Category: JackAl board/display

Some details:

There are multiple files in the project. Only one file has a secondary file name of INO. This file contains the setup() and loop() functions and, therefore, all program control elements start in the INO file. All other files are CPP (i.e., C++) files. While this is different than some of you are used to, it brings two advantages to the party: 1) it allows for type checking across files, and 2) it allows for incremental compiles. This second feature can be a real time saver. Instead of compiling almost 400K of source code spread out over 19 files, incremental compiling causes the IDE to only compile those files that have been changed since the last compile.

Line number 4 in the JackAl.h header file contains this line:

  #define DEBUG

In setup(), you’ll see

#ifdef DEBUG

    Serial.begin(115200);

 #endif

In a few places you will also find:

#ifdef DEBUG

   Serial.print(“x = “);

   Serial.println(x);

 #endif

If you leave line 4 in the header file unchanged, the Serial object is compiled into the code which can be useful for debugging, like the Serial.print() lines above. If you comment out line 4, the Serial object is NOT compiled into your program, and all of the subsequent debug print statements are also not compiled into the program. This technique is called “scaffolding” and it allows you to “remove” debug statements without actually removing them from the code. Because you don’t have to retype your debug statements in the highly unlikely event your changes have a bug in them. This can be a real timesaver. You decide what to do with line 4.

Even if you’ve never programmed, you will eventually get tired of seeing Al’s and my names on the Splash screen. The Splash() function is in the INO file and feel free to change it to your own name and call. Note if you want to change something, you must have installed the Arduino IDE and the Teensyduino patch. Details are in manuals.

Jack, W8TEE

Al, AC8GY

Reference

Jack, W8TEE and Al, AC8GY have announced that QRP Guys is ready to take orders for the JackAl support board for the µBITX. A link to a list of its feature set, a video of it in action, and some photos can be seen at

http://hamradiodesigns.com/index.php/photos/

Note that the AGC implements both audio and IF AGC. The appendix to the manual shows a plot of its characteristics. DSP filters are available, including user-defined filters (CUST in figure below). A CW keyer and decoder are also included. The main screen looks like this:

The decoded CW can be seen along the bottom. (In all honesty, that is a guy sending almost perfect code at about 22wpm.  Jack is still playing with the decoder and expects some really smart user to make it much better. It’s got real possibilities as it is based on the FFT bin counts.)

QRP Guys is offering the JackAl board for $40 for the first 50 boards.

After those are gone, the price will be $50.

Shipping in the CONUS is $5 and DX is $15. This is what the JackAl board you’ll get looks like:

The board has all of the SMD’s mounted (including the Si5351 and the display buffer IC). The user does have to supply additional parts: A Teensy 3.6 and associated audio board (both from PJRC.com) and either a 5″ or 7″ TFT touch screen display (BuyDIsplay.com). You should also consider case size when you select your display size. (Note: BuyDisplay.com has actual sizes for each display and they are measured like a TV, so the case can be smaller than you think.)  If addition, there are some IC’s, connectors, audio isolation xfmrs, and header pins that most of you will want to add. The cost of these additional parts should be less than $15 depending on your junk box. The board with these in place looks like this:

The connectors are not required but, since you are also give about a dozen free I/O pins for experimenting, you may want to add them. (The yellow pins above are test points.)

The assembly manual can also be found on the website.

This is an intermediate to advanced semi-kit project. Our intention is to not only give the µBITX additional capability, but to serve as a platform for experimentation, which we hope you will share with the rest of us. You will have approximately 700K of flash and 200K of SRAM free for your inventive side to exploit.

Al and Jack already have some (software) extensions we want to implement. Note JackAl does NOT fix the harmonic or spur issues. However, our test µBITX’s right out of the box were well within spec for 80 and 40 meters and spot on for 20M (15M and 10M, not so much). If you have doubts about your µBITX, check it out. It could well be that your favorite band is within spec. If you don’t have a spectrum analyzer, check with members of your club or the physics department of your local high school,. junior college, or university. Most will be glad to help.

You need to provide your own Teensy.  The reason for ordering a Teensy without pins is that you will need to use header sockets with long pins on the Teensy so that the Audio shield can plug into the Teensy and the Teensy plug into the JackAl board. The Teensy pins do not have the header sockets and are difficult to change without damaging the Teensy.

Note that the power jumper on the bottom of the Teensy 3.6 also has to be cut.

Reference