nodemcu-firmware/docs/modules/can.md

# CAN Module
| Since  | Origin / Contributor  | Maintainer  | Source  |
| :----- | :-------------------- | :---------- | :------ |
| 2017-04-27 | [@ThomasBarth](https://github.com/ThomasBarth/ESP32-CAN-Driver/), zelll | | [can.c](../../components/modules/can.c)|

The CAN module provides access to the in-built CAN controller.


## can.send()
Send a frame.

#### Syntax
`can.send(format, msg_id, data)`

#### Parameters
- `format` Frame format. `can.STANDARD_FRAME` or `can.EXTENDED_FRAME`
- `msg_id` CAN Messge ID
- `data` CAN data, up to 8 bytes
  
#### Returns
`nil`


## can.setup()
Configuration CAN controller.

#### Syntax
`can.setup(config, callback)`

#### Parameters
- `config` table.
    - `speed` kbps. One of following value: `1000`, `800`, `500`, `250`, `100`.
    - `tx` Pin num for TX.
    - `rx` Pin num for RX.
    - `dual_filter` `true` dual filter mode, `false` single filter mode (default)
    - `code` 4-bytes integer. Use this with mask to filter CAN frame. Default: `0`. See [SJA1000](http://www.nxp.com/documents/data_sheet/SJA1000.pdf)
    - `mask` 4-bytes integer. Default: `0xffffffff`
- `callback` function to be called when CAN data received.
    - `format` Frame format. `can.STANDARD_FRAME` or `can.EXTENDED_FRAME`
    - `msg_id` CAN Message ID
    - `data` CAN data, up to 8 bytes
  
#### Returns
`nil`

#### Example
```lua
can.setup({
  speed = 1000,
  tx = 5,
  rx = 4,
  dual_filter = false,
  code = 0,
  mask = 0xffffffff
}, function(format, msg_id, data) end)
```

## can.start()
Start CAN controller.

#### Syntax
`can.start()`

#### Parameters
none

#### Returns
`nil`


## can.stop()
Stop CAN controller.

#### Syntax
`can.stop()`

#### Parameters
none

#### Returns
`nil`