The project comprises hardware and firmware.
The firmware runs on a low power MSP430 microcontroller. It periodically reads temperature and humidity from an HDC2022 sensor. Readings are base-64 encoded and stored in a URL, which resides on an NFC EEPROM.
When a phone is hovered over a cuplTag, the URL is read and a web browser opens (demo). No app is required. The web application decodes, timestamps and displays readings to the user.
- Average current consumption ~0.5uA. Runs for years on a CR1220 battery.
- Ease of use. No app to install on the Android / Apple phone.
- Data are automatically uploaded to the web.
J30 is a 2.54mm pitch 2x4 way header.
| Pin | Name | Direction | Description | Note |
|---|---|---|---|---|
| 1 | TX | Output | UART transmit | Transmit from MSP430 |
| 2 | RX | Input | UART receive | Receive to MSP430 |
| 3 | GND | GND | ||
| 4 | TST | Input | Spy-Bi-Wire Clock | Also TEST signal for BSL entry |
| 5 | GND | GND | ||
| 6 | nRST | I/O | Spy-Bi-Wire Data | Also active low RESET signal |
| 7 | VDD | Input | Power in | +3V3 |
| 8 | nPRG | Input | Prog. Mode Enable | Active low |
- Getting Started by loading the project into Code Composer.
- Programming the MSP430.
- Configuration with UART (1 of 2).
- Configuration with UART (2 of 2) [cuplfrontend].
- Configuration with NFC.
- Configuration Strings that can be written over the serial port or NFC.
CERN Open Hardware Licence Version 2 - Strongly Reciprocal
