fix gpio doc, refer to gpio overview from module docs

docs/en/modules/dht.md

@@ -15,7 +15,7 @@ Read DHT11 humidity temperature combo sensor.
 `dht.read11(pin)`
 
 #### Parameters
-`pin` 0~33, IO index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 - `status` as defined in Constants
@@ -45,7 +45,7 @@ Read DHT21/22/33/43 and AM2301/2302/2303 humidity temperature combo sensors.
 `dht.read2x(pin)`
 
 #### Parameters
-`pin` 0~33, IO index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 - `status` as defined in Constants

docs/en/modules/gpio.md

@@ -57,7 +57,7 @@ Read digital GPIO pin value.
 `gpio.read(pin)`
 
 #### Parameters
-`pin` pin to read, 0 ~ 33 I/O index
+`pin` pin to read, see [GPIO Overview](#gpio-overview)
 
 #### Returns
 0 = low, 1 = high
@@ -70,13 +70,13 @@ Establish or clear a callback function to run on interrupt for a GPIO.
 `gpio.trig(pin, type [, callback])`
 
 #### Parameters
-- `pin` 0 ~ 33 I/O index
+- `pin`, see [GPIO Overview](#gpio-overview)
 - `type` trigger type, one of
-    - `INTR_UP` for trigger on rising edge
-    - `INTR_DOWN` for trigger on falling edge
-    - `INTR_UP_DOWN` for trigger on both edges
-    - `INTR_LOW` for trigger on low level
-    - `INTR_HIGH` for trigger on high level
+    - `gpio.INTR_UP` for trigger on rising edge
+    - `gpio.INTR_DOWN` for trigger on falling edge
+    - `gpio.INTR_UP_DOWN` for trigger on both edges
+    - `gpio.INTR_LOW` for trigger on low level
+    - `gpio.INTR_HIGH` for trigger on high level
 - `callback` optional function to be called when trigger fires, trigger is disabled when omitted. Parameters are:
     - `pin`
     - `level`
@@ -91,11 +91,11 @@ Configuring wake-from-sleep-on-GPIO-level.
 `gpio.wakeup(pin, level)`
 
 #### Parameters
-- `pin` 0 ~ 33 I/O index
+- `pin`, see [GPIO Overview](#gpio-overview)
 - `level` wake-up level, one of
-    - `INTR_NONE` to disable wake-up
-    - `INTR_LOW` for wake-up on low level
-    - `INTR_HIGH` for wake-up on high level
+    - `gpio.INTR_NONE` to disable wake-up
+    - `gpio.INTR_LOW` for wake-up on low level
+    - `gpio.INTR_HIGH` for wake-up on high level
 
 #### Returns
 `nil`
@@ -108,8 +108,8 @@ Set digital GPIO pin value.
 `gpio.write(pin, level)`
 
 #### Parameters
-- `pin` pin to write, 0 ~ 33 I/O index
-- `level` `gpio.HIGH` or `gpio.LOW`
+- `pin` pin to write, see [GPIO Overview](#gpio-overview)
+- `level` 1 or 0
 
 #### Returns
 `nil`

docs/en/modules/i2c.md

@@ -83,8 +83,8 @@ Initialize the I²C interface for master mode.
 
 ####Parameters
 - `id` interface id
-- `pinSDA` 0~33, IO index
-- `pinSCL` 0-33, IO index
+- `pinSDA` IO index, see [GPIO Overview](gpio.md#gpio-overview)
+- `pinSCL` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `speed` bit rate in Hz, positive integer
     - `i2c.SLOW` for 100000 Hz, max for `i2c.SW`
     - `i2c.FAST` for 400000 Hz
@@ -196,8 +196,8 @@ Initialize the I²C interface for slave mode.
 #### Parameters
 - `id` interface id, `i2c.HW0` or `i2c.HW1`
 - `slave_config` table containing slave configuration information
-    - `sda` 0~33, IO index
-    - `scl` 0-33, IO index
+    - `sda` IO index, see [GPIO Overview](gpio.md#gpio-overview)
+    - `scl` IO index, see [GPIO Overview](gpio.md#gpio-overview)
     - `addr` slave address (7bit or 10bit)
     - `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)

docs/en/modules/ow.md

@@ -55,7 +55,7 @@ Stops forcing power onto the bus. You only need to do this if you used the 'powe
 `ow.depower(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `nil`
@@ -71,7 +71,7 @@ Reads a byte.
 `ow.read(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 byte read from slave device
@@ -83,7 +83,7 @@ Reads multi bytes.
 `ow.read_bytes(pin, size)`
 
 #### Parameters
-- `pin` 0~33, I/O index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `size` number of bytes to be read from slave device (up to 256)
 
 #### Returns
@@ -96,7 +96,7 @@ Performs a 1-Wire reset cycle.
 `ow.reset(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 - `1` if a device responds with a presence pulse
@@ -109,7 +109,7 @@ Clears the search state so that it will start from the beginning again.
 `ow.reset_search(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `nil`
@@ -121,7 +121,7 @@ Looks for the next device.
 `ow.search(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `rom_code` string with length of 8 upon success. It contains the rom code of slave device. Returns `nil` if search was unsuccessful.
@@ -136,7 +136,7 @@ Issues a 1-Wire rom select command. Make sure you do the `ow.reset(pin)` first.
 `ow.select(pin, rom)`
 
 #### Parameters
-- `pin` 0~33, I/O index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `rom` string value, len 8, rom code of the slave device
 
 #### Returns
@@ -204,7 +204,7 @@ Sets a pin in onewire mode.
 `ow.setup(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `nil`
@@ -216,7 +216,7 @@ Issues a 1-Wire rom skip command, to address all on bus.
 `ow.skip(pin)`
 
 #### Parameters
-`pin` 0~33, I/O index
+`pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `nil`
@@ -228,7 +228,7 @@ Sets up the search to find the device type `family_code`. The search itself has
 `ow.target_search(pin, family_code)`
 
 #### Parameters
-- `pin` 0~33, I/O index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `family_code` byte for family code
 
 #### Returns
@@ -244,7 +244,7 @@ Writes a byte. If `power` is 1 then the wire is held high at the end for parasit
 `ow.write(pin, v, power)`
 
 #### Parameters
-- `pin` 0~33, I/O index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `v` byte to be written to slave device 
 - `power` 1 for wire being held high for parasitically powered devices
 
@@ -261,7 +261,7 @@ Writes multi bytes. If `power` is 1 then the wire is held high at the end for pa
 `ow.write_bytes(pin, buf, power)`
 
 #### Parameters
-- `pin` 0~33, IO index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `buf` string to be written to slave device
 - `power` 1 for wire being held high for parasitically powered devices
 

docs/en/modules/sigma-delta.md

@@ -59,7 +59,7 @@ Routes the sigma-delta channel to the specified pin. Target prescale and duty va
 
 #### Parameters
 - `channel` 0~7, sigma-delta channel index
-- `pin` 0~33, IO index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 
 #### Returns
 `nil`

docs/en/modules/ws2812.md

@@ -18,7 +18,7 @@ Send data to up to 8 led strip using its native format which is generally Green,
 
 #### Parameters
 Variable number of tables, each describing a single strip. Required elements are:
-- `pin` 0 ~ 33, I/O index
+- `pin` IO index, see [GPIO Overview](gpio.md#gpio-overview)
 - `data` payload to be sent to one or more WS2812 like leds through GPIO2
 
 Payload type could be:
@@ -316,6 +316,3 @@ The concatenated buffer.
 ```
 ws2812.write({pin = 4, data = buffer1 .. buffer2})
 ```
-
-
-