A WebApp running on a Raspberry Pi calls a C++ Script to collect data from the sensors near the plant. This script, quiered with what data to collect, communicates via radio to an Arduino Pro Mini. The Arduino then collects data, like temperature, light intensity and soil moisture levels, and sends it back to the Raspberry Pi. The C++ script then updates an SQLite3 database with the timestamped data.
In order to use software defined SPI pins, since one of my Arduino Pro Mini's SPI pins were blown, follow the directions here.
Download the DIgitalIO library and uncomment the #define SOFTSPI line in RF24_config.h. I defined the pins as such:
SOFT_SPI_MISO_PIN |
9 |
SOFT_SPI_MOSI_PIN |
8 |
SOFT_SPI_SCK_PIN |
7 |
I connected the Arduino Pro Mini to the nRF24L01+ like so:
| RF Module | Pin Name | Arduino Pin |
|---|---|---|
| 1 | GND | GND |
| 2 | VCC (+3.3V) | ACC |
| 3 | CE | 2 |
| 4 | CSN | 3 |
| 5 | SCK | 7 |
| 6 | MOSI | 8 |
| 7 | MISO | 9 |
| 8 | IRQ |
View sensor documentation here.
For various set up instructions on Linux with C++, check the RF24 Documentation and SQLite3.
I connected the raspberry pi to the nRF unit like so (pinout available here or here):
| RF Module | Pin Name | RPI Pin | RPI Pin Name |
|---|---|---|---|
| 1 | GND | 25 | rpi-gnd |
| 2 | VCC (+3.3V) | 17 | rpi-3v3 |
| 3 | CE | 15 | rpi-gpio22 |
| 4 | CSN | 24 | rpi-gpio8 |
| 5 | SCK | 23 | rpi-sckl |
| 6 | MOSI | 19 | rpi-mosi |
| 7 | MISO | 21 | rpi-miso |
| 8 | IRQ |