Re: UBITX Touch Control TFT Display



I use the following: HARDWARE

DISPLAY - Optimum size - 2.8inch TFT - I have tried several types and sizes from various companies - hit and miss. some work but poor clarity etc.

Having used the elegoo 2.8 inch  TFT Display with pen - from "amazon" has resulted in 100 percent working, clear, clean, crisp displays.
I have ordered 4 over time and quality is persistent. Price  around $15.00 shipped.  Best choice

Arduino Module : Atmega 2560 - Ebay is cheapest source at less then $10.00...  Any Atmega 2560 will work..
I have many different company modules and have found they all work great...

DDS module -  SI5351  module (not just the chip)- available from Ebay or Adafruit direct or amazon around $11.00

Female single jacks to solder to the rear of the Atmega....

I use this method to get access to the pins from the rear of the atmega 2560 as the front is facing the front radio panel with the display plugged directly into it.
There is no room to get access to the pins
I have done this on 3 rigs - bitx40 and 1 ubitx
This method minimizes the wires from atmega to the ubitx board.

You can also use an interface board which vu2spf has developed - he has the pics but no pcb for sale.

Jumpers - makes it nice a clean 
1 Jumper cable (2 pin) male to female for connection of sda and sdc from atmega to dds Si5351
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

I feed the rig with 13.5 volts - well filtered non switching powersupply

I also use 2 buck voltage adjustable down converters (around $1.50 each ebay)

For 1- -- I  feed the 13.5 volt to it and adjust it down to 9v volts to feed the atmega 2560 - keeps it cooler than running full input voltage
I also add 2  filter caps -  one 2000 mfd caps on the input the other on the output along  with a 2- 10 ohm resistor on the ouput in series to act as a filter and hash filter isolation.

The second converter is used to feed the SI 5351 module - I adjust it to 5 volts - same filters as for the first   - keeps the unit isolated and cuts noise.

This results in a very quiet rig and everything nice and cool.

Not required but has not failed me in 3 bitx an 1 ubitx rigs... rigs always result in a quiet rig..

I will send pin diagram next go around

Code will be available in a few weeks - 

ABOVE - rear of the atmega - black plastic to hold atmega and cables and connectors added

2 buck down voltage converters - with blue leds

rear left of atmega with added single line female connectors top and side and bottom


You probably will want to install a pop click fix - Eliminates a loud pop / click whenever tx is turned on and off.

uses 1 1n4148 diode, a 470k resistor, a .22 cap and a 2n7000 mosfet......  Works amazing.....well.

This just mounts on the rear of the volume pot
above is view of mod - disregard the 104 cap.. this uses a bs170 but i use a 2n7000 - pin out is a little different
The pic above displays the raduino connection but works with the atmega t/r pin as well( red wire was raduino connection but i use the atmega 2560 t/r
pin 26 (ubitx)

my values are 470k and .22uf cap with a 2n7000 mosfet

This should get you going......


On Fri, Jan 26, 2018 at 8:46 PM, AA7GW <> wrote:

Sent from my iPhone

On Jan 26, 2018, at 3:23 PM, Brien Wankel <brien@...> wrote:

Looks great! Any interest in providing some sort of "how-to" and code for guys like me who want to do this as well?

- Brien K7XPO

On Fri, Jan 26, 2018 at 3:14 PM, Joe <joeman2116@...> wrote:
Finishing up the case for my UBITX
The display provides full touch control along with physical optional buttons.
100 memory channels
Tuneable Bfo
Vfo A B M
All bands selectable from front display
Uses cheap tft touch displays i use a 2.8
Low cost - Atmega 2560 for lots of pins and better perfomance.
Si5351 for dds

More to come.......

Coded by VU2SPF 
Tech support VE1BWV


First phase nearly completed

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