Teensy 4 arrives

PJRS, the makers of the Teensy family, have just added the Teensy 4.0 to their processor line up.  Jack W8TEE says, “It is a beast!”.  Perhaps he his contemplating an update to the JackAl board for the µBITx?
Some features of the Teensy 4 include:
– ARM Cortex-M7 at 600 MHz
– 1024K RAM (512K is tightly coupled)
– 2048K Flash (64K reserved for recovery & EEPROM emulation)
– 2 USB ports, both 480 MBit/sec
– 3 CAN Bus (1 with CAN FD)
– 2 I2S Digital Audio
– 1 S/PDIF Digital Audio
– 1 SDIO (4 bit) native SD
– 3 SPI, all with 16 word FIFO
– 3 I2C, all with 4 byte FIFO
– 7 Serial, all with 4 byte FIFO
– 32 general purpose DMA channels
– 31 PWM pins
– 40 digital pins, all interrrupt capable
– 14 analog pins, 2 ADCs on chip
–  RTC
 The footprint is actually smaller than the Teensy 3.6 and the cost is, too…$19.95.
This processor is overkill for many projects, but the depth of that resource pool opens a whole new world in many arenas!
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Cheval Case with JackAl board installed

Rick KN4AIE installed his uBitx V3 in a Cheval case (see previous post) and later added the JackAl mod.

Everything fit nicely.  The case is all aluminium and easy to work with.  It also provides very good access with both top and bottom covers and front and back  panels removable.  The case is a little pricey, but very nicely constructed.

Rick ordered his case from an eBay seller.

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JackAl revised wiring harness instructions

Jack W8TEE has taken a number of steps back and reexamined the documentation for the JackAl wiring harness .   You can access the new instructions for assembling the harness by clicking on the reference link below.  Al has added a bunch of new photos to go with the written instructions.  Hopefully constructors will find the instructions to be much clearer.

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Caution for JackAl Board owners

Jack, W8TEE and Al, AC8GY produce the JackAl Board add on for the µBITx.  They are warning that two JackAl owners have reported that a voltage spike destroyed their RA8875 display.

Al has looked into this and found that there is a very narrow voltage window on the display. Buydisplay confirms that 4V on the 3.3V line can ruin the display. From what we can determine, voltage spikes were the culprit in both cases.

What the JackAl team is doing is creating a very small PCB that will clamp the supply voltage to the display. Parts for the board will cost less than $2.

They will send one of these PCB boards to JackAl owners at no charge with a request and a SASE.

Further details will be provided when the boards come in.  Jack and Al are also expanding the documentation and hope to have a new assembly manual shortly.  Announcements will be made on the BITX20 IO Groups list and this article will be updated accordingly.

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uBITx v5 Board compatibility with JackAl

 

Jack, W8TEE and Al AC8GY have spent considerable time testing a couple of V5 µBITX boards for use with their JackAl board.  No hardware modifications are required when using their board with the v5 µBITx.

However, Jack is making some minor changes in the software because of the new IF frequency.  They expect to release a new software release for the V5 board in a few days.  They are also expanding the assembly manual with additional photos and narrative.

The JackAl boards are being sold by QRPGuys.com.

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JackAl

For those who are not following the email list, during the gap in coverage on ubitx.net in January, Al and Jack launched their JackAl board that adds a lot of features to the µBITx.

The hardware is compatible with the µBITx v5 board, but requires different firmware.   More details on JackAl will be added to the website with a January posting date shortly.  Check back in the list of posts, as I am backdating information to provide a better history for constructors visiting the site.

Jack is going to be at Hamcation in Orlando. If you see a shirt with the picture of the JackAl display on the back at Hamcation,  then stop and say “Hi!” to Jack W8TEE.

Reference 1
Reference 2

Source code for JackAl

The source code for JackAl is now available for download at our web site, hamradiodesigns.com. I apologize for the delay and that delay is totally on me. Al had his work done months ago. In my defense, it not easy to get 11,000+ lines of C/C++ code to play nice with each other. That said, we think the final result is worth the wait, with features we think everyone will appreciate.

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.

This code is Open Source, as is the hardware. This is an experimenters platform and we hope you will do just that. That said, we ask that you leave the file header comments unchanged and at the top of the file. Feel free to add whatever you wish after our comments.

There is a JackAl group now (https://groups.io/g/JackAl) and all comments, questions, and support will be done via that Forum. Please check the site from time-to-time, as we know we want to improve a number of things in the software.

Jack, W8TEE

Al, AC8GY

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New JackAl IO Group

 

Jack, W8TEE and Al AC8GY have formed the JackAl Group for those who may be interested. Because JackAl is an add-on board for the µBITX, we designed the board to be an experimenters’ platform.

While JackAl does use over 200K of flash memory, its processor (a Teensy 3.6) scoots along at 180MHz and leaves about 780K of flash and 230K of SRAM free for experimentation and you still have about a dozen I/O pins to experiment with, too.  They are also using the PJRC companion audio board to augment the DSP that JackAl supports.

Those who may be interested should visit the site:

JackAl groups.io Group

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Differences between the JackAl and Nextion displays

Most people don’t understand and won’t want to understand the differences between different types of display technologies.

Unfortunately,  the µBITx community has fractured its user base amongst competing screen technologies.   There are many different types of LCD display screens and they are not compatible at all.   

Differences between the Nextion and JackAl displays have been discussed on the BITX20 IO Group list following discussion about whether a Nextion screen used with the KD8CEC firmware could be ported across to the JackAl.  The simple answer is “No”!

Brian N8BDB notes that  it’s not going to be as simple as replacing a driver and rebuilding the application.  The Nextion display works in a very different way than the normal displays most people use for microprocessors like arduino and teensy.

Normally the display is a “dumb” device that just handles displaying the dots.  Software libraries are used to provide basic functionality like drawing lines, boxes, and text.  Touch events are handled completely separately by other libraries.

The Nextion display is the opposite.  The display has it’s own microcontroller, memory, etc. and the arduino communicates with it through a serial interface.  All of the buttons, text, gauges, etc. are prebuilt in the Nextion editor.  The application doesn’t know where they are on the screen.  It just has a name such as “button1” that is associated with a button on a particular screen for instance.  The application just sends a command to the display to change the text of “button1” to “abcd”.  It would require a significant rewrite of the JackAl UI code to make it work with a Nextion display.

The other thing as Jack pointed out is about resolution.  The Nextion displays most people have are much lower resolution than the display used by the JackAl board.  The 2.4″ and 2.8″ Nextion displays are 320×240.  The 5″ Nextion display ($60) is the closest one with similar resolution (800×480) and that is 33% more in price than the display ($40) that JackAl currently uses.  Even the 4.3″ Nextion display is only 480×272.

There are pros and cons of both screen types.  The Nextion costs a bit more per pixel because it has a processor on board, but the demand (in terms of memory and processing power) on the main µBITx is minimal.   The processor and screen communicate using a series of codes.   The Nextion (in theory) can be adapted to have quite different user interfaces for the same functions.  There are, in fact, at least two distinctly different versions of “look and feel” available already.   However, setting up these requires a fairly steep learning curve on the screen management environment.

On the other hand, the JackAl screen (along with all other types of LCD screens) is strongly tied into the firmware of the JackAl teensy processor and amending the “look and feel” of the display requires detailed knowledge of the processor, firmware and the screen programming environment on which the JackAl is built.  It is unlikely that the Nextion will be ported across to the JackAl environment any time soon.  Bite the bullet and buy a new screen!

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Jackal Board for the uBITx released

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.

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