[volt-nuts] TASS Computer-Controlled Switch System
John Ackermann N8UR
jra at febo.com
Sun Sep 27 10:19:52 EDT 2015
Every so often, I hijack the list to do some shameless self-promotion
when I think it would be of interest to the 'nuts community.
I've spent the last several months developing a computer-controlled
relay switch system. The impetus was failure of the old HP 59307A GPIB
switches in my PPS measurement system and discovery that replacement
relays are unobtainium. The only similar remote switches I could find
cost >$1K, which seemed a bit rich. So, I decided to roll my own.
We ended up with an 8 port switch board controlled by an Arduino. I
think it will have lots of T&F applications as well as usefulness in ham
shacks. Like virtually everything I do, it ended up as a TAPR kit.
There's an introductory video at https://youtu.be/P-TUM2dOi4c
The relay board kit is $119 and we have a shield for the Arduino Mega
2560 that can control 4 relay boards and costs $19. The software is
open source.The boards are now available from TAPR at
(BTW, I contribute my designs to TAPR and don't have any financial
interest in sales.)
Special thanks to time-nuts Bob Camp and Tom Holmes for a lot of
Here's the TAPR product announcement:
Now Available: The TASS Computer-Controlled Switch System
The TASS (Totally Awesome Switch System) is a general purpose 8 port
DC-150 MHz relay-based switch. The hardware is designed to be very
generic, with an inexpensive processor such as an Arduino providing the
system logic. Control is via USB, with ethernet and other interfaces
The TASS can be configured several ways, and multiple boards can be
combined to create large switching systems. The TASS has many uses, from
switching signal sources on a test bench or in a laboratory, to
selecting receive antennas and filters in a ham or SWL station.
The TASS system has two boards:
* The TASS-R relay board, which does the mechanics of signal switching
and provides a very simple 10-pin interface.
* The TASS-SHIELD board for use with an Arduino Mega 2560
microcontroller. The TASS-SHIELD allows up to four TASS-R boards to be
Both boards are available now from TAPR as kits. They use through-hole
parts and don't require any special assembly techniques.
The final component is open source software for the Arduino that acts as
an interface between a host computer or other input system, and the
switching hardware. The software is available for download from TAPR.
An introductory video is available at
or from TAPR at
Software and documentation can be downloaded from
You may order the TASS-R and TASS-SHIELD boards by visiting
More information about the volt-nuts