This example demonstrates how to use the relay channel component to control a 3-channel setup with button inputs and LED status indication. It showcases:

Basic relay channel operations (forward/reverse running, stopping)
Secondary operations (tilting, direction flipping)
State change event handling with a listener
Relay channel run limit
Button event handling using esp-iot-solution's button component
Visual feedback using esp-iot-solution's LED indicator component

How to Use Example

This example has been tested on an ESP32-C3-DevKitM-1U board. However, it can be adapted to any ESP32-based board with at least six available GPIO pins by adjusting the configuration options.

Hardware Required

An ESP32-based development board
2 relays connected to GPIO pins (default: GPIO4, GPIO5)
3 buttons connected to GPIO pins:
- UP button (default: GPIO0)
- DOWN button (default: GPIO1)
- STOP button (default: GPIO2)
- SELECT button (default: GPIO3)
LED indicators for status indication of each channel (default: GPIO4, GPIO10 and GPIO9 respectively)

Hardware Schematic

Relay blocks are ommitted for simplicity. You can refer to schematic of the Single-channel example for a fully implemented relay block.

Note

A single relay channel consists of two relay block and two GPIO pins.

Configuration

The example can be configured through menuconfig under "Relay Channel Multi Example Configuration":

Button active level (EXAMPLE_RLCHN_BTN_ACTIVE_LEVEL)
- Select between active LOW or HIGH logic level for buttons
GPIO assignments:
- UP button pin (EXAMPLE_RLCHN_BTN_UP_IO_NUM, default: 0)
- DOWN button pin (EXAMPLE_RLCHN_BTN_DOWN_IO_NUM, default: 1)
- STOP button pin (EXAMPLE_RLCHN_BTN_STOP_IO_NUM, default: 2)
- SELECT button pin (EXAMPLE_RLCHN_BTN_SELECT_IO_NUM, default: 3)
- LED indicator pin (EXAMPLE_RLCHN_LED_INDICATOR1_IO_NUM, default: 4)
- LED indicator pin (EXAMPLE_RLCHN_LED_INDICATOR2_IO_NUM, default: 10)
- LED indicator pin (EXAMPLE_RLCHN_LED_INDICATOR3_IO_NUM, default: 9)
Long press timing:
- EXAMPLE_RLCHN_BTN_LONG_PRESS_TIME_MS: Duration for long press actions (1500-3000ms, default: 2000ms)

Button Operations

The example uses esp-iot-solution's button component to handle the following operations:

UP button:
- Short press: Start forward movement
- Long press: Start forward tilt (stops on release)
DOWN button:
- Short press: Start reverse movement
- Long press: Start reverse tilt (stops on release)
STOP button:
- Short press: Stop movement
- Long press: Flip movement direction
SELECT button:
- Short press: Selects a channel to operate
- Long press: Selects all channels to operate in batch

LED Indicator States

The example uses esp-iot-solution's led_indicator component to show different states:

Running: LED blinks at 300ms on, 100ms off
Tilting: Fast blink at 100ms on, 50ms off
Operation Success: Two quick blinks
Operation Fail: One long blink

Dependencies

This example requires:

ESP-IDF v4.1 or later
esp-iot-solution components:
- button v4.1.1 or later
- led_indicator v1.1.1 or later
relay_chn component

Example Output

When the application boots, it will wait for a button event. Then ta state listener will print state changes.

