A Node-RED node to read from the MCP3008 Analogue to Digital Converter, such as the Rasp.io analogzero, though it will work with breadboard versions also.
Warning: Input voltages must not exceed 3.3V
You must ensure that SPI is enabled. For recent (2016) versions of Raspbian you can do this
- Run
sudo raspi-config - Select
9 - Advanced Options - Select
A5 - SPI - Select
yesto enable SPI - Select
OKto confirm - Select the
Finishbutton
Run the following command in your Node-RED user directory - typically ~/.node-red
npm install node-red-node-pi-mcp3008
### Usage
Reads from an MCP3008 Analogue to Digital (ADC) chip on the Pi SPI CE0 connection.
You can either set a channel in the edit dialogue, or you can set the msg.payload to
select the channel dynamically. If so then the payload must be a value from 0 to 7.
Outputs a numeric msg.payload with a range of 0 to 1023, where 0 = 0V and 1023 = 3.3V (assuming you use the default 3.3V voltage reference).
Hint: use a range node to adjust the values to the range you want.
Also sets msg.topic to adc/{the pin number}