Connect / retrofit any device to the Internet

MQTT-SERIAL module provides secure IoT connectivity for any microcontroller-based product. It works even with the smallest 8-bit microcontrollers, which makes it an ideal solution for retrofitting existing products.

Name Type Hardware Price
COMFI-S1 module ESP32 WROOM32 Contact us
COMFI-S2 module TI CC3220MOD Contact us
COMFI-SM device ESP32 M5Stack Contact us


Embedded module. Needs to be integrated.


Embedded module. Needs to be integrated.


End-user device. Ready to use.

Security Flash encryption. Communication over TLS 1.2
MQTT servers supported AWS IoT, Google IoT, Microsoft Azure, IBM Watson, any private MQTT server
Minumum requirements for the host MCU 8-bit, 1k RAM, 2k flash. No dependencies, no dynamic RAM allocations
Module provisioning Over Serial, over WiFi Access Point, over BLE (WROOM32 only)
Over-The-Air updates of the module For volumes over 1000 units, a free installation of a private management dashboard is included
Over-The-Air updates of the host MCU Requires programming connection. Supported MCUs: STM32, AVR
Technical Support Included. E-mail / Phone, guaranteed SLA

The host microcontroller communicates with the MQTT-SERIAL module via the serial (UART) link, using two simple API functions:

  • mqtt_publish(topic, data); - publish data to the MQTT server
  • mqtt_subscribe(topic, func, cbdata); - subscribe to messages from the MQTT server