atom_echo

M5Stack Atom Echo — SIP Intercom (Half-Duplex)

Turns an M5Stack Atom Echo into a SIP intercom using the sip_client component. Mic and speaker share one I2S bus, so calls run in half-duplex push-to-talk mode (half_duplex: true).

Hardware pinout and audio setup follow the official Atom Echo voice-assistant config.

Features

• SIP registration (REGISTER + MD5 Digest) with a PBX (Asterisk/FreePBX/3CX, etc.)
• Half-duplex voice — listen by default; hold the button to talk (PTT)
• Short button press — dial / answer / hang up
• LED status (WiFi, ringing, in-call, PTT)
• Ringtone on incoming calls

Configuration

Example device YAML:

substitutions:
  name: "esp-atom-echo-sip"
  friendly_name: "Atom Echo SIP"
  sip_server: "192.168.0.245"
  sip_username: "103"
  sip_domain: "192.168.0.245"
  sip_destination: "101"

packages:
  remote:
    refresh: always
    url: https://github.com/eigger/espcomponents
    ref: master
    files:
      - packages/device_base.yaml
      - packages/esp32.yaml
      - packages/sip/atom_echo/atom_echo.yaml

Your secrets.yaml must provide:

wifi_ssid: "..."
wifi_password: "..."
ota_password: "..."
sip_password: "..."

Substitutions

Key	Default	Description
sip_server	192.168.1.10	PBX address (IP recommended)
sip_port	5060	SIP server port
sip_username	1000	SIP account (extension)
sip_domain	192.168.1.10	SIP domain / realm
sip_caller_id	ESP Atom Echo	Outgoing display name
sip_destination	1001	Number dialed on short press (idle)
hidden_ssid	false	Set true for a hidden SSID
ringtone_sound_file	timer_finished.wav URL	Incoming-call ringtone
sip_password	—	sip_password in secrets.yaml

Button

Gesture	Idle	Ringing	In call
Short press	Dial sip_destination	Answer	Hang up
Hold (≥150 ms)	—	—	Push-to-talk (transmit)
Hold 10 s	Factory reset	Factory reset	Factory reset

While in a call, a quick tap hangs up; holding the button switches the shared I2S bus from speaker to mic until you release.

LED

State	Color / effect
Boot / waiting for HA	Blue slow pulse (WiFi connected) or warm white
No WiFi	Solid red
Incoming call	Green fast pulse
In call (listening)	Cyan
In call (PTT held)	Orange

Notes

• Codec: G.711 (PCMU/PCMA, 8 kHz) — ensure your PBX allows it.
• Use an IP address for sip_server (hostname DNS is not supported).
• Only one call at a time.
• half_duplex: true is required on Atom Echo; full-duplex is not possible on the shared I2S bus.