“The 16×2 LCD (or 1602) is a generic display and there are clones of clones of clones for this display. Who built it first has long since been lost to the mists of time, as has pretty much everything from the 1980’s. But hobbyists have taken to it because it’s cheap, and speaks via 5v logic just like the equally ancient tech of their Arduino boards. So they still get cranked out, by manufacturers too embarrassed to put a name on them. The going price on eBay is down around $1.60.”
The dimensions shown on page 16 are 24.1 x 72.2 mm.
Those pre-preparing a front panel while awaiting the arrival of their µBITx are advised to make a hole smaller than these dimensions, just in case the dimensions don’t match. There is quite a bit of variation in 1602 display dimensions.
Mike WB8VGE claims, “mounting any LCD on a front panel is a pain”. Probably most constructors would agree. Here’s how Mike does it without drilling holes in the corners to hold the display.
After you have painstakingly cut and filed the panel to allow the display to fit, fasten four .250 aluminum standoffs, one on each corner, and tighten with the correct screw. Use the shortest screw you have.
Check fitment and if necessary file away any panel material that might interfere with the display.
Using a sharpie pen, mark the corners. Don’t worry about being accurate, just a general location of each standoff will be enough.
Remove the display.
Use a bastard file and scratch around the area you just marked. The idea is to rough up the material.
Now, mix up a small batch of JB Weld.
Apply a generous amount to the bottom of each standoff, trying not to fill the hole up. (that’s why it’s best to use short screws so you don’t epoxy the screw in!)
Mount the display and with clamps, clamp the display onto the panel. I use small Irwin clamps and wood paint stirring sticks.
Wait 24 hours.
Whoa! You’ve mounted the display without trying to locate the mounting holes and without drilling holes!
Unless you go in there with a channel locks, you’re not going to be able to break the bond between the epoxy and the aluminum.
Tom AB7WT has also tried this out. He used shorter standoffs and put the JB weld on screws instead of longer standoffs. This way he could still unscrew the standoffs. It worked well and the screws were solid. The display and bezel look nice.
For those who are not familiar with wsjt-x, this software is a general purpose graphical user interface (complete with waterfall display) for digital HF modes. The software is a great product, and is available in Windows, Linux, and MacOS flavours to cover every amateur operator’s PC set up. What is more, if you have installed KD8CEC’s V1.01 uBITx sketch, this includes Hamlib CAT functionality so WSJT-X will work with your uBITx on all of those digital modes.
So what is WSTJX-Portable? This is a modified version of WSJT-X that is designed to be used on a Raspberry Pi and a 3.5″ TFT touch screen.
Did you want a nice compact touch screen for your uBITx, but don’t want to hack your uBITx enclosure and push your Arduino Nano to the limits? Then here is the answer! The uBITx is controlled by the Raspberry Pi via the 3.5″ touch screen. You can dial up a frequency, set the step value, change band or mode, go to TX or RX, etc. right from the touch screen. Quite a feat!
Vic WA4THRI always enjoy seeing how others have built their BitX’s and has pointed out ideas that others might find useful:
1. Almost everyone places their tuning control to the right, but if you place the Raduino to the right you can easily update and play with the software by just plugging your computer into the USB port [EDITOR: With a penetration on the right hand side wall of the enclosure for insertion of a mini-USB-B connector.]
2. It is hard to beat the value of the Banggood EF01 instrument case. If you turn it upside down and eliminate attaching the hard plastic feet you have a smoother mounting surface for circuit boards and can use the vent holes for a speaker grille. Add some stick-on soft plastic feet on the “new” bottom.
3. Using the second line of the BitX display to label switches and controls saves having to find a way to place labels on the front panel.
Andy KB1OIQ has posted a file on the [BITX20] IO Group files page: kb1oiq_i2c_mod.pdf that describes the hardware and software modifications that he performed on his uBITX to free up digital pins on his arduino. You will need to be logged in to the Group page to access the file.
