(Re)store remote management of Gen2 Nest Thermostat through your existing Home Assistant setup.

This project aims to provide a completely new UI for a rooted Gen 2 Nest Thermostat.

• Bi-directional Home Assistant connection using esphome API
• Automatic device discovery in Home Assistant (mDNS)
• Dial interface similar to stock Nest UI with mode select
• Away mode based on presence sensors
• Turning the HVAC system on/off to reach target temp.
• Configurable interface look/feel (separate from app config)
• Configuration file for settings such as:
  • HA related parameters (api key, device name, etc)
  • Wifi network settings
  • Screen brightness, auto-off timeout
  • HVAC wiring settings
• Integrate with system wifi manager (Connman 1.29)
• Screen auto-off, wake on user input

Run cargo run to start retherm in a simulated window (uses SDL, which needs to be installed). Some device specific features don't work in this mode.

Add target with rustup

rustup target add armv7-unknown-linux-gnueabihf

Get toolchain from https://github.com/eckucukoglu/arm-linux-gnueabihf and add to PATH.

export PATH=~/Toolchains/arm-linux-gnueabihf/bin:$PATH

Create ~/.cargo/config.toml with linker command from toolchain.

[target.armv7-unknown-linux-gnueabihf]
linker = "arm-linux-gnueabihf-gcc"

First; the stock app needs to be stopped.

/etc/init.d/nestlabs stop

Optional: start build_recv.sh on device and use build_push.sh to build, push to device, and restart app (uses netcat on port 51234).

./build_push.sh

Or build and send manually.

# Build output at `target/armv7-unknown-linux-gnueabihf/release/retherm`
cargo build --no-default-features --features device --target=armv7-unknown-linux-gnueabihf

• Fancy animations for screen transtions
• Extensible list of screens through configuration
  • Possible use case would be controlling other HA devices through some sort of configurable menu system
  • Example: Screen for turning on/off other devices

I'm not sure how important this is since the Nest is always powered. But I can see how getting the most out of the battery in the event of a power outage could be important.

This is the behaviour I've observed with the stock Nest app.

• I'm assuming that when the device can no longer be pinged, it has gone into some sort of sleep mode
• Waking the screen screen causes network reconnect
• With the display connected to USB for power, it usually remains network accessible for some time after the screen turns off, but it will eventually stop responding to ping
• With display disconnected from power, it disconnects from network soon after display turns off (I have not timed how long it remains accessible)
  • However, if you happen to open an SSH session befor the screen turns off, the session will remain active for a while (few minutes at most)
  • SSH session hangs, it doesn't disconnnect
  • If you are quick about it, you can wake the display and resume a hung session
  • If it hangs too long, waking device doesn't help, session remains hung
• When the stock app is stopped, and the display is not connected to power, the device seems to remain network accessible for much longer (presummably until battery dies)
• Need to look into what Nest app does; could it be as simple setting kernel power state?