Hardware:
- The necessary components for the MSP430 to be operational are quite simple: only a CR2032 battery for power, two decoupling capacitors, a pull-up resistance on the RST pin. Note some pins connected to TX, TEST, RST and GND have been soldered in order to facilitate the programming and debugging of the MSP430.
- The cluster in the top left corner are the LDR in a potential divider with the 10k resistors and the TMP36 temperature sensor: light levels are then directly read with the pins analogue A0, A1, A3 from the MSP430, and the temperature from A4.
- The rest is just a lot of wires to connect the MSP430 to the transmitter NRF24L01, the colour code is used to facilitate the wiring (sorry for brown --> GND but black looked messy)
Software:
On the software side, the micro first convert the analog read from the temperature sensor to celsius degrees. Then combined with the light sensors, they determine the level of coffee: full, half, low or empty. Finally the temperature and the coffee level is sent to the receiver to be uploaded on the web.
The coffee jug transmitter circuit is implemented on a stripped board:
Messy Middle man NRF24l01 to ESP8226:
Level of coffee followed by its temperature:
what are you using to stick the photoresistors on there?