# Connecting Zehnder Comfoair Q with M5Stack Atoms3 Lite + Mini CAN Unit

Before you start, make sure you have already flashed the firmware on the ESP32 board. If you haven't done that yet, please follow the instructions in the [README](../README.md).

## Components

- [M5Stack Atoms3 Lite ESP32S3](https://docs.m5stack.com/en/core/AtomS3%20Lite)
- [M5Stack Mini CAN Unit (TJA1051T/3)](https://docs.m5stack.com/en/unit/Unit-Mini%20CAN)
- 4-pin grove cable to connect Mini CAN with AtomS3 (included with the Mini CAN unit)
- 4x male-male Dupont jumper cables (example uses the [24AWG 4-CORE Shielded Cable](https://docs.m5stack.com/en/accessory/cable/24awg_cable))
- USB-C cable to connect the board to your computer

## How

1. Connect the Dupont jumper cables to the Zehnder ventilation unit (see diagram below).
![Zehnder CAN connection with jumper cables](./m5stack-atoms3-1.jpg)
2. Connect the other side of the Dupont jumper cables with Mini CAN unit (see diagram below). Make sure you connect the cables correctly.
![Mini CAN unit connection with jumper cables](./m5stack-atoms3-2.jpg)
1. Connect the Mini CAN unit with the M5Stack Atoms3 Lite board using the 4-pin grove cable.

Here is a picture of the finished setup:
![AtomS3 Lite + Mini CAN connected to Zehnder ComfoAir Q](./m5stack-atoms3-3.jpg)


### Connection diagram

```

|-----------------+                                    +-------------+
|                 |     +----------------------+       |             |
|   [ComfoAir]    |     |       [MiniCan]      |       |  [ESP32S3]  |
|                 |     |     [TJA1051T/3]     | Grove |             |
| (red)       12V o-----o HV               RXD o=======o GPIO1       |
| (black)     GND o-----o GND              TXD o=======o GPIO2       |
| (white)   CAN_L o-----o CAN_L             5V o=======o 5V          |
| (yellow)  CAN_H o-----o CAN_H            GND o=======o GND         |
|                 |     |                      |       |             |
|-----------------+     +----------------------+       +-------------+
```