01
Traffic Light Board
RGB style traffic LEDs plus S3 button control.
Hi3861
An OpenHarmony-based Hi3861 embedded project covering traffic light, colorful light, environment monitoring, and AT command modules.
02
Colorful Light Board
Buzzer and RGB synchronization with sensor fusion.
03
Environment Monitor Board
MQ 2, AHT20, OLED and alarm pipeline.
04
AT Command Module
Custom AT command and serial communication flow.
At a glance
This project organises OpenHarmony embedded exercises on the Hi3861 into four tracks: a traffic-light state machine, lighting with buzzer coordination, environmental data acquisition, and custom AT commands. Each track first implements control of a single peripheral, then combines it with other modules. Together the four scenarios cover input, processing and output.
- Four tracksTraffic, lighting, environment and AT commands, progressing from single-point control to multi-task coordination.
- Independently runnable scenariosEach track is a complete, demonstrable scenario whose result can be observed directly.
- Source available for referenceEach track maps to its own program files, and the README can be read online.
About this project
What it addresses
A common situation in embedded learning is knowing each peripheral individually but lacking experience in organising them into a complete system. This project arranges GPIO, PWM, sensors and serial communication into a learning path of four independently runnable scenarios, ordered by difficulty.
What the four tracks contain
The traffic light uses a state machine to switch between signals and detect illegal horn use; the lighting track generates light effects through PWM and coordinates them with a buzzer; environmental monitoring samples temperature, humidity and light over ADC and I²C and displays them on an OLED; the AT command track extends the serial port into a customisable command interface.
What it uses
A Hi3861 development board with OpenHarmony LiteOS-M, developed in C, covering GPIO, PWM, ADC, I²C and an OLED display, as well as UART serial communication.
How to read it
Choose a board following the module order on this page, check the pin assignments and peripherals, then open the corresponding README for the source layout and build steps. A full README reading page is also provided; reproducing the physical results requires the matching board and components.
Project Structure
Modular directories for independent activation and testing.
Hi3861 rayawa hello traffic_light colorful_light environment at_command demolink iothardware samgr startup
01
Module 1 ｜ Traffic Light Board
GPIO output and button input collaboration.
Hardware
- Three color LEDs and S3 button
Projects
- light.c
- traffic.c
- ability.c
- button.c
- control.c
Learning Order
light.c → traffic.c → ability.c → button.c → control.c
02
Module 2 ｜ Colorful Light Board
Audio, lighting, and sensing integration.
Hardware
- RGB LED, buzzer, PIR sensor, photoresistor
Projects
- beep.c
- music.c
- led.c
- human_sensor.c
- photosensitive.c
- human_sensor_light.c
Learning Order
beep.c → music.c → led.c → human_sensor.c → photosensitive.c → human_sensor_light.c
03
Module 3 ｜ Environment Monitor Board
Sensor collection, OLED display, threshold alarm.
Hardware
- MQ 2, AHT20, OLED, flame sensor, buzzer
Projects
- mq2_demo.c
- aht20.c/.h
- aht20_demo.c
- oled_ssd1306.c/.h
- oled_demo.c
- enrionment_demo.c
Technical Features
- I2C shared bus
- ADC acquisition
- Realtime OLED display
- Threshold alarm
04
Module 4 ｜ AT Command Development
Custom command registration and serial response.
Project
- cal.c with AT+CALC command
Example
AT+CALC=12,3
Build Flow
- Select module in rayawa/BUILD.gn
- Select source in module BUILD.gn
- Run hb build
- Flash with HiBurn
- Check UART output
Tech Stack
- GPIO PWM I2C ADC
- OpenHarmony CMSIS RTOS2 HiAT
- GN Ninja hb
- HiBurn UART tools