seb/blue-repeat
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity
Page: Speaker Sync (Touch)
Pages
3-Board Relay Wiring Carrier PCB and BOM Guest Channel Wiring Hardware Design v0.1 Hub Control Bus (I2C) LED and Music Sync Power and Battery Small Build Speaker Sync (Touch) Stack Connector and Addressing
Clone
1
Speaker Sync (Touch)
blue — ESP32/PlatformIO firmware edited this page 2026-06-10 14:19:02 -04:00
Table of Contents

Speaker Sync (touch pads)

JBL and Cardo have independent Bluetooth buffering, so one lags the other. Each source board has an adjustable delay (0-200 ms) you trim live, by ear, with two capacitive-touch pads. The value is saved to flash (survives power-cycles).

Pad Pin Action
+ GPIO4 tap = +5 ms, hold = ramp up
- GPIO27 tap = -5 ms, hold = ramp down
  • Attach a short wire or a bit of foil to GPIO4 and GPIO27 on each source board and touch the end (a bare header pin is hard to trigger).
  • Raise the delay on whichever speaker is early until the two line up.
  • Touch threshold is ~40 (untouched reads ~115-130); adjust in firmware if your pads read differently.

Why no Wi-Fi/phone UI: Wi-Fi + Bluetooth-A2DP + the audio buffer exceed the classic ESP32's RAM and starve the Bluetooth stack (it won't connect to a speaker). So sync control is local capacitive touch instead of a web page.