robopi-addon

中文说明

Add-on toolkit for the RoboPi RK3588S platform: WS2812 strip control and SIG/key GPIO helpers. It does not depend on roboparty-base.

• robopi-ws2812: controls 18 daisy-chained WS2812 LEDs through PWM6_M1
• robopi-sig-key: SIG rising-edge LED output and key handling

This package does not install or modify the device tree. PWM6_M1 must already be enabled by the system.

What's included

• robopi-ws2812 command-line controller
• robopi-ws2812 kernel transmitter and /dev/robopi-ws2812
• Solid color, flash, chase, rainbow, and demo effects
• robopi-sig-key SIG/key GPIO helper
• Native ARM64 build support
• DKMS-based kernel module installation with automatic rebuild on kernel updates
• Debian packaging for installation and removal

Commands

The program sends GRB frames through /dev/robopi-ws2812; the kernel module generates the validated 800 kHz PWM6_M1 waveform.

# Turn on with the default dim white color (48, 48, 48)
sudo robopi-ws2812 on

# Turn on with a custom RGB color
sudo robopi-ws2812 on 255 80 0

# Turn off
sudo robopi-ws2812 off

# Solid color: R G B
sudo robopi-ws2812 solid 255 0 0

# Flash: R G B [interval_ms] [count]
# count=0 or omitted: run until Ctrl+C
sudo robopi-ws2812 flash 0 255 0 500 10
sudo robopi-ws2812 flash 0 0 255 200

# Chase: R G B [step_ms] [width]
sudo robopi-ws2812 chase 0 0 255 80 3

# Rainbow: [step_ms]
sudo robopi-ws2812 rainbow 40

# Short demonstration, then turn off
sudo robopi-ws2812 demo

# Show help
robopi-ws2812 --help

Continuous effects stop with Ctrl+C and turn the strip off before exiting.

Parameters

Parameter	Range	Description
R G B	0-255	Red, green, and blue brightness
interval_ms / step_ms	10-60000	Animation interval in milliseconds
count	0-1000000	Flash count; 0 means continuous
width	1-18	Number of illuminated chase pixels

Start with low RGB values such as 16-64 to avoid excessive power draw.

Build deb package

Build natively on the ARM64 board:

sudo apt install build-essential debhelper
dpkg-buildpackage -us -uc -b

The .deb file will be generated in the parent directory.

Install

The kernel module is built at install time by DKMS against the running kernel, so the matching headers must be available on the target:

sudo apt install dkms linux-headers-$(uname -r)
sudo apt install ../robopi-addon_*_arm64.deb

DKMS rebuilds robopi-ws2812 automatically whenever the kernel is updated. The module is loaded at boot via /etc/modules-load.d/robopi-ws2812.conf.

Uninstall

sudo apt remove robopi-addon
sudo apt purge robopi-addon

The prerm script removes the DKMS module so the driver is also uninstalled from every kernel it was built for.

Compile-time configuration

The following settings are defined near the top of the kernel module src/robopi-ws2812.c and require a rebuild after modification:

#define LED_COUNT       18
#define PWM6_PHYS       0xfebd0020
#define PERIOD_TICKS    18
#define ZERO_TICKS      6
#define ONE_TICKS       12

Validate all timing changes with an oscilloscope.

SIG rising-edge LED trigger

Function	GPIO	GPIO character device	Active state
SIG input	GPIO1_D5	/dev/gpiochip1, offset 29	Rising edge
LED output	GPIO0_C2	/dev/gpiochip0, offset 18	High level

robopi-sig-key starts with the LED off. A low-to-high transition on SIG turns the LED on. A later falling level does not directly turn it off. Exiting the program always turns the LED off.

SIG must remain within the voltage limits of the GPIO1_D5 IO domain. Never drive SIG directly with 5 V.

Foreground test

Latch the LED on after a rising edge:

sudo robopi-sig-key

Expected startup and trigger output:

Started: waiting for SIG rising edge; LED is off.
SIG rising edge -> LED on
KEY_PRESSED

Press Ctrl+C to exit and turn the LED off.

Timed LED output

Keep the LED on for 1000 ms after each rising edge:

sudo robopi-sig-key --led-on-ms 1000

Other options

robopi-sig-key --help
sudo robopi-sig-key --debounce-ms 30
sudo robopi-sig-key --on-press '/opt/my-app/start.sh'
sudo robopi-sig-key --sig-active-low
sudo robopi-sig-key --led-active-low

systemd service

After validating the foreground test, enable the service at boot:

sudo systemctl enable --now robopi-sig-key.service
journalctl -u robopi-sig-key.service -f