Schematics / Diagrams for Components (opto-coupler) #1

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sickprodigy · 2024-05-04T11:58:24-04:00

sickprodigy commented

2024-05-04 11:58:24 -04:00

need to come up with some list of schematics / diagrams for all the components I have.

Can't remember how the opto-coupler functions exactly.

So I i got ground and power. Powering it using vsys currently, trying to figure out what kind of power is needed on vcc, currently have 0.98vdc.

That isn't quite clicking over the NO on the opto-coupler. NC has continuity

need to come up with some list of schematics / diagrams for all the components I have. Can't remember how the opto-coupler functions exactly. So I i got ground and power. Powering it using vsys currently, trying to figure out what kind of power is needed on vcc, currently have 0.98vdc. That isn't quite clicking over the NO on the opto-coupler. NC has continuity

