jukkas / ble-nrf24-es-tlm

Bluetooth Low Energy (BLE) Eddystone beacon using STM8 and nRF24L01+

Bluetooth Low Energy (BLE) Eddystone beacon using STM8 and nRF24L01+

This demo code implements one of the cheapest possible ways to implement a BLE beacon.

It uses low-cost nRF24L01-module for BLE compatible radio and STM8 development module as a microcontroller.

Idea for abusing NRFL01 originates from http://dmitry.gr/?r=05.Projects&proj=11.%20Bluetooth%20LE%20fakery (including related code).

Idea to use that for Eddystone URL-beacon, and some related code, I found from https://github.com/kasparsd/tinystone .

This implementation adds related STM8 code and also support for interleaved Eddystone telemetry (TLM) frames containing temperature data, which can be read from attached DS18B20 sensor.

Git branch 'temperature-beacon' contains version that broadcasts only temperature data without any Eddystone data.

A blog post about all this...

Hardware used

This example assumes following hardware configuration:

• STM8 development board based on STM8S103F3.

  I am using the really cheap Chinese STM8S103F3P6 based minimal development board available from Ebay/Aliexpress ("STM8 Minimum System Development Board Module").

• ST-LINK/V2 programmer

• nRF24L01+ module

  Connect PINs:

  CSN <-> A3
  CE <-> D2
  SCK <-> C5
  MOSI <-> C6
  MISO <-> C7
  

• Optionally for TLM temperature: DS18B20-sensor.

  See https://github.com/jukkas/stm8-sdcc-examples/tree/master/ds18b20 . Except DS18B20 data pin is B4.

Software/development environment

• Linux
• SDCC compiler
• stm8flash for flashing the board. https://github.com/vdudouyt/stm8flash

Notes

BLE address that this implementation broadcasts is staticly defined in code. So if you have multiple devices, change the address in code to be unique for each device.

Copyrights

Some of the NRF24 BLE code is copied/adapted from https://github.com/kasparsd/tinystone/blob/master/main.c , which in turn has copied from http://dmitry.gr/?r=05.Projects&proj=11.%20Bluetooth%20LE%20fakery , which says:

"All the code as well as the research that went into this and is published here is under this license: you may use it in any way you please if and only if it is for non-commercial purposes, you must provide a link to this page as well. Any commercial use must be discussed with me." (http://dmitry.gr/)

All other written by me is public domain. No guarantees etc. Use at your own risk.