PicoMite Memory Keyer
Assy & Setup Instructions (06-May)
Parts List (PDF), or
Parts List (coming)
Have you ever had a simple project idea that becomes an all-consuming affair? It was worth it, though, and the results are exhilarating!
I had recently dabbled in one of the larger CW contests and I’m by no means a ‘Big Gun’ operator. I was making enough contacts, though, such that sending an exchange over and over became pretty tedious. I do have a modern rig that includes message recording from keyer paddles and subsequent playback. The issue? Two sequential button presses are required on a menu-driven display: the first to arm the message readout and the second to start the message. I found myself not pressing the first button firmly enough and instead of that CW message going out, I was altering the rig settings. I realize that there are a number of computer-based Morse applications out there. My shack is already extremely cramped for space and is located at the limits of Wi-fi coverage, so I needed a simpler memory keyer solution.
What to do? By way of explanation, I’m a diehard homebrew enthusiast and a frugal one at that. I don’t often spring for a commercial product if I can build one for myself, so a ‘D-I-Y’ Memory Keyer seemed like just the ticket as I cast about for a new project. The way forward was unclear, though. I’m conversant with C/C++ in the Arduino environment and it was time for a change.
I discovered that the Raspberry foundation recently announced an offering dubbed the Raspberry Pi ‘Pico’. Its tiny single-board computer module measures only 0.85 by 2.0 inches (2 x 5 cm) and has some really interesting features. Free software for this device includes the MMBASIC interpreter and there’s plenty of memory space. With the interpreter loaded, it’s referred to as the ‘PicoMite’. Best of all, Raspberry is selling the Pico module for only about $4. I was hooked right there!
PicoMite Memory Keyer (PMK)
PMK Expansion Boards: "Shields"
"Shields" ... What a great way we have these days to extend a microcontroller board's capabilities and customize its features for a given application! Such is the case we have provided for the K1SWL "PicoMite Memory Keyer". The PMK already has a rich and flexible base hardware I/O -- meaning that it has pushbuttons, I/O jacks, LEDs, potentiometer, sound output and an incredibly powerful and inexpensive microcontroller that may be programmed using numerous languages to perform designated tasks. Now we literally add on top of all this a "shield" expansion board to provide hardware to allow hams the ability to customize all this power for their own projects and applications.
At this time we have three Shields available for this customizable expansion to the K1SWL PMK platform:
PMK Shield 1: Prototyping Board
PMK Shield 2: OLED-GPS-CLK
Provisions are made for adding an OLED display, a GPS receiver and the QRP Labs' Si5351 Synthesizer to the PMK for your custom hardware and software projects! Plugs into the Raspberry Pi Pico processor on the PMK base board and provides full access to all the used/unused pins for an inexpensive-yet-powerful projects for radio projects.
Pinheaders & receptacles for the Shields to mount on top the Pico controller
Purchase the PMK & Shields (bare
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