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HiFi-ESP32 and HiFi-Esparagus

The Sonocotta HiFi-ESP32 boards pair an ESP32 or ESP32-S3 with a TI PCM5100 I2S DAC and a line-level output. There is no amplifier on board, so these feed an existing amp or a pair of active speakers.

The PCM5100 is a plain I2S DAC: no I2C control port, no mute pin and no hardware volume register. The firmware therefore does volume in software and the board support code has nothing to do beyond bringing up the SPI bus that Ethernet and the display share.

Variants

Environment Chip Ethernet Display Bluetooth Prebuilt
hifi-esp32 ESP32 yes SH1106 OLED — —
hifi-esp32-bt ESP32 yes SH1106 OLED yes yes
hifi-esparagus ESP32 — — — —
hifi-esparagus-bt ESP32 — — yes yes
hifi-esp32-s3 ESP32-S3 yes SH1106 OLED — yes
hifi-esparagus-s3 ESP32-S3 — — — yes

The Esparagus variants are the same audio design without the Ethernet jack and the display header; they carry a WS2812 status LED instead. Bluetooth Classic exists only on the original ESP32, so there is no -bt build for either S3 variant.

On an ESP32 the published binary is the Bluetooth one. Build hifi-esp32 or hifi-esparagus yourself if you would rather have the RAM and flash back.

Features

  • PCM5100 line-level DAC, all 8 MB flash
  • Software volume control — the DAC has no volume register
  • Bluetooth A2DP on the ESP32 variants
  • W5500 SPI Ethernet with automatic WiFi failover, on the non-Esparagus variants
  • SH1106 OLED over SPI, sharing the Ethernet bus, on the non-Esparagus variants

Flashing

Use the HiFi installer for your board on the flashing page.

# ESP32 — AirPlay + Bluetooth + Ethernet + OLED
pio run -e hifi-esp32-bt -t upload
pio run -e hifi-esp32-bt -t uploadfs

# ESP32 — Esparagus variant, AirPlay + Bluetooth over WiFi
pio run -e hifi-esparagus-bt -t upload
pio run -e hifi-esparagus-bt -t uploadfs

# ESP32-S3 — AirPlay + Ethernet + OLED
pio run -e hifi-esp32-s3 -t upload
pio run -e hifi-esp32-s3 -t uploadfs

# ESP32-S3 — Esparagus variant
pio run -e hifi-esparagus-s3 -t upload
pio run -e hifi-esparagus-s3 -t uploadfs

idf.py set-target esp32
idf.py -DSDKCONFIG_DEFAULTS="config/sdkconfig.defaults;config/sdkconfig.defaults.hifi-esp32;config/sdkconfig.defaults.bt" build
idf.py -p /dev/ttyUSB0 flash

Swap in config/sdkconfig.defaults.hifi-esp32-s3 after idf.py set-target esp32s3 for the S3 revision, and drop config/sdkconfig.defaults.bt for a build without Bluetooth.

Default GPIO assignments

Function ESP32 ESP32-S3 Notes
I2S BCK 26 14 Bit clock
I2S WS 25 15 Word select (LRCLK)
I2S DO 22 16 Serial audio data
I2S MCLK — — Not used; the PCM5100 recovers its own clock
Status LED 33 9 Addressable RGB, Esparagus variants only
SPI SCLK 18 12 Shared by Ethernet and display
SPI MOSI 23 11 Shared by Ethernet and display
SPI MISO 19 13 Ethernet only
Ethernet CS 5 10 W5500
Ethernet INT 35 6 W5500
Ethernet RST 14 5 W5500
Display CS 15 39 SH1106 OLED
Display DC 4 40 SH1106 OLED
Display RST 32 38 SH1106 OLED

The Esparagus variants use the same I2S pins and leave the SPI block unconfigured.