without any problems.
* Hardfault when using logger API:
    * Blame Nordic, they don't know how to write reentrant code.
    * Use SEGGER RTT logger API.

## Boards supported:
* Waveshare BLE-400 board, w/ NRF51822 module
* Some strange AQI sensor board.

## DFU support:
Currently there are **NO** DFU methods, **DO NOT** flash it without a debugger.