Andy converts the LCD to use the I2C bus, thus freeing 6 Arduino digital pins for other uses. Only very minor modifications are required to the Raduino sketch (and you will need to install a different library). He documents every step involved with photos. Well done!
[EDITOR Comment – removal of the two pull-up resistors on the additional board and direct connection to the I2C A4 and A5 ardunio pins should suffice without use of a level converter board. However, the cost of adding in the level converter is negligible and will work well!]
Fred W4JLE writes that he has just discovered the NEXTION display and he has begun using it on his BitX.
He says “what makes it really neat is the software that can be downloaded from the manufacturer’s site. It takes all the pain out of graphics programming. I have replaced the UNO with an STM32 as in addition to the normal stuff I have added a GPS module.”
The display shows time/location/grid square data as well as using the 1PPS in the GPS module to do a continuous correction to the SI5351a oscillator. The higher resolution allows calculating the SWR etc. with much finer gradations.
Fred says he will be adding a filter board from a CODAN that will allow all band operation which he purchased for $12.00 on eBay.
Fred’s concluding comment is that it is “Amazing what is available to the homebrewer today!”.
We are eagerly awaiting a link to his sketch and to see photos of his uBITx!
The first uBITx has appeared with a 2.8” TFT display. The hardware is from Joe VE1BWV and the software from VU2SPF.
The display provides full touch control along with physical optional buttons. 100 memory channels come standard, along with a tunable BFO, selection of VFO A, B or M. All bands are selectable from the front display which is a cheap 2.8” TFT touch display. Joe uses an AT Mega 2560 processor for lots of pins and better performance and an Si5351 for DDS.
Further details were given subsequently by Joe VE1BWV …
We have already done this for the Bitx40 and released software, videos etc.
Under youtube vu2spf and facebook as well as in the [BITX20] io group.
They are for the Bitx40 but the new code for ubitx has all the same features.I have 2 of my 3 Bitx running the basic same code. They work and look great.
This has info on the code, features, hardware, etc. The full UBITX info will be posted soon, including the arduino sketch, hardware options, where to source parts. An article in QRP magazine has just been released to subscribers.
Joe recommends the Elegoo 2.8 inch TFT Display with pen fromAmazon.com. He has ordered 4 over time and the quality has been consistent, resulting in all of them working with clear, clean, crisp displays.
The price is around $15.00 shipped within the USA. Note that the vendor does not ship outside of North America.
Arduino Module : Joe uses the AT Mega 2560 and suggests Ebay is the cheapest source at less then $10.00 with any AT mega 2560 working.
DDS module – SI5351 module (not just the chip)- available from Ebay or Adafruit direct or from Amazon.com for around $11.00.
Joe uses female single jacks to solder to the rear of the At Mega. Access to the pins is from the rear of the atmega 2560 as the front is facing the front radio panel with the TFT display plugged directly into it. There is no room to get access to the pins after assembly. This method minimizes the wires from AT Mega to the ubitx board.
You can also use an interface board which VU2SPF has developed – he has the pictures, but no pcb for sale at present.
Jumper cables are as follows:
1 Jumper cable (2 pin) – male to female for connection of SDA and SDC lines from AT Mega to the Si5351 DDS.
1 Jumper female to female 8 pin from atmaga to ubitx board
3 cables for the clocks from Si5351 to the Ubitx. – shielded cable is best
Joe feeds the rig with 13.5 volts – using a well filtered non switching power supply. He also uses 2 “buck” converters (around $1.50 each on Ebay).
The first of these gets fed the 13.5 volt, and reduces the voltage to 9v to feed the AT Mega 2560. This keeps it cooler than running full input voltage. He also adds 2 filter caps – one 2000 mfd capacitor on the input side, and the other on the output side, along with a 2- 10 ohm resistor on the output in series to act as a hash isolation filter.
The second converter is used to feed the SI 5351 module, adjusted to 5 volts. This uses the same filtering system as above.
Joe says this results in a very quiet rig with everything nice and cool.