Review: Open Keyer


The Open Keyer is a cute little keyer kit that is Arduino based and runs my open source keyer software.  It features a menu button, three memory buttons, a speed control, a PS2 keyboard connector, and a USB port.  The unit can be powered either through the USB connector or an internal 3 AAA battery pack.  A 1/8″ (3.5 mm) stereo jack is provided to connect your paddle and two phono connectors are for keying your transmitter key and PTT lines.

The brains inside the box is an Atmel ATMega chip running the Arduino bootloader, along with a USB chip.  Essentially it’s an Arduino and the normal Arduino development IDE can talk to it and program it.  As mentioned before it’s intended to run my open source keyer code, but it can be used with any Arduino code including your own keyer implementation. If you don’t need a PTT line for your transmitter, you can easily modify the source code to use the PTT port and a second transmitter keying port.

Most of the circuit is surface mount technology (SMT).  I hadn’t soldered SMT components for several years.  Last year I got my first set of reading glasses, and I found myself cursing the little parts, which in my more youthful years I’d have no problem working with.  This is no fault of Hamshop, just me whining about my age.  Luckily Hamshop pre-installs the ATMega and USB chips, so the most difficult components are taken care of for you.  The enclosure is a very simple but effective extruded aluminum two-piece clamshell or channel with two end pieces for the front and back.  Vinyl decals are provided for the front and back, and an instruction decal is provided for the top.  (Although my callsign is on the front of the unit, note that I did not design the hardware or kit.)


The unit performs well, though I accidentally left it on battery power for a few days and totally drained the batteries.  This prompted me to add a sleep mode feature to my code which is in beta testing and should solve this problem.  One minor issue with the Open Keyer kit is the front speed knob.  On my unit it does not fit well, with not enough of the potentiometer shaft exposed for the knob to grab on to. Ondra, OK1CDJ, at Hamshop tells me that they’re adjusting the alignment of the potentiometer in the next revision to address this problem.

I won’t review the actual keyer software as the documentation for this is here, and naturally I’m a bit biased about it, but it does about anything a CW aficionado would want to do.  All in all the Hamshop Open Keyer is a nice little kit that can be assembled in an evening or two, and is reasonably priced.

(Full disclosure / disclaimer: I do not have a financial interest in Hamshop, and I can’t provide support for this keyer hardware.  Support for the open source code is available on the Radio Artisan discussion group.)

Anthony, K3NG, is a regular contributor to

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