// the find
jeelabs/esp-link
esp8266 wifi-serial bridge, outbound TCP, and arduino/AVR/LPC/NXP programmer
esp-link turns an ESP8266 into a WiFi bridge for microcontrollers — transparent serial passthrough, OTA programming of attached AVR/ARM chips, plus MQTT and outbound REST requests that offload the main MCU. Aimed at makers adding network connectivity to existing Arduino/AVR projects without rewriting firmware. The ESP8266 acts as master, handling protocols so the attached MCU doesn't have to.
1. OTA programming of attached AVRs via built-in stk500v1 is genuinely useful — you can reflash an Arduino over WiFi without physical access. 2. Protocol offloading is architecturally sound: the attached MCU sends simple serial commands and esp-link handles MQTT framing, TCP connection management, and HTTP — keeps resource-constrained MCUs out of protocol hell. 3. Breadth of target support (AVR, LPC800-series ARM, ATmega2560) with distinct flash tools (cgioptiboot, cgimega) rather than one-size-fits-all. 4. Self-contained embedded web server with a real UI for configuration, not just a serial terminal — mDNS, sNTP, syslog all included.
1. Dead since 2021, built on Espressif SDK 1.5.4 from 2016 — that SDK is long superseded by ESP-IDF, and this will never see ESP32 support. Anyone starting fresh should use ESP-IDF or MicroPython instead. 2. The 5-minute inactivity timeout on port 23 is hardcoded by the SDK and can't be changed — the README admits this is a known rough edge with no fix. 3. v3.0 custom web pages were never finished; that feature has been 'not ready yet' since at least 2016 and is now permanently stalled. 4. Multiple simultaneous connections to the serial bridge intermix bytes with no framing — the README says 'use with caution' but doesn't offer any alternative, so it's a foot-gun in any multi-client scenario.