transferred i2c module

docs/en/modules/i2c.md

@@ -0,0 +1,130 @@
+# i2c Module
+
+## i2c.address()
+Setup I²C address and read/write mode for the next transfer.
+
+#### Syntax
+`i2c.address(id, device_addr, direction)`
+
+#### Parameters
+- `id` always 0
+- `device_addr` device address
+- `direction` `i2c.TRANSMITTER` for writing mode , `i2c. RECEIVER` for reading mode
+
+#### Returns
+`true` if ack received, `false` if no ack received.
+
+#### See also
+[i2c.read()](#i2cread)
+
+## i2c.read()
+Read data for variable number of bytes.
+
+#### Syntax
+`i2c.read(id, len)`
+
+#### Parameters
+- `id` always 0
+- `len` number of data bytes
+
+#### Returns
+`string` of received data
+
+#### Example
+```lua
+id  = 0
+sda = 1
+scl = 2
+
+-- initialize i2c, set pin1 as sda, set pin2 as scl
+i2c.setup(id, sda, scl, i2c.SLOW)
+
+-- user defined function: read from reg_addr content of dev_addr
+function read_reg(dev_addr, reg_addr)
+    i2c.start(id)
+    i2c.address(id, dev_addr, i2c.TRANSMITTER)
+    i2c.write(id, reg_addr)
+    i2c.stop(id)
+    i2c.start(id)
+    i2c.address(id, dev_addr, i2c.RECEIVER)
+    c = i2c.read(id, 1)
+    i2c.stop(id)
+    return c
+end
+
+-- get content of register 0xAA of device 0x77
+reg = read_reg(0x77, 0xAA)
+print(string.byte(reg))
+```
+
+####See also
+[i2c.write()](#i2cwrite)
+
+## i2c.setup()
+Initialize the I²C module.
+
+#### Syntax
+`i2c.setup(id, pinSDA, pinSCL, speed)`
+
+####Parameters
+- `id` always 0
+- `pinSDA` 1~12, IO index
+- `pinSCL` 1~12, IO index
+- `speed` only `i2c.SLOW` supported
+
+#### Returns
+`speed` the selected speed
+
+####See also
+[i2c.read()](#i2cread)
+
+## i2c.start()
+Send an I²C start condition.
+
+#### Syntax
+`i2c.start(id)`
+
+#### Parameters
+`id` always 0
+
+#### Returns
+`nil`
+
+####See also
+[i2c.read()](#i2cread)
+
+## i2c.stop()
+Send an I²C stop condition.
+
+#### Syntax
+`i2c.stop(id)`
+
+####Parameters
+`id` always 0
+
+#### Returns
+`nil`
+
+####See also
+[i2c.read()](#i2cread)
+
+## i2c.write()
+Write data to I²C bus. Data items can be multiple numbers, strings or lua tables.
+
+####Syntax
+`i2c.write(id, data1[, data2[, ..., datan]])`
+
+####Parameters
+- `id` always 0
+- `data` data can be numbers, string or lua table.
+
+#### Returns
+`number` number of bytes written
+
+#### Example
+```lua
+i2c.write(0, "hello", "world")
+```
+
+#### See also
+[i2c.read()](#i2cread)

mkdocs.yml

@@ -36,6 +36,7 @@ pages:
         - 'gpio': 'en/modules/gpio.md'
         - 'node': 'en/modules/node.md'
         - 'file': 'en/modules/file.md'
+        - 'i2c' : 'en/modules/i2c.md'
         - 'rtcmem': 'en/modules/rtcmem.md'
         - 'rtctime': 'en/modules/rtctime.md'
         - 'rtcfifo': 'en/modules/rtcfifo.md'