Embedded & Devices / Built / prototype
LOUP ESP32-S3 Connected Voice Device
Custom ESP32-S3 voice device spanning codec bring-up, I2S audio, AEC, jitter/playout, SIP/RTP, e-paper UI, controls, provisioning and OTA.
OVERVIEW
What I built.
Custom ESP32-S3 voice device spanning codec bring-up, I2S audio, AEC, jitter/playout, SIP/RTP, e-paper UI, controls, provisioning and OTA.
Owned the ESP32-S3 firmware path across audio capture/playback, device controls, provisioning, SIP/RTP integration and OTA.
Integrated the ES7210 microphone path and ES8311 speaker path over I2S/I2C, including channel mapping and AEC-reference work.
Built and preserved known-good firmware releases while debugging crackle, jitter, echo, clocking and PBX interactions.
SYSTEM ARCHITECTURE
How the system is divided.
ESP32-S3 device firmware -> Wi-Fi -> SIP/PBX signaling -> RTP media -> remote endpoint.
Microphone/codec -> I2S -> audio processing/AEC -> RTP uplink; RTP downlink -> jitter/playout -> I2S -> speaker codec.
Parent/backend control plane remains separate from device SIP credentials and firmware ownership.
NETWORK / DATA FLOW
What talks to what.
TECHNOLOGY STACK
The technical surface.
IMPLEMENTATION
How it works in practice.
- 01
ESP32-S3 device firmware -> Wi-Fi -> SIP/PBX signaling -> RTP media -> remote endpoint.
- 02
Microphone/codec -> I2S -> audio processing/AEC -> RTP uplink; RTP downlink -> jitter/playout -> I2S -> speaker codec.
- 03
Parent/backend control plane remains separate from device SIP credentials and firmware ownership.
TESTING & VALIDATION
How I know it works.
Codec detection and I2S bring-up on EVT hardware
Controlled A/B firmware builds with known-good rollback points
Serial timing/log analysis during live calls
Wireshark/RTP packet inspection for burst, gap and sequence behavior
Long-call stability tests plus echo checks at multiple speaker levels
EXTERNAL SERVICES & DEPENDENCIES
What sits outside the core.
ENGINEERING EVIDENCE
Artifacts behind the claims.
BOUNDARIES / CONSTRAINTS
What the project does not pretend to solve.
—Real-time audio deadlines on ESP32-S3
—8 kHz telephony vs 16 kHz playback path
—Acoustic echo depends on physical enclosure and gain
—Firmware must remain manufacturer-independent
RESULT / CURRENT STATE
What this produced.
A working connected voice-device platform with stable two-way calling, a preserved firmware baseline, device lifecycle planning and a path toward production provisioning and OTA.
DEEP CASE STUDY AVAILABLE