brewbot
A coffee brewing Slack notification system using a non-invasive current sensor and Raspberry Pi. The setup watches energy consumption and waits for a rise in current draw above 7A, followed by several minutes of sustained usage. Once the time threshold has passed, it does an HTTP POST to a Slack webhook, sleeps for about 15 minutes, then starts monitoring again.
Parts List
- MCP3008 8-Channel 10-Bit Analog to Digital Converter
- Raspberry Pi model B
- 16-pin IC socket
- Assortment of heat shrink tubing
- Panel mount to Micro USB adapter
- 10KΩ 1/4W LED resistor
- Half-size Perma-Proto Raspberry Pi Breadboard PCB Kit
- 5mm Yellow LED
- 1/8" panel mount audio jack
- 10uF electrolytic decoupling capacitor
- 33Ω 1/2W burden resistor
- 2x 470KΩ 1/2W voltage divider resistors
- 30A non-invasive current sensor
- 22 AWG Solid Core Hook Up Wire
- 5x7 photo box, from The Container Store
- 8 GB Class 10 SDHC card
- Edimax EW-7811Un Wireless Nano USB Adapter
- 6x Nylon screws washers and nuts
- 8" AC Cord Clips
- HDMI to Mini HDMI adapter
- 6' Mini HDMI to HDMI Cable
- 10' USB A Male to B Male Cable
Connections
While I don't have a schematic handy, the gist of the connections is running the CT sensor to an analog input on the MCP3008 chip (See: How to build an Arduino energy monitor), then wiring the digital SPI output of the MCP3008 to Raspberry Pi GPIO pins. Adafruit has a guide on connecting the MCP3008 to a Raspberry Pi that was useful.