A hallmark of many of the current homebrew rigs is compact size aimed at portable operation and the ever-popular POTA / SOTA events. Half Size OLEDs used as an SDR Spectrum Display are a reality.
But going the other direction for those of us whose eyesight can no longer spot a 29A from a 44DD at a half a mile, then we need bigger displays. The next couple of postings will cover the use of larger displays such as those that employ the ILI9341 scheme. Note you can see the pixels on the display.
Feast your eyes on this display using the ILI9341. I should add that I have several of these displays ranging in size from 1.8 inches to 3.2 inches. The pinouts and the code are the same for either. This is the 3.2 Inch display.
ILI 9341 on a Rig
Resist simply taking your current display using the ST7735 wiring and "plug er in". You risk smoking something as the ILI 9341 Display inputs like to see no more that 3.3 VDC. Thus, you need a CD4050 level shifter or a simple voltage divider, to limit the input.
A resistive divider, a simpler approach is shown as connected to the Arduino Uno. But now crisis mode as you only have an Arduino Nano and so how do you wire that.
There is no connection to Pin 9 on the Display.
My P3ST rig which I think can still be purchased from K7TFC as a kit was never moved from the wooden breadboard and it looks like hell! So, moving to the ILI9341 will not only give me a display that is easier on the eyes. It will also be a chance to make the 7-transistor rig look uptown.
But this is just a start as the initial Hybrid Wireless code was for a single frequency display. The next steps will add in two frequencies with memory and the tune up tone. The original use of the 3.2 Display was on the Hybrid Wireless that had a 12AV6 tone oscillator.
The 1st task is to build a new digital LO/BFO with the ILI9341 and then add the changes mentioned. Something that caught my eye early on was that even though the display was much larger the frequency changes seemed seamless and smooth. There did not seem to be a latency of you move the tuning knob and you await the display to change. Look closely at the video.
TYGNYBNT. Don't eat your pets. Speaking of that, in 1965 while temporarily stationed on Okinawa (at that time call sign prefix KR6) we were cautioned not to order burgers at the local A&W Root Beer stands as they might contain dog or cat meat. Yuk! Maybe Vance while in the USMC was stationed on Okinawa. Ohio Okinawa -- they both start with an O who knows.
73's
Pete N6QW