Picomite/PicoMiteVGA V5.07.05 release candidates


Author Message
Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 3331
Posted: 07:05pm 06 Dec 2022      

Dear PLuto,

Not sure about you, but I do not have a good feeling about the frequency measurement results (Setpin x,FIN).
The readout (also in lower frequencies) is not accurate. Like it is missing counts.
I will dive into it a bit deeper, but the combination with PWM and FIN counting inputs does not work as I thought. I wanted to see exact numbers.


Here are some results

PWM            FIN FREQ             SCOPE FREQ
20000          20000                20000
50000          50000                50000
80000          80020                80030
100000         99000/99950/99991    100000
200000         198000

Every time I run the program, PWM at 100kHz, the reading is different (more or less consistent), but different. I hope my text is clear. When I restart the program, the reading can be 99940 and stay around that value for minutes. Stop the program, restart, and the value can be 99000, and that value remains similar over minutes.

100000 99991
100000 99988
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99990
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991
100000 99988
100000 99991
100000 99991


Based on these measurements I can only conclude the frequency counter can be used up to 50kHz.

Volhout
Edited 2022-12-07 05:24 by Volhout