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Digital LO / BFO for the ZIA rig!

 

The 128X160 ST7735 Color TFT.


The 1st Step in the Resurrection Process is to build a replacement LO/BFO and that was done yesterday.

I had mentioned this project started on the wrong foot with a Black and White Nokia display and was quickly replaced with the ST7735 color display. However, that ST7735 was a 128X128 thus going to the larger 128X160 required extensive software changes to fit the old code on a larger screen. 

I put two LO's in the code so with a flick of a switch one could check for band activity on FT-8. That is a quick test as often the band seems dead, but a listen at FT-8 will show the band is alive and open to DX. As usual this code has LO memory.

BTW smack dab in the middle of the screen is a teeny tiny frequency readout with a small green dot. The plan is to include in the code -- split operation and that would show the transmit frequency. That is not fully operational as yet but certainly on the to do list. Try that with your analog VFO. 

Those with a super keen eye will spot what appears to be an open "blank" space right below the small frequency readout and to the left of my call sign. Well, it is not blank as built into my code is a timed 1kHz audio pulse train of about 7 seconds for Tune Up purposes. Hitting the momentary PB starts the pulse train which is fed into the balanced modulator and in the blank space appears the word "TUNE". You will not find that functionality in a Bitx rig!

The Green dot under the "A" is to show that is the active LO. Switching to "B", The "A" dot goes dark and a similar dot under the "B" goes from dark to Green. Yes, a simulated LED lamp.

I discovered yesterday that the original front panel must have been cut from a custom piece of PC board as it is slightly longer than 6 inches. I have nothing longer than 6-inches in stock so there will have to be a major rework of the original panel to accommodate the larger Color TFT. That is today's task.

Them that know can make things go.

BTW got a new batch of Nano V3's and these use the USB "C" connector. I also have been using a recent upload of the latest Arduino IDE. Finally, functionality that eases the pain of loading code and it is backward compatible with sketches written 10 years ago. Bravo Massimo Banzai!

73's
Pete N6QW

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