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fix i2c doc

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devsaurus 2017-03-02 21:47:22 +01:00
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docs/en/modules/i2c.md
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@ -4,6 +4,7 @@
| 2014-12-22 | [Zeroday](https://github.com/funshine) | [Zeroday](https://github.com/funshine) | [i2c.c](../../../app/modules/i2c.c)| | 2014-12-22 | [Zeroday](https://github.com/funshine) | [Zeroday](https://github.com/funshine) | [i2c.c](../../../app/modules/i2c.c)|
This module supports different interfaces for communicating via I²C protocol. All interfaces can be assigned to arbitrary GPIOs for SCL and SDA and can be operated concurrently. This module supports different interfaces for communicating via I²C protocol. All interfaces can be assigned to arbitrary GPIOs for SCL and SDA and can be operated concurrently.
- `i2c.SW` software based bitbanging, master mode only, synchronous operation - `i2c.SW` software based bitbanging, master mode only, synchronous operation
- `i2c.HW0` ESP32 hardware port 0, master or slave mode, synchronous or asynchronous operation - `i2c.HW0` ESP32 hardware port 0, master or slave mode, synchronous or asynchronous operation
- `i2c.HW1` ESP32 hardware port 1, master or slave mode, synchronous or asynchronous operation - `i2c.HW1` ESP32 hardware port 1, master or slave mode, synchronous or asynchronous operation
@ -11,7 +12,7 @@ This module supports different interfaces for communicating via I²C protocol. A
The hardware master interfaces differ from the SW interface as the commands (start, stop, read, write) are queued up to an internal command list. Actual I²C communication is initiated afterwards using the `i2c.transfer()` function. Commands for the `i2c.SW` interface are immediately effective on the I²C bus and read data is also instantly available. The hardware master interfaces differ from the SW interface as the commands (start, stop, read, write) are queued up to an internal command list. Actual I²C communication is initiated afterwards using the `i2c.transfer()` function. Commands for the `i2c.SW` interface are immediately effective on the I²C bus and read data is also instantly available.
## i2c.address() ## i2c.address()
Send (`i2c.SW`) or queue (`i2c.HWx`) I²C address and read/write mode for the next transfer. Send (`SW`) or queue (`HWx`) I²C address and read/write mode for the next transfer.
Communication stops when the slave answers with NACK to the address byte. This can be avoided with parameter `ack_check_en` on `false`. Communication stops when the slave answers with NACK to the address byte. This can be avoided with parameter `ack_check_en` on `false`.
@ -31,7 +32,7 @@ Communication stops when the slave answers with NACK to the address byte. This c
[i2c.read()](#i2cread) [i2c.read()](#i2cread)
## i2c.read() ## i2c.read()
Read (`i2c.SW`) or queue (`i2c.HWx`) data for variable number of bytes. Read (`SW`) or queue (`HWx`) data for variable number of bytes.
#### Syntax #### Syntax
`i2c.read(id, len)` `i2c.read(id, len)`
@ -96,7 +97,7 @@ Initialize the I²C interface for master mode.
[i2c.read()](#i2cread) [i2c.read()](#i2cread)
## i2c.start() ## i2c.start()
Send (`i2c.SW`) or queue (`i2c.HWx`) an I²C start condition. Send (`SW`) or queue (`HWx`) an I²C start condition.
#### Syntax #### Syntax
`i2c.start(id)` `i2c.start(id)`
@ -111,7 +112,7 @@ Send (`i2c.SW`) or queue (`i2c.HWx`) an I²C start condition.
[i2c.read()](#i2cread) [i2c.read()](#i2cread)
## i2c.stop() ## i2c.stop()
Send (`i2c.SW`) or queue (`i2c.HWx`) an I²C stop condition. Send (`SW`) or queue (`HWx`) an I²C stop condition.
#### Syntax #### Syntax
`i2c.stop(id)` `i2c.stop(id)`
@ -143,7 +144,7 @@ First argument to the callback is the error code (0 = no error), followed by a s
- `nil` for asynchronous operation - `nil` for asynchronous operation
## i2c.write() ## i2c.write()
Write (`i2c.SW`) or queue (`i2c.HWx`) data to I²C bus. Data items can be multiple numbers, strings or lua tables. Write (`SW`) or queue (`HWx`) data to I²C bus. Data items can be multiple numbers, strings or lua tables.
Communication stops when the slave answers with NACK to a written byte. This can be avoided with parameter `ack_check_en` on `false`. Communication stops when the slave answers with NACK to a written byte. This can be avoided with parameter `ack_check_en` on `false`.
@ -173,12 +174,12 @@ The I²C slave mode is only available for the hardware interfaces `i2c.HW0` and
Registers or unregisters an event callback handler. Registers or unregisters an event callback handler.
#### Syntax #### Syntax
`i2c.slave.on(id, event[, cb_fn]) `i2c.slave.on(id, event[, cb_fn])`
#### Parameters #### Parameters
- `id` interface id, `i2c.HW0` or `i2c.HW1` - `id` interface id, `i2c.HW0` or `i2c.HW1`
- `event` one of - `event` one of
- "receive" data received from master - "receive" data received from master
- `cb_fn(err, data)` function to be called when data was received from the master. Unregisters previous callback for `event` when omitted. - `cb_fn(err, data)` function to be called when data was received from the master. Unregisters previous callback for `event` when omitted.
#### Returns #### Returns
@ -188,17 +189,17 @@ Registers or unregisters an event callback handler.
Initialize the I²C interface for slave mode. Initialize the I²C interface for slave mode.
#### Syntax #### Syntax
`i2c.slave.setup(id, slave_config) `i2c.slave.setup(id, slave_config)`
#### Parameters #### Parameters
- `id` interface id, `i2c.HW0` or `i2c.HW1` - `id` interface id, `i2c.HW0` or `i2c.HW1`
- `slave_config` table containing slave configuration information - `slave_config` table containing slave configuration information
- `sda` 0~33, IO index - `sda` 0~33, IO index
- `scl` 0-33, IO index - `scl` 0-33, IO index
- `addr` slave address (7bit or 10bit) - `addr` slave address (7bit or 10bit)
- `10bit` enable 10bit addressing with `true`, use 7bit with `false` (optional, defaults to `false` is omitted) - `10bit` enable 10bit addressing with `true`, use 7bit with `false` (optional, defaults to `false` is omitted)
- `rxbuf_len` length of receive buffer (optional, defaults to 128 if omitted) - `rxbuf_len` length of receive buffer (optional, defaults to 128 if omitted)
- `txbuf_len` length of transmit buffer (optional, defaults to 128 if omitted) - `txbuf_len` length of transmit buffer (optional, defaults to 128 if omitted)
#### Returns #### Returns
`nil` `nil`