Homebridge-PhormalabDimmer

Homebridge accessory plugin for Phormalab infrared lamps that are connected to an I²C-capable device like a Raspberry Pi connected to an I²C-compatible MCP4728 DAC. This in turn, will provide input into a proportional output solid state relay. If you wanted to repurpose the code here to run dimmable/proportional output from the MCP4728, should be easy to do. Code only allows for 4 devices.

Features

• Control the infrared heat output from a lamp via HomeKit dimmer function
• Setup automations in HomeKit
• Ask Siri to control your devices

Setup / Installation

1. Install Homebridge
2. npm install homebridge-phormalabdimmer
3. Edit config.json and configure accessory. See Configuration section.
4. Start Homebridge

Configuration

To configure the plugin, add the following to the accessories section in config.json of Homebridge. The i2c_address is assumed to be default for MCP4728 (0x60) on the default I²C bus (/dev/i2c-1). If you need to specify a different address or bus, use "i2c_address": "0x.." and "i2c_device": "/dev/i2c-..". The lamp_names are assumed to be in same order as corresponding MCP4728 output connections (0–3 or labeled A–D on some boards).

    "platforms": [
        {
            "name": "Phormalab Dimmer",
            "platform": "PhormalabDimmer",
            "lamp_names": [
                "Phormalab South",
                "Phormalab South Middle",
                "Phormalab North Middle",
                "Phormalab North"
            ]
        }
    ]

Help

If you have any questions or help please open an issue on the GitHub project page.

Setup photos

Build list

If you are interested in building something similar, here is a link to all the various items I used to build. This was a fun project.

• (1) Raspberry Pi 4b+
• (1) Tall 2✕20 and 2✕2 stacking headers for Pi
  • This allows you to use PoE hat + have 2✕20 pins pass through for use by PermaProto HAT below (requires soldering)
• (1) Raspberry Pi PoE Hat
• (1) Adafruit PermaProto HAT
• (2) 10-pin terminal blocks
• (2) 4-pin terminal blocks
• (1) 2-pin terminal block
• (1) MCP4728 DAC with 4✕0-5v outputs
• (1) C4 Labs Zebra VESA Pi Mount
  • Drilled holes in cover of the Wiegmann enclosure to mount inside.
  • Excess low-voltage wiring added to allow for easy access when opened
• (1) M2.5 Hex Standoff Kit
• (4) Crydom PMP2425W Solid State Proportional Relay
• (2) Crydom HS053 Heat Sink for SSRs
  • Orient fins vertically to allow for appropriate air flow
• (4) Crydom HK8 Mounting kit for PM22 Series SSRs
• (4) Crydom HSP-7 Thermal Pad for PM22 Series SSRs
• (1) McMaster-Carr 16" ✕ 12" ✕ 8" Enclosure
  • Place heat sinks + solid state relays + temperature sensor here, fan added to ensure temperature stays below
• (1) Wiegmann 6" ✕ 6" ✕ 4" Enclosure
  • Where I mounted the PoE-powered Pi
• (1) SHT31 I²C Temperature & Humidity Sensor
  • Use with homebridge-sht3x plugin
• (1) Stego FPO 120v 92 ✕ 92 mm fan
  • Use angle grinder to cut holes in the McMaster enclosure for fans
• (1) Stego FPO 92 ✕ 92 mm intake filter
• (1) Stego ST 011 normally open thermostat to control fan
  • Set at 85˚F/29˚C to turn on when temperature in box reaches this to cool enclosure

Changelog

1.0.0

• Initial version

License

The project is subject to the MIT license unless otherwise noted. A copy can be found in the root directory of the project LICENSE.