work in progress

Digital trainers integrate a breadboard with simple I/O and they are a great tool to learn digital circuits. DIGILAB-R is a vintage style digital trainer designed to be compatible with the Scuola Radio Elettra DIGILAB. It can be used to perform all the experiments in the Digital Electronics distance learning course that was popular in the 80's.

While working with Arduino in industrial applications it's often useful to have a isolated voltages available. Depending on the circuit configuration, ISO02 can generate galvanically isolated unipolar and symmetric voltages from the 5V Arduino power. The circuit is based on a basic push pull configuration and uses an easy to obtain off the shelf transformer.

Arduino shields are ubiquitous and provide a wide range of sensors and interfaces. Commodorino allows their use on a Commodore 64. The interface provides good compatibility with the Arduino Uno platform. Digital I/O, Analog In, SPI, I2C and limited interrupt and Serial port are implemented and additional Micro SD card socket is available for future expansion.

RS232 are still very popular to control legacy equipment. In industrial settings with long cable runs, interference and different ground references it is necessary to have galvanic isolation. ISO232 is a simple implementation using the FTDI FT230X and opto isolators that can reach speeds up to 115200baud.

Schematics

The schematics is divided in four main portions.

USTK01 is a small USB device that allows the connection of thermocouples (using MAX6675 or MAX 31855), humidity sensors (DHT11/DHT22) or any I2C or RS232 device (5V or 3.3V).

Despite the significant advantages in size, weight and efficiency, switching AC-DC supplies are not very common with hobbyist due to their complexity and scarcity of ready to build kits.
PWR01 is a low power (~6W) universal voltage (100-240V) isolated AC-DC flyback converter based on the ST Microelectronics VIPer17. Either 5V or 12V output can be obtained using an off the shelf transformer.

Linear regulators from the 7800 series are often the choice for electronics hobbyists because of their ease of use, versatility, robustness and availability. G78xxHE is a very small DC-DC converter aimed to be a "drop in" replacement for the 7800 series regulators in TO-220 package. Thanks to its high efficiency the G78xxHE does not need to be connected to an heatsink even when delivering the maximum rated 7800 series current (1A) with large Vin-Vout deltas.