Arduino Using A Straight Key For Morse Code Assistance


For those unfamiliar with Ham Radio, there are lots of fancy tools these days to make it easier for the radio operator. But enthusiasts still like to get back to basics, and one way to do this is to participate in Straight Key Night. This is when you pull out your traditional Morse code keyer and have a chat with others around the world. The most recent event was on New Year’s Eve. The only drag is that it sometimes takes a while to find another Ham who’s listening, and this can mean repetitively keying the letters QC SKN for long periods of time (QC invites listeners to respond, and SKN is to inform them you’re participating in Straight Key Night). Sure, a programmable keyer will do this for you, but that is against the spirit of the event. [Mike Herr] found a grey area by mechanically interfacing an Arduino with a straight key.

You can see the straight key being pressed by a hobby servo in the image above. The servo is driven by the Arduino, which will transmit the series of letters automatically. As you can see in the video after the break, once [Mike] hears back from a fellow operator he switches to a huge wooden straight key for the rest of the conversation.

[thanks William]

28 thoughts on “Arduino Using A Straight Key For Morse Code Assistance

  1. CQ invites a response, not QC. Amateur radio prohibits broadcast, except in the case of beacons (which are used to gauge ionosheric / atmospheric propogation conditions). Thus, if you sit down, turn on your radio, and want to talk to somebody, you will send CQ repetitively until someone answers or you move to another frequency and try again. Typically something like “CQ CQ CQ , CQ CQ CQ “. Morse operators (abbreviated CW) have a number of shorthand conventions (prosigns) as well, so the CW CQ calls can be a little more dense. I haven’t worked CW in years, so most of it escapes me – but i do recall that when a phone (voice) operator is participating in a contest, he may call “CQ Contest” or “CQ Field Day”.

    1. Usually there’s a “DE” (French for “from”) before the call sign. As in “CQ CQ CQ DE AB0VV”.

      As for the project, I don’t buy the claim that using a servo eliminates any ethical problem. Might as well switch a transistor in parallel with the keyer. Not my place to judge whether it is right or wrong, though – I haven’t used Morse Code on the air for decades.

      73 DE AB0VV

      1. There isn’t really a set rule as to how you do it but normally voice is:


        You can easily mix it up no problem…….
        Example if your on 10 meters a lot of people do

        CQ 10 CQ 10 this is CALLSIGN calling CQ CQ CQ

        Over CW/morse code many people call as


        As noted broadcasts are not authorized unless your a beacon (this includes APRS)… Other wise when your trying to communicate with someone your actually “transmitting”

  2. The whole point of the straight key night is to AVOID using computerized or even mechanical help in sending the code. Though I don’t know of any hard and fast rules, this sure seems like a violation of the spirit, even if it’s creative, hack-worthy, and technically ends up using a straight key connected to the transmitter. A experienced operator can hear the difference in the timings of dits, dahs, and spaces between them. A human operating a straight key can try to keep a steady speed, but will never match the precision of any of the automated assistants commonly used.

    Is this Arduino sending out its CQ message using automatic, precisely generated dits and dahs? Or is it repeating a version that was recorded by a human using a straight key, with all of the human imperfections? The latter would at least sound more like a straight key.

    73 de AG6QR

    1. “a programmable keyer will do this for you, but that is against the spirit of the event”
      so, in effect, he made a programmable keyer. I’m with you that this is against the spirit, but I can still appreciate not wanting to tap for hours on end waiting for a response.

      1. I don’t see it as *too* much of a violation of the spirit provided you’re not using it past making the initial connect. Been a while since I’ve done CW (or radio of any sort for that matter) and SKN seems like a fun way to get myself to do it again. However, there’s only so much to be gained by manually sending out a metric assload of CQs until you get a hit.

    1. Just for the fun of it!
      It’s almost not breaking the spirit of straight key night either, since he is using a key in the build.
      Bit it’s done with that glimpse in the eye

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