ZAR-1 MCU

This is one of my designs for an extendable general-purpose microcontroller.

It has the following features:

1. Several configurable power supplies onboard: 3.3V, 5V, 10V and galvanically isolated 5V,
2. 32-bit STM32Fx/STM32Lx microcontroller,
3. Semtech LORA radio module working at 868 or 433 MHz,
4. Galvanically isolated CAN interface,
5. 4x analog inputs and 2x analog outputs with a configurable voltage range,
6. Analog temperature sensor,
7. Battery-powered real-time clock,
8. Digital inputs and outputs broken out in the form of pin headers to connect to a daughter board.
9. Phoenix Contact housing for DIN-rail or stand-alone applications,
10. Powered by an external 9V-24V DC power supply.

Below, you can see a daughter board, which provides five opto-isolated relays, two RS-485 connections, one RS-232 connection, two USB connections, an EEPROM and a temperature&humidity sensor (a Sensirion SHT21 in this case).

This is what the whole assembly looks like - a ZAR-1 (without the analog and CAN subsystems) plus an EXT1 board in a housing for DIN-rail mounting:

The tests have been very successful and I am very happy with the functionality and flexibility of the design. The Semtech radio provides a nice connectivity between and over buildings on the 868 MHz bands, the RS-232 connection is used to transmit and receive data over a GPRS modem connection, the RS-485 communicate with ZAR-2 microcontrollers which deliver sensor data to ZAR-1. The relays control the heat curtain itself and a human user can monitor and control the devices connected over the LORA radio through the USB connection to a PC.

If you would like to know more about ZAR-1, you can drop me a note at any time using the about page.