ESP32 and ESP32-C3 in C, from blinking a GPIO to joining a real overlay network — ESP-IDF, Wi-Fi, and what actually fits.
8 posts
A sensor node BOM audited honestly: what the board, regulator, sensor and radio choices really cost your ESP32 battery life, with a Python model computing the real average current, battery life and monthly data budget.
A field guide to debugging ESP32 TCP: how lwIP socket buffers, Wi-Fi retries and Nagle/delayed-ACK interactions produce stalls, resets and half-open connections, which stats and Wireshark views actually reveal a TCP retransmission, and an ESP-IDF snippet plus a checklist.
Vendor clouds are a liability. Here is how self-hosted firmware update works on the ESP32: two app partitions plus an OTA data partition, the esp_ota_* APIs, signed images, and rollback when a new build fails to boot.
A practical guide to ESP32 power management on the ESP32-C3: why the Wi-Fi radio dominates the budget, what active, modem sleep, light sleep and deep sleep each cost in connectivity, how DTIM and listen interval trade latency for battery life, and how to measure real current cheaply.
MQTT fits a microcontroller's budget better than most IoT messaging stacks — a two-byte minimum header, publish/subscribe decoupling, and QoS you can dial down. Here is what an MQTT ESP32 system actually costs once TLS, certificates and reconnects enter the picture.
A practical ESP32 vs ESP8266 buying guide for 2026: CPU, RAM, flash, Wi-Fi, BLE, GPIO, security, power, toolchains and price tiers, plus a decision table and concrete picks by use case — including when an ESP32-C3 is the right default.
A practical ESP-IDF tutorial for the ESP32-C3: choosing between Arduino, PlatformIO and ESP-IDF, installing the toolchain, the project layout, a minimal app_main, GPIO blink, UART logging and a working Wi-Fi station — with copyable commands.
ESPTier reimplements the EasyTier v2.6.4 wire protocol in plain C on an ESP32-C3 — TCP framing, SipHash-1-3 identity, AES-128-GCM, route sync and forwarding — so a constrained MCU becomes a real, pingable member of an overlay network.