[Open_electroporator] culture shock ADC and DMA

[Nathan McCorkle]

On Wed, May 9, 2018 at 8:20 AM, John Griessen <john at cibolo.com> wrote:

> On 05/08/2018 03:37 AM, Nathan McCorkle wrote:
>
>>  docs report 210kHz with no dropped samples from 2 ADCs. -- So that seems
>> to be about the best we're going to do in a C loop reading the ADC in an
>> ungated situation (i.e. as fast as we can go, since faster than this they
>> were not getting the expected number of readings).
>>
>
> Sounds good for using micropython code without getting into C language
> except for some register writes
> and using DMA.
>

I made some progress finding out how to quickly perform the register writes
from C,
https://forum.micropython.org/viewtopic.php?f=3&t=4847&p=27917#p27912

So we're starting on our way to a control loop. I am thinking to avoid
using the HV side, I can inject a signal-generator into the ADC input, and
then I can watch the pulse width of the GPIO along with the mock-ADC-input
and see if there's some correlation (i.e. if I feed in a sine wave, and
program the code to adjust the pulse width, I'd expect as the sine wave
rises, the pulse widths would get shorter... as the sine wave lowers, the
pulse widths get wider). Then if I get a loop that seems to work from
low-side voltage perspective, maybe I use a different lower-voltage
power-supply for the high-side. I think the laptop power brick I've got is
19 or 20V... so maybe I can supply 10V or 12V instead, that way if my code
glitches and the HV side is pushed to the max... the max will be under the
damaged-limit for the hardware.

John, can you tell me what voltage I should feed into the high-side to be
under that limit in a max-pulse-power situation?
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