Skip to main content

USB Morse Keyer

USB Morse Keyer is a microcontroller-based auto keyer project with following features:
  • USB / straight key / iambic key inputs.
  • Support for both standalone and USB operating modes.
  • 64-character USB typeahead buffer and 6-character Morse key typeahead buffer.
  • Support 5, 10, 15 WPM.
  • 6-page message memory.
  • 1W Audio output.
  • Audio and PTT output interfaces.
  • 32 character display 

Final view of the USB auto keyer.

The USB interface of this unit is designed to work with most of the operating systems. It emulates a virtual serial terminal to transfer keystrokes to the keyer. In most of the operating systems, this interface works without installing any additional device drivers. To submit keystrokes user can use any serial terminal software such as PuTTY, Hyper Terminal, Minicom, etc.

This keyer is designed to work with 7V to 16V DC input voltage. The most recommended working voltage is 9V.

The bottom side of the USB auto keyer.

To reduce the dimension of the PCB this unit is designed with combining both through-hole and surface mount components. To facilitate future upgrades and modifications, the PIC16F886 MCU sticks with the standard 28-pin DIP package.

This is an open-source hardware project. All the design files and firmware source code are available at the project repository at github.com. The project documentation with all the details which including assembly details, firmware uploading, compilation, and usage instructions are available at the project repository's wiki.

Comments

Popular posts from this blog

Building the TD4 4-Bit CPU

The TD4 is a famous 4-bit CPU featured in the book How to Build a CPU by Kaoru Tonami . The book focuses on constructing a functional processor entirely from basic 74-series TTL logic ICs. While the book is unfortunately only available in Japanese, a friend from Japan sent me a copy along with a TD4 PCB. I believe the PCB is based on the open-source design files available on BG5DIW's GitHub repository . "How to Build CPU" book and the PCB. Recently, I finally found the time to build and experiment with it. The project took a few months, as I had to translate the book myself to grasp the core concepts. The overall design is simple and elegant, offering a set of 12 instructions and a 16-byte ROM (implemented via DIP switches) for programming. The board operates on 5V and can be powered via USB. Most components were sourced from local shops, though I had to order a few 74HC-series ICs online. Later, I tested the circuit by replacing some 74HC components with 74LS series...

CD2003 - yet another simple FM radio receiver

In the last few days, we are looking for some simple FM radio receiver to integrate into one of our ongoing projects. For that, we try several FM radio receiver ICs including TDA7000, CD2003/TA2003/TA8164, CXA1019, and KA22429. Out of all those chips we select CD2003 (or TA2003/TA8164) based receiver for our project because of its simplicity and outstanding performance. Except to CD2003, Sony CXA1019 also perform well but we drop it because of its higher component count. We design our receiver based on Toshiba TA2003 datasheet and later we try TA8164 and CD2003 with the same circuit. Either CD2003 or TA8164 can directly replace TA2003 IC, and as per our observations, TA8164 gives excellent results out of those 3 chips. A prototype version of CD2003 FM radio receiver The PCB design and schematic which we used in our prototype project are available to download at google drive (including pin-outs of crystal filters and inductors ). Except for CD2003 IC, this receiver consist...

AVR-HV: High voltage programmer for AVR microcontrollers

When it comes to AVR microcontrollers the most common programming option is In-System Programming ( ISP ). ISP interface is easy to use but in some scenarios it is totally unusable. The most common scenario is with some wrong fuse bit values. For example if we program SPIEN or RSTDISBL fuse bits, AVR microcontrollers may not respond to any in-system programmer(s). To overcome these problems the next available option is high voltage programming mode. In High voltage programming mode, 12V programming voltage is applied to RESET pin of target AVR microcontroller and user can change configuration fuses of AVR MCU with minimum amount of risk. The only drawback in this mode is that target microcontroller must need to be removed from the board to reprogram. Most of the AVR high voltage programmers are expensive and difficult to find in ordinary electronic shops. As a solution we implement USB base high voltage parallel programmer for AVR microcontrollers and it allows programming, readi...