Difference between revisions of "Rotary encoder with GPIOs"
From ArmadeusWiki
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# evtest | # evtest | ||
| − | + | No device specified, trying to scan all of /dev/input/event* | |
| + | Available devices: | ||
| + | /dev/input/event0: iMX6UL Touchscreen Controller | ||
| + | /dev/input/event1: rotary1 | ||
| + | ... | ||
</pre> | </pre> | ||
Revision as of 17:21, 3 March 2017
Page under construction...
Informations on this page are not guaranteed !!
Contents
Introduction
This page will explain you how to drive a rotary encoder connected to GPIOs of your APF/OPOS.
Hardware
The instructions were tested on OPOS6ULDev where rotary encoder is connected to GPIOs on RPi compatible connector:
| Encoder | Pin number on RPi connector |
Function |
|---|---|---|
| + | 1 | Power |
| GND | 6 | GND |
| SW | Key press | |
| DT | 32 | |
| CLK | 40 |
Software
- Device tree need to be adapted:
gpio-keys {
compatible = "gpio-keys";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpio_keys>;
user-button {
label = "User button";
gpios = <&gpio2 11 GPIO_ACTIVE_LOW>;
linux,code = <BTN_MISC>;
wakeup-source;
};
+ rotary1_button {
+ label = "rotary1_button";
+ gpios = <&gpio5 2 GPIO_ACTIVE_LOW>;
+ debounce-interval = <10>;
+ linux,code = <28>;
+ };
}
+ rotary1 {
+ compatible = "rotary-encoder";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_rotary1>;
+ gpios = <&gpio5 0 1>, <&gpio5 1 1>;
+ linux,axis = <1>; /* REL_Y */
+ rotary-encoder,relative-axis;
+ };
...
&iomuxc {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpios>;
...
+ pinctrl_rotary1: rotary1grp {
+ fsl,pins = <
+ MX6UL_PAD_SNVS_TAMPER0__GPIO5_IO00 0x0b0b0
+ MX6UL_PAD_SNVS_TAMPER1__GPIO5_IO01 0x0b0b0
+ >;
+ };
...
- you can then replace /boot/imx6ul-opos6uldev.dtb file on your rootfs and reboot
- Rotary should then be recognized by evtest tool:
# evtest No device specified, trying to scan all of /dev/input/event* Available devices: /dev/input/event0: iMX6UL Touchscreen Controller /dev/input/event1: rotary1 ...
