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qmk_firmware/docs/internals_gpio_control.md
James Young b272c035ba
[Docs] Random Fixes (#8340)
* fix CLI section links in the Summary

* fix heading in Pointing Device doc

* fix headings in PS/2 Mouse Support doc

* add explicit section ids to I2C Master Driver doc

* reformat GPIO Controls table

Much like the I2C Master Driver doc, I found this a bit less than ideal to read. (The table was actually wider than the space available for it.)

Reformatted so each GPIO function is an H3 heading, followed by a paragraph and a table of each architecture's old-style function.

* migrate changes from I2C Master Driver doc to Japanese translation

* add explicit anchors to I2C Master Driver docs

* fix code block language markers

The language markers are case-sensitive; using the wrong case means the syntax highlighting doesn't work.

Good: ```c
Bad: ```C

* restore Japanese I2C Master Driver doc to current master

Can't update the internal tracking references accurately until the changes to the English doc are committed to master.

* add explicit anchors to edited files

* change ChibiOS/ARM to ARM/ChibiOS

Because ARM/ATSAM is also a thing that exists.

* fix code block language markers again

Used the wrong markers in a few spots. Also these are apparently always supposed to be lowercase.

* add section anchors to cli.md

* restore table formatting on GPIO Control doc

* remove changes to _summary.md
2020-03-15 20:29:11 -07:00

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Markdown

# GPIO Control :id=gpio-control
QMK has a GPIO control abstraction layer which is microcontroller agnostic. This is done to allow easy access to pin control across different platforms.
## Functions :id=functions
The following functions can provide basic control of GPIOs and are found in `quantum/quantum.h`.
|Function |Description | Old AVR Examples | Old ChibiOS/ARM Examples |
|------------------------|--------------------------------------------------|-------------------------------------------------|-------------------------------------------------|
| `setPinInput(pin)` | Set pin as input with high impedance (High-Z) | `DDRB &= ~(1<<2)` | `palSetLineMode(pin, PAL_MODE_INPUT)` |
| `setPinInputHigh(pin)` | Set pin as input with builtin pull-up resistor | `DDRB &= ~(1<<2); PORTB \|= (1<<2)` | `palSetLineMode(pin, PAL_MODE_INPUT_PULLUP)` |
| `setPinInputLow(pin)` | Set pin as input with builtin pull-down resistor | N/A (Not supported on AVR) | `palSetLineMode(pin, PAL_MODE_INPUT_PULLDOWN)` |
| `setPinOutput(pin)` | Set pin as output | `DDRB \|= (1<<2)` | `palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL)` |
| `writePinHigh(pin)` | Set pin level as high, assuming it is an output | `PORTB \|= (1<<2)` | `palSetLine(pin)` |
| `writePinLow(pin)` | Set pin level as low, assuming it is an output | `PORTB &= ~(1<<2)` | `palClearLine(pin)` |
| `writePin(pin, level)` | Set pin level, assuming it is an output | `(level) ? PORTB \|= (1<<2) : PORTB &= ~(1<<2)` | `(level) ? palSetLine(pin) : palClearLine(pin)` |
| `readPin(pin)` | Returns the level of the pin | `_SFR_IO8(pin >> 4) & _BV(pin & 0xF)` | `palReadLine(pin)` |
## Advanced Settings :id=advanced-settings
Each microcontroller can have multiple advanced settings regarding its GPIO. This abstraction layer does not limit the use of architecture-specific functions. Advanced users should consult the datasheet of their desired device and include any needed libraries. For AVR, the standard avr/io.h library is used; for STM32, the ChibiOS [PAL library](http://chibios.sourceforge.net/docs3/hal/group___p_a_l.html) is used.