Ai Thinker ESP32 A1S Audio Kit board definition for esp-adf

Usage

• Clone the repository by git clone https://github.com/trombik/esp-adf-component-ai-thinker-esp32-a1s.git
• Create components directory in a project directory
• Create a symlink to idf-component-ai-thinker-esp32-a1s/components/ai-thinker-esp32-a1s under components.
• Run idf.py menuconfig
• Select Custom audio board under Audio HAL > Audio board
• Select a custom board under Custom Audio Board

Supported boards

There are two different Ai Thinker A1S chips in the market: one with ac101 audio codec, another with es8388. Both chips has the same name. The one with ac101 is EoLed, the vendor claims. In addition, there are different Ai Thinker A1S Audio Kit boards in the market: A1S es8388 chips with different pin assignments.

• Ai Thinker A1S with es8388 variant 5 (probably the latest variant available in AliExpress)
• Ai Thinker A1S with es8388 variant 7

What works

Here is a list of tested peripherals:

• Audio output to speakers
• Keys
• On-board LEDs
• Bluetooth
• Mic input
• Line input
• On-board microphones
• SD card
• Battery charger

Speaker outputs

To test speaker outputs, use ${ADF_PATH}/examples/player/pipeline_http_mp3.

Keys

To test keys, use ${ADF_PATH}/examples/checks/check_board_buttons.

Name	Function in esp-adf
KEY1	Mode
KEY2	Rec
KEY3	Play
KEY4	Set
KEY5	Volume down
KEY6	Volume up

Note that KEY2 cannot be used with SD card because the GPIO for KEY2 is shared with SD card peripheral.

According to the schematic, ADC Button Peripheral is supposed to work. However, my board does not have necessary resistors (R60, R61 ...). If yours has them, give CONFIG_AI_THINKER_ESP32_A1S_ES8388_BUTTON_KEY_ADC a try.

On-board LED

The board has two red LEDs connected to GPIO pins. By default, only one LED is useable. Unlike official development boards from espressif, the color is red. esp-adf provides get_blue_led_gpio() and get_green_led_gpio(), not one for red LED.

To test the LED, use ${ADF_PATH}/examples/checks/check_display_led.

Bluetooth

To test a2dp sink, use ${ADF_PATH}/examples/player/pipeline_a2dp_sink_stream.

a2dp source has not been tested.

On-board microphones

To test on-board microphones, use ${ADF_PATH}/examples/recorder/pipeline_raw_http.

See also "Known issues" below.

Battery charger

The battery charger should work, but no GPIO pin is connected to the charger circuit. As such, the battery service in esp-adf cannot be used.

Tested environment

• esp-idf v5.0.2
• esp-adf master

Known issues

The Audio Kit board has hardware bugs. Two capacitors must be connected to on-board microphones. See a post in Home Assistant forum.

Resources

• The‘AI Thinker Audio Kit' Arduino Challenge A series of posts about Ai Thinker ESP32 A1S Audio Kit
• Schematic
• arduino-audiokit/tree/main/src/audio_board An implementation for Arduino
• ES8388 User Guide