Rotary encoder with GPIOs: Difference between revisions
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(Created page with "{{Under_Construction}} =Introduction= This page will explain you how to drive a rotary encoder connected to GPIOs of your APF/OPOS. =Hardware= The instructions were tested o...") |
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=Hardware= | =Hardware= | ||
The instructions were tested on [[OPOS6ULDev]] where rotary encoder is connected to GPIOs on RPi compatible connector: | The instructions were tested on [[OPOS6ULDev]] where rotary encoder is connected to GPIOs on RPi compatible connector: | ||
{| border="1" cellpadding="5" cellspacing="0" summary="Restart of NFS server depending on your distribution" | |||
+ || 1 | |- style="background:#efefef;" | ||
GND || 6 | ! Encoder !! Pin number <br>on RPi connector !! Function | ||
SW || | |- | ||
DT 32 || | | + || 1 || Power | ||
CLK 40 || | |- | ||
| GND || 6 || GND | |||
|- | |||
| SW || 38 (with 4.7k pullup) || Key press | |||
|- | |||
| DT || 32 || | |||
|- | |||
| CLK || 40 || | |||
|} | |||
=Software= | =Software= | ||
Device | * Device tree need to be adapted: | ||
<source lang=diff> | <source lang=diff> | ||
gpio-keys { | gpio-keys { | ||
| Line 61: | Line 69: | ||
... | ... | ||
</source> | </source> | ||
* you can then replace ''/boot/imx6ul-opos6uldev.dtb'' file on your rootfs and reboot | |||
* Rotary should then be recognized by ''evtest'' tool: | |||
<pre class="apf"> | |||
# evtest | |||
No device specified, trying to scan all of /dev/input/event* | |||
Available devices: | |||
/dev/input/event0: iMX6UL Touchscreen Controller | |||
/dev/input/event1: rotary1 | |||
... | |||
Select the device event number [0-6]: 1 | |||
</pre> | |||
=Links= | =Links= | ||
[[Category:Multimedia]] | [[Category:Multimedia]] | ||
Latest revision as of 16:56, 14 March 2017
Page under construction...
Informations on this page are not guaranteed !!
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 | 38 (with 4.7k pullup) | 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 ... Select the device event number [0-6]: 1
