Jean-Luc F6HOY compares the uBITx transceiver with some old stablemates:
Jean-Luc concludes the uBITx is not too bad….
https://www.youtube.com/watch?v=bmH6Ow_DOiU&feature=youtu.be
An amazingly smart idea for extra I/O ports
Tom WB6B want to expand the number of digital and analog I/O pins available to him in adding enhancements to his uBITx.
He came up with an ingenious idea, by creating a Smart LCD Backpack to replace the commonly found ones on inexpensive 2×16 and 4×20 I2C displays found on eBay and Amazon.
He has uploaded a library to GitHub that allows you to program a Arduino Nano to emulate the common I2C to parallel backpack used on an I2C display (either size). The Smart I2C Backpack, additionally, allows you to read and write the analog and digital pins on the Smart I2C Display Backpack.
The package includes a interface library that you include in your code to interface with the Extended I/O functionally. Also included are two example sketches. One is the code you program into the smart backpack. The other is a demo/test program you program into another arduino and connected via the I2C bus to the Smart Backpack Display.
The Smart Display Backpack should work with firmware using standard I2C LiquidCrystal drivers such as the KD8CEC firmware.
The code uses libraries that are installable from the Arduino library manager,. The GitHub URLs are just for reference.
- SoftTimer.h //https://github.com/prampec/arduino-softtimer
- Also requires: https://github.com/prampec/arduino-pcimanager
- LiquidCrystal_PCF8574.h
The following libraries should be part of the base Arduino software install:
- Wire
- LiquidCrystal
Tom hopes that others will enjoy this new display and I/O expander.
And the link to the code …
https://github.com/mountaintom/SmartLCDandIOexpander_I2C
Reference
Adding the v4 pop fix directly to a v3 board
Nigel G4ZAL has added the v4 pop-fix to his v3 board by placing components directly onto the v3 board.
Instructions:
- Swap out R70 from 100 ohms to 1K.
- Drill a small hole (0.7mm or similar) to the right of R70 so as to be able to fix the 2N7000 transistor.
- Pin 2 of the 2N7000 is soldered on the underside of the board (ground).
- Scrape a little varnish from the tracks and tin ready to fix the 2N7000.
- Add some Kapton tape to stop any shorting of components.
- Add the remainder of the components and run a bit of enamelled wire to the trace near the Raduino headers to pickup the T/R line.
Seen from the front of the main board (ignore the cutouts on the front of the board)
Reference
Homebrew uBITx with through hole components
Peter M0HYT likes to do it the hard way. He has designed a circuit board layout with the Nano on board and stocked with traditional through hole components. You will see his new board photographed alongside a uBITx kit main board from HF Signals. It looks pretty stunning!
Download the design details:
[wpdm_package id=’2774′]
Reference
Getting prepared for the JackAl
Some of you are waiting with baited breath for the JackAl Board, announced by Jack W8TEE. You can get yourself geared up for the JackAl by pre-purchasing some of the kit required, as it is due to be released shortly. You will need a colour touch display panel, a Teensy 3.6 processor and associated Teensy audio board.
Display panel
There are two display options for the JackAl board: 5″ or 7″. Neither is likely to fit in your existing µBITx enclosure, so you may also want to purchase a new enclosure.
The panels can be purchased from BuyDisplay.com. Their order numbers are:
ER-TFTM050-3 (5″)
ER-TFTM070-5 (7″)
Both displays use the following options:
4-wire SPI interface
3.3V
Resistive touch
No font (the library is being used for fonts)
Both are 800×480 displays using the RA8875 chip. If you run the samples using a touch screen, make sure you run the Calibration sample program first.
Teensy 3.6 and audio board
The Teensy 3.6 and its associated audio board can be purchased from the manufacturer’s website or from other sources.
Reference
MicroSD reader extender
Rohn KR0HN was “parts shopping” online when he came across a microSD card extension cable.
This could be used to extend the microSD card slot of the Nextion display out to the exterior of the case. This would be handy for upgrades to the display firmware as new features become available for your display.
The link to the amazon page is: https://www.amazon.com/Extension-Extender-Flexible-Monoprice-Raspberry/dp/B072X27V58/ref=pd_sim_147_14
Reference
Dimming your Nextion display
Ian KD8CEC has been looking at power consumption on the Nextion display and how to effectively dim the screen for portable µBITx work, where you want low current drain.
The following picture show’s Ian’s display (2.8″ TJC Chinese version) at Full Power:
And the screen fed with a series 50 ohm resistor (1/2 watt rated or more):
The slightly dimmer display halves the current consumption from 89mA to 44mA with a series 50 ohm resistor (made up of two 100 ohm resistors in parallel (or 3 x 150 ohm resistors in parallel). The Nextion screen has a built in software dimming function, and this can be adjusted in Ian’s Nextion display firmware. However, the feature generates noise in the µBITx and is not recommended.
Resistor installation
Installing a series resistor (with a value between 20 ohms and 100 ohms) in the +5V power lead will cause the display to be dimmed, but function normally (except for use of the micro-SD card reader). The resistor could be installed across a slide switch or toggle switch (with one pole shorted and the other going through the resistor) to allow for two settings (normal, dimmed). This could be handy for night time or portable use. The circuit diagram for this is as below:
For further details see Ian’s website.
Breadboard uBITx
Jon Titus KZ1G shows off his breadboard construction technique, which he uses while his rig is under development. The board is mounted on a piece of plywood and usea 1/8-inch clear plastic as front and rear panels for controls and connectors. This “breadboard” technique has been used by Jon for other projects, because it lets him rearrange control locations, ensure clearances between components, jacks, heatsinks, etc. In this way he doesn’t ruin a nice front panel when later adding an extra pushbutton or switch, etc.
After learning about the W0EB and N5IB RadI2Cino (Rad I2C ino) project he needed more room for the replacement board and a larger LCD. A section of plywood was glued on the front (see photo) and the front panel was then able to be moved forward by about 4 cm. Jon quickly added an extra pushbutton, and drilled holes to mount the LCD.
However, when do you make the call to put the whole thing in a proper metal case Jon?
Reference
Evening up power out using KB1GMX and K9HZ solutions
Mike N6CMY has been doing some mods on his µBITx, including some of Allison’s mods by substituting 2n2222’s and a BFR106 for the 3904’s on the RF lineup (pre-driver and driver stages).
In terms of output power the results are impressive. But in terms of levelling up the output… well not so good.
Mike measured 12W on 10M and over 35W on 40M! He was a bit taken aback at this point!
He finally bit the bullet and used K9HZ’s multi relay/pot method for levelling the response.
Mike was reluctant to use such a brute-force solution for a subtle problem but he now measures 15W on 80, 40, 20 M and 12 on 10M. VICTORY!!
Reference
A fan for your uBITx
Arvo KD9XLC has put one of these 12v fans that cost less than a dollar on the back of his Excelway case from Bangood (which apparently now on sale for $8.88).
You could attach the fan to the cabinet with hot glue, or use the correctly sized bolts/nuts.
And if you don’t want those fans to run on receive connect them to the TX 12v line, namely at pin 3 on U2, which is what Arvo did.
