A flexible and reusable microcontroller project allows you to run ham radio experiments specified in the PIC Elmer 160 course. The PIC-EL is currently available as a partial kit (pcb+limited parts) from the AmQRP Club.
The AmQRP “PIC-EL Kit” is a multi-function PIC16F84A-based project board that serves as the basis for the experiments being conducted by John McDonough, WB8RCR in the online PIC Elmer 160 course. The course material is geared around use of common I/O components — pushbuttons, LEDs, LCD display, rotary encoder and speaker — and the experiments are designed to take the student through a step-by-step creation of software programs that beep, display and otherwise interact with the user in an instructional manner.
Further, the PIC-EL project board contains an integrated, built-in serial programmer that allows the user to download new programs directly from the PC and “burn” them into the PIC microcontroller … without requiring any other specialized programming hardware! Thus whenever you make a change in the software source code on your PC, by following the course material or if making your own original program, all that’s needed to program the PIC device is to connect the board to the PC with a standard 9-pin serial cable, like one from Radio Shack (p/n 26-117B).
We designed the PIC-EL project board with the QRPer specifically in mind. Realizing that hams just love to generate RF and use it in all sorts of ways, we provided an ability for the user to plug in the inexpensive and ubiquitous DDS Daughtercard from the NJQRP Club. Some experiments downstream in the Elmer 160 course will provide software that allows the PIC to control the DDS Daughtercard to produce signals in the range of 1 Hz all the way up to 30 MHz. A rotary encoder “dial” provided standard on the board allows one to use the PIC-EL and a stable signal general, a super precise VFO or perhaps even as a signal source for receiver calibration. A BNC connector is also provided in the kit to help enable these common uses. PIC-EL designer Craig Johnson, AA0ZZ already provided a modified version of his popular DDS control software signgen3a that runs on the project board, making the kit immediately useful even while just starting the Elmer 160 course.
Can there be even more capabilities built into the PIC-EL project board? You bet! Not only can the PIC-EL generate signals, it can measure the frequency of an input signal to the BNC connector. Just change the position of an onboard jumper and you’ll route signals coming into the BNC jack over to a small circuit that conditions the signal so the PIC microcontroller can determine its frequency. Again using software developed in one of the Elmer 160 experiments, the PIC-EL board will serve as a frequency counter for your bench, displaying the measured signal on the LCD.
The exciting uses of the PIC-EL board continues with design team’s addition of a couple of 1/8″ stereo jacks on the board. With the right software being developed as course material by John McDonough WB8RCR, you will be able to plug in your iambic paddles (like the nifty ones being produced by the AZ ScQRPions) and have the project board serve as a keyer with adjustable speed, weighting and multiple memory buffers. The onboard speaker serves as a side tone for your memory keyer. Just connect the “keyline” output signal to your rig by cabling from the other 1/8″ jack and you’ll be able to key your rig with the PIC-EL project board. So once again, not only will you learn how to program the PIC to do this keyer function, but you’ll have a fully operational keyer for your rig on the bench!
The PIC-EL project board was designed to fit into a common 5.25″ x 5″ x 1.25″ plastic enclosure, such as from Radio Shack (p/n 270-214), Mouser (p/n 616-63049-510-039), or PacTec (p/n CM5-125). The board fits neatly in this clamshell case and the input/output jacks were layed out to be at the top and bottom of the pc board, and are thus able to protrude from the end panels of the case. Just take off the top part of the clamshell case when you use the project board, and hold it on with a rubber band when you want to store it away.
But wait, there’s more! The AmQRP design team also provided flexibility in the PIC-EL board layout to allow you to use an external PIC programmer, in case you already have a favorite one. By unplugging a single jumper on the board, you can effectively separate the programmer circuit from the PIC microcontroller and functional circuits. This allows you the to connect in your external programmer to the onboard PIC so you can use the same programming system that you’ve been using for years. Alternatively, you can also use the same circuit separation technique to allow the built-in PIC-EL programmer to connect over to another project board to program its PIC microcontroller. Program an external chip with the PIC-EL programmer, or use an external programmer to program the PIC-EL chip — either way, it’s flexibility deluxe.
The PIC-EL project board provides components that allow the radio amateur to follow along directly in the Elmer 160 course material, and perform many useful projects in the shack with the completed board. The PIC-EL Kit has provisions for …
- Socketed PIC16F84 Microcontroller
- RS-232 serial port programmer
- Pushbuttons (3) and LEDs (3)
- Miniature piezo speaker (500 Hz to 10 KHz)
- Rotary encoder (30 steps per revolution)
- 8-character liquid crystal display
- 1/8″ jacks (2) for connecting your paddle and rig
- Socket for the NJQRP DDS Daughtercard
- BNC jack for signal input and output
- Board size: 4″ wide by 4.8″ tall
- Power req’ts: 12-14V DC
- Assembly manual on CD-ROM