diff --git a/docs/docs/config/kscan.md b/docs/docs/config/kscan.md index 5c70f4ba..296cb4a1 100644 --- a/docs/docs/config/kscan.md +++ b/docs/docs/config/kscan.md @@ -86,6 +86,18 @@ By default, a switch will drain current through the internal pull up/down resist `toggle-mode` applies to all switches handled by the instance of the driver. To use a toggle switch with other, non-toggle, direct GPIO switches, create two instances of the direct GPIO driver, one with `toggle-mode` and the other without. Then, use a [composite driver](#composite-driver) to combine them. +Assuming the switches connect each GPIO pin to the ground, the [GPIO flags](https://docs.zephyrproject.org/3.2.0/hardware/peripherals/gpio.html#api-reference) for the elements in `input-gpios` should be `(GPIO_ACTIVE_LOW | GPIO_PULL_UP)`: + +```devicetree + kscan0: kscan { + compatible = "zmk,kscan-gpio-direct"; + input-gpios + = <&pro_micro 4 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)> + , <&pro_micro 5 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)> + ; + }; +``` + ## Matrix Driver Keyboard scan driver where keys are arranged on a matrix with one GPIO per row and column. @@ -122,6 +134,24 @@ The `diode-direction` property must be one of: | `"row2col"` | Diodes point from rows to columns (cathodes are connected to columns) | | `"col2row"` | Diodes point from columns to rows (cathodes are connected to rows) | +Given the `diode-direction`, the [GPIO flags](https://docs.zephyrproject.org/3.2.0/hardware/peripherals/gpio.html#api-reference) for the elements in `row-` and `col-gpios` should be set appropriately. +The output pins (e.g. columns for `col2row`) should have the flag `GPIO_ACTIVE_HIGH`, and input pins (e.g. rows for `col2row`) should have the flags `(GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)`: + +```devicetree + kscan0: kscan { + compatible = "zmk,kscan-gpio-matrix"; + diode-direction = "col2row"; + col-gpios + = <&pro_micro 4 GPIO_ACTIVE_HIGH> + , <&pro_micro 5 GPIO_ACTIVE_HIGH> + ; + row-gpios + = <&pro_micro 6 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)> + , <&pro_micro 7 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)> + ; + }; +``` + ## Composite Driver Keyboard scan driver which combines multiple other keyboard scan drivers.