I (269) main_task: Calling app_main()
I (269) RELAY_CHN_MULTI_EXAMPLE: Initializing relay channel
I (279) gpio: GPIO[18]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (279) gpio: GPIO[19]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (289) gpio: GPIO[5]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (299) gpio: GPIO[6]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (309) gpio: GPIO[7]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (319) gpio: GPIO[8]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (329) RELAY_CHN_MULTI_EXAMPLE: Initializing buttons
I (329) RELAY_CHN_MULTI_EXAMPLE: Initializing buttons with active level: 0
I (339) gpio: GPIO[0]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (339) button: IoT Button Version: 4.1.3
I (349) gpio: GPIO[1]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (359) gpio: GPIO[2]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (359) gpio: GPIO[3]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (369) RELAY_CHN_MULTI_EXAMPLE: Setting up button callbacks. Configured long press time: 2000 ms
I (379) RELAY_CHN_MULTI_EXAMPLE: Initializing LED indicator
I (389) gpio: GPIO[4]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (389) led_indicator: LED Indicator Version: 1.1.1
I (399) gpio: GPIO[4]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
I (409) led_indicator: Indicator create successfully. type:GPIO mode, hardware_data:0x3fc96498, blink_lists:custom
I (419) gpio: GPIO[10]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (429) led_indicator: LED Indicator Version: 1.1.1
I (429) gpio: GPIO[10]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
I (439) led_indicator: Indicator create successfully. type:GPIO mode, hardware_data:0x3fc965a4, blink_lists:custom
I (449) gpio: GPIO[9]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (459) led_indicator: LED Indicator Version: 1.1.1
I (459) gpio: GPIO[9]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
I (469) led_indicator: Indicator create successfully. type:GPIO mode, hardware_data:0x3fc966b0, blink_lists:custom
I (479) RELAY_CHN_MULTI_EXAMPLE: Relay Channel Multi Example is ready to operate
I (489) main_task: Returned from app_main()
I (3759) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to FORWARD
I (6639) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from FORWARD to STOPPED
I (7439) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from STOPPED to IDLE
I (7439) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to TILT_FORWARD
I (8119) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from TILT_FORWARD to IDLE
I (13579) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to TILT_REVERSE
I (14419) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from TILT_REVERSE to IDLE
I (20319) RELAY_CHN_MULTI_EXAMPLE: Selected channel: 1
I (21479) RELAY_CHN_MULTI_EXAMPLE: Selected channel: 2
I (22229) RELAY_CHN_MULTI_EXAMPLE: Selected channel: 0
I (23169) RELAY_CHN_MULTI_EXAMPLE: Selected channel: 1
I (29039) RELAY_CHN_MULTI_EXAMPLE: Selected all channels
I (35419) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to FORWARD
I (35419) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from IDLE to FORWARD
I (35419) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from IDLE to FORWARD
I (39349) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from FORWARD to STOPPED
I (39349) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from FORWARD to STOPPED
I (39359) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from FORWARD to STOPPED
I (40149) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from STOPPED to IDLE
I (40149) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to TILT_FORWARD
I (40159) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from STOPPED to IDLE
I (40169) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from IDLE to TILT_FORWARD
I (40179) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from STOPPED to IDLE
I (40189) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from IDLE to TILT_FORWARD
I (41699) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from TILT_FORWARD to IDLE
I (41699) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from TILT_FORWARD to IDLE
I (41709) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from TILT_FORWARD to IDLE
I (64129) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to TILT_REVERSE
I (64129) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from IDLE to TILT_REVERSE
I (64139) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from IDLE to TILT_REVERSE
I (68929) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from TILT_REVERSE to IDLE
I (68929) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from TILT_REVERSE to IDLE
I (68939) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from TILT_REVERSE to IDLE
I (280109) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from IDLE to FORWARD
I (280109) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from IDLE to FORWARD
I (280109) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from IDLE to FORWARD
I (283219) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from FORWARD to STOPPED
I (283219) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from STOPPED to REVERSE_PENDING
I (283229) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from FORWARD to STOPPED
I (283239) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from STOPPED to REVERSE_PENDING
I (283249) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from FORWARD to STOPPED
I (283259) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from STOPPED to REVERSE_PENDING
I (284019) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #0, from REVERSE_PENDING to REVERSE
I (284019) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #1, from REVERSE_PENDING to REVERSE
I (284029) RELAY_CHN_MULTI_EXAMPLE: example_event_listener: State change for #2, from REVERSE_PENDING to REVERSE