Absolutely right, the Nano is overloaded, and i2c writes to a display slow it down further.
However, sending CW is reasonably slow, even for a Nano clocked at 16mhz.
Lets assume we are shooting for good operation at 20 wpm.
The word "PARIS" including inter-character and inter-word spacing has the equivalent of 50 dot elements,
So 20wpm is 20*50/60 = 16.66 dots/sec, a rising or falling edge every 1/(2*16.66) = 30 milliseconds.
If you are updating a slow display while in the midst of sending CW, you are doing it wrong.
And if you want to catch the very first dot of a transmission on an overloaded processor,
it had best be keyed through a digital pin that generates a high priority interrupt.
I've used an i2c 16x2 LCD on my uBitx v3, but would not recommend using i2c on a larger display.
My stripped down code only does straight key mode as well, mostly because I wanted it as simple as possible.
Any keyer must be external.
A faster processor with more pins and more memory would make many things a lot easier.
Jerry, KE7ER
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On Sun, May 16, 2021 at 05:34 AM, Bill Cromwell wrote:
Hi,
I went back to using an external keyer just because of the clumsy operation of the built-in keyer in my V3. The uBitX then sees straight key operation regardless of what is outside the radio or what I am doing at my fingertips:)
The lil processor in the radio is overloaded to my way of thinking. It is 'almost' good enough'. The suggestion of using a serial display will slow down the display and there have already been complaints about that. I have some serial displays and I may try one to see if it is tolerable. Some CW ops have reported improvements by tweaking the resistor values for the analog keyer pin. A search of messages or the files section should turn up that approach. Use of a processor with more resources sounds like a better idea. It will cost a little more, of course. "Cost creep" is a real thing.
I have a much different approach to the entire enterprise and *if* I get it completed and *if* it works I will publish the results. My silly ideas are to rearrange the existing blocks with other existing blocks. CW operation should not be an afterthought. Much of the rig in my mind is borrowed from the uBitX design. Some of those blocks are inspired by 'other' radios. No, Kentucky, not vacuum tubes <sly grin>.
73,
Bill KU8H
bark less - wag more
