The first TFT display for 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.

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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.

See http:// vu2spf.blogspot.ca

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.

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Joe recommends the Elegoo 2.8 inch TFT Display with pen from Amazon.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.

The Elegoo 2.8″ display with ATMega 2560 mounted behind it in the uBITx

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.

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