Choice of processor chip

The first Gratheon beehive sensor kit should optimize for DIY availability, simple firmware support, and enough power for HTTPS telemetry. That makes ESP32-WROOM DevKit the default MVP choice.

Recommendation

Chip / board Networking Strength Weakness Gratheon use
ESP32-WROOM DevKit WiFi, BLE Very common, cheap, Arduino-supported, enough RAM/CPU for TLS + HX711 + sensors + deep sleep. Dev boards are not the lowest-power option; quality varies by clone. Default DIY MVP.
ESP32-C3 WiFi, BLE Lower cost/power, RISC-V, modern Espressif support. Fewer pins/peripherals; less headroom for future audio/ML. Second supported board after MVP firmware stabilizes.
ESP32-S3 WiFi, BLE More RAM/CPU and USB; better for future audio/TinyML experiments. More expensive than needed for a scale. Acoustic/edge-ML prototypes, not base scale.
ESP8266 WiFi Cheap and proven for simple telemetry. Older, less RAM, weaker TLS/support path. Only for community ports, not official first kit.
STM32 / GD32 + radio Depends on module Stable embedded platform, good for custom low-power PCB. Adds radio/module complexity and toolchain support burden. Defer until custom PCB.
RP2040 + radio Depends on module Great tooling and IO. No native WiFi on plain RP2040; higher integration burden. Not recommended for MVP.
nRF52 BLE Excellent low-power BLE. Needs gateway; not ideal for direct internet telemetry. Useful for future sensor nodes, not first WiFi kit.
Arduino Mega / ATmega None Familiar educational board. Needs extra networking, too bulky/power-hungry. Avoid for product.

Connectivity decision rule

  1. WiFi first for the public DIY kit: simplest onboarding and cheapest support.
  2. ESP-NOW or LoRa gateway second for apiaries where multiple hives are near each other but there is no WiFi at every hive.
  3. LTE-M/NB-IoT cellular last for paid remote-field kits because modems, antennas, SIM provisioning, and power management raise complexity and cost.

Firmware implications

  • Keep a single firmware codebase with board-specific pin maps.
  • Default outdoor reporting interval should be 10–15 minutes; 1 minute is useful for demos but wastes battery.
  • Use deep sleep between readings and power-gate the HX711/sensors where possible.
  • Store WiFi, endpoint, hiveId, API token, send interval, and calibration factor in non-volatile memory.
  • Send JSON to POST /iot/v1/metrics with timestamp and dedupeKey so retries are safe.

Potential sources