LEDs and basic GPIO example application

Description

The application leds_shell is a basic example, which allows easy, interactive control of internal board LEDs, and basic GPIO for externally connected simple devices (for e.g. additional LEDs, relay, motors - via dedicated drivers, etc.) via the shell.

In particular, this example shows:

• on/off and toggle internal board LEDs.
• initialize GPIO port in output mode.
• set GPIO port state to HIGH or LOW.

Shell command

The following commands are available:

• led: allows switching on/off or toggle internal board LEDs.
• gpio: allows initialization of GPIO port and set state to HIGH/LOW.
• help: default RIOT command, which shows available commands.

Usage on BOARD=native

• Build and run leds_shell example application on the native target, as Linux application:

$ make all term
[...]
RIOT native interrupts/signals initialized.
RIOT native board initialized.
RIOT native hardware initialization complete.

main(): This is RIOT! (Version: 2021.07-devel-10893-gb2e97-example-leds_shell)
This board has 2 LEDs
>

• List the available commands:

> help
help
Command              Description
---------------------------------------
gpio                 GPIO pin initialization and set port state HIGH/LOW
led                  Switch on/off or toggle on-board LEDs

• Enable internal LED0 and LED1 (the native target has two virtual LEDs):

> led 0 on
led 0 on
LED_RED_ON

> led 1 on
led 1 on
LED_GREEN_ON

Usage on actual hardware - BOARD=stm32f469i-disco

• Build and flash leds_shell example application on sample board, for example stm32f469i-disco target, which has 4 internal LEDs:

$ make all BOARD=stm32f469i-disco flash term
[...]
main(): This is RIOT! (Version: 2021.07-devel-10894-g2ad22b9-example-leds_shell)
This board has 4 LEDs
> help
help
Command              Description
---------------------------------------
gpio                 GPIO pin initialization and set port state HIGH/LOW
led                  Switch on/off or toggle on-board LEDs

• Switch on/off internal LEDs using led command and appropriate LED id.
• Initialize GPIO port using gpio init.
• Change state of GPIO port using gpio set and gpio clear.