# Atom Echo (C008-C / "Atom Voice") Pin Map

## Speaker + Microphone

| ESP32 Pin | Component      | Function  |
| --------- | -------------- | --------- |
| G22       | NS4168 amp     | I2S DATA  |
| G19       | NS4168 amp     | I2S BCLK  |
| G33       | NS4168 amp     | I2S LRCK  |
| G23       | SPM1423 mic    | PDM CLK   |
| G33       | SPM1423 mic    | PDM DATA  |

Note: **G33 is shared** between the amp's LRCK and the mic's DATA line — this is why the stock firmware can't record and play simultaneously ([confirmed in community docs][m5-docs]). Not a problem for our use case (output only), but something to remember if the design ever wants local wake-word.

## Human interface

| ESP32 Pin | Component      | Function  |
| --------- | -------------- | --------- |
| G27       | SK6812 RGB LED | Data      |
| G39       | Button         | Input (input-only pin) |

## GROVE connector (HY2.0-4P)

| Pin | Color  | Signal |
| --- | ------ | ------ |
| 1   | Black  | GND    |
| 2   | Red    | 5V     |
| 3   | Yellow | G26    |
| 4   | White  | G32    |

## Reserved pins — do not reuse

From the M5Stack docs ([pinmap section][m5-docs]):

> "G19 / G22 / G23 / G33 have been predefined. Do not reuse these pins; otherwise the Atom Echo may be damaged."

## Available for external hardware

- GROVE: G26, G32 (plus 5V / GND)
- Button G39 is reusable if we want a different button function

## Key takeaways for this project

- **I2S output for our external DAC**: route to free pins (G26/G32 on GROVE, plus one more — likely borrowed from the side header) rather than the reserved G19/G22/G33. This avoids driving the NS4168 entirely. See [disabling-internal-speaker.md](./disabling-internal-speaker.md).
- **NS4168 shutdown**: not needed — just don't send it I2S data (software-only solution in ESPHome, no hardware mod).
- **Button** on G39 is our "start/stop bedtime routine" trigger.
- **RGB LED** on G27 is a nice status indicator (idle / playing / HA unreachable / etc.)
- **GROVE G26/G32** can be used for I2S out to the external DAC, or repurposed for a secondary input.

## Sources

- [Atom Echo product docs (M5Stack)][m5-docs] — pin map table, reserved-pin warning
- [ESP32-PICO-D4 datasheet](../datasheets/esp32-pico_series_datasheet_en.pdf) — for confirming GPIO capabilities (input-only pins, drive strength, etc.)

[m5-docs]: https://docs.m5stack.com/en/atom/atomecho