Relay2 – new Raspberry Pi Zero add-on board

September 29, 2016

Relay2 is my latest RPi Zero add-on board. It’s designed to control low voltage and small-ish current devices such as DC motors, servos etc.


Relay2 is a 2-ch Relay board with two Change-Over (CO) relays. Each relay is good for 30V AC/DC at 1A. The relays can handle a greater voltage than 30V but given the close proximity of the actually RPi Zero board I would not recommend going above 30V. The relays are easy to select via GPIO headers and they use 3-way Screw Terminals.

You’ll find them on our Tindie store real soon.

MiniPiio PCB (Batch #2) board’s arrive

August 8, 2012

We received our second batch of PCB’s from our manufacturer today.

In the package were 4 sets of blank PCB’s for the MiniPiio boards: MiniPiio_RS232 (v0.2) , MiniPiio_ULN2803 (v0.2) and two new board MiniPiio_Relay2 and MiniPiio_293D.

MiniPiio_Relay2 is a two relay board with dual change over relays and MiniPiio_293D is a Full-H Bridge motor controller based on the venerable 293D chip. More details to follow.

Arduino PLC Shield Schematic v0.10

May 24, 2010

I’ve managed to find some time this week to put together a draft schematic for the PLC shield.

I’ve only included 4x opto isolated inputs as I happened to have some TLP521 Quad Opto’s handy. I’ve added a couple of extra analog inputs as I may used a Seeedstudio v2.12 Arduino clone and that has an extra two analog pins so it makes sense to have them available and I’m still need to find a spare control signal to control the RX/TX enables for the RS485.

arduino_plc 0v10

An update can be found here:
Arduino PLC v0.20

Arduino PLC shield

April 28, 2010

I recently had a need for a simple digital controller something similar to a simple PLC (Programmable Logic Controller). I wanted to use the Arduino board I had but I couldn’t find any I/O shields that had the right mix of relay outputs (6) and opto-isolated inputs (6).

I know I could stack shields but the enclosure I had wouldn’t allow it. So I’ve put together a oversized (its a lot wider than your normal shield) Arduino PLC shield schematic which has 8x Relay channels and 6x Opto-Isolated channels and some analog inputs as well. The final number of relays and opto’s channels may change but I’ll post it and a PCB once it’s finished.

An update can be found here:
Arduino PLC v0.20