Linux Peripheral Features

ADC

analogue to digital converters

Backlight

Enable/read and modify backlight brightness

Camera

Example

CAN Bus

Testing

Connect can0 and can1

<CAN1_D+> connect to <CAN2_D+>

<CAN1_D-> connect to <CAN2_D->

Configure

# ip link set can0 up type can bitrate 125000

# ip link set can1 up type can bitrate 125000

Command

Test 1

# candump can1 &

# cansend can0 12345678#123412341234

The following shows the result

can1 12345678 [6] 12 34 12 34 12 34

Test 2

# cansend can0 133#ababdede

The following shows the result

can1 133 [4] AB AB DE DE

Ethernet

Example

Framebuffer

Example

GPIO

Example

I2C

Example

SPWG/JEDIA

Standard Panels Working Group (SPWG)

Japan Electronic Industry Development Association (JEIDA)

How to setting SPWG/JEIDA mode in RISC?

Modify Register GPR(IOMUXC_GPR2)value

Address : 0x020E0008(h)

BIT6 and BIT8 set "0" (SPWG)

BIT6 and BIT8 set "1" (JEIDA)

One Wire

Example

RTC

Example

SATA

Example

SD/MMC

Example

SPI

Example

UART

Example

USB

Example

Watchdog

Example

IR

To decode the infrared signals and provide an uniform interface

lircd -d /dev/lirc0

used parameters:

-d --device=device    read from given device
-u --uinput           generate Linux input events

Executes commands on an IR signal decoded by lircd,

irexec -d /devlirc0

Note: if show these message after running lircd

lircd: can't open or create /var/run/lirc/lircd.pid
lircd: No such file or directory

It has to add the "/var/run/lirc" folder

mkdir /var/run/lirc

How to debug:

1. To check that signals are decoded correctly

mode2 -d /dev/lirc0

It repeats to show "space" and "pulse" while clicking a control button

space 8451531
pulse 476

2. To check input events.

First, It must add the parameter,"-u", in lircd command

lircd -d /dev/lirc0 -u

It will register at inputX,

input: lircd as /devices/virtual/input/input1 

Run evtest to check events

evtest -d /dev/input/event1