Back To The CrowPanel Handheld Computer

[granz]

Well, in my first response (#1,) I showed the program, and it does close the data file, just before printing the date and time on the screen. So, I'm not sure what is going on there.

I just plugged it in, and here is the newly rewritten program:

Code Select Expand

Date$ = "01-01-2000"
Time$ = "00:00:00"

Do
  Open "b:test-time.dat" For append As #1
  Print #1, Date$, Time$
  Close #1
  Pause 300000 ' Delay for five minutes
Loop
This is basically the same as the above program - missing the display onto the screen.

Since, I had let the battery die, I will leave it plugged in until tomorrow to fully charge the battery. Then I will unplug it and immediately start the program. Hopefully, this will give us something with which to work on finding the troubles.

[Chris Savage]

Okay, so I guess I am wondering...did you see the time / date stuff being printed more than three times before it died before? I guess what I am wondering is, was the program actually running two or three hours later?

[granz]

Oh, it wasn't running that program. I just let the battery die, so that I could store it more safely. I'll get the experiment started tomorrow.

[granz]

Okay, I let the program run for a while and then broke it. It showed six entries in the data file.

So, I added a bit of niceness to give a count of how long the thing has been running:

Code Select Expand

> list
Date$ = "31-12-1999"
Time$ = "00:00:00"

cnt = 0 ' Number of minutes program has been running

Do
  Open "b:test-time.dat" For append As #1
  Print #1, Date$, Time$
  Print #1, "Running for "cnt" minutes."
  Print #1, "----------------------------------------"
  Close #1
  cnt = cnt + 5
  Pause 300000  ' Delay for five minutes
Loop
>
(If is ain't broken, keep playing with it until it is. )

I'll let it run for a bit to make sure that it works, then I will run it, and unplug the power. We shall see how long the battery lasts - without any power-saving efforts, like shutting off the screen.

[Chris Savage]

I'm guessing that there's no way, programmatically, to determine when it is running on battery versus mains?

[granz]

I'm guessing that there's no way, programmatically, to determine when it is running on battery versus mains?

I was going to say, no. But then I remembered that the Pico, itself, can read the incoming voltage. It took a while, but looking at the schematic (https://www.elecrow.com/download/product/DIS01135P/CrowPanel_Pico_Display-3.5_V1.0-SCH.pdf,) there is VBAT going to pin GP29 on the RP2040. That is the pin on the Pico that let's the chip read the incoming voltage.

When the experiments end, I will test out that voltage reading, and see if a program can tell if the power is applied, or it is running on battery.

[Chris Savage]

When the experiments end, I will test out that voltage reading, and see if a program can tell if the power is applied, or it is running on battery.

I was also thinking about having the program suspend when the battery gets below a certain point. I've done something similar on some Z80 systems I built back in the 90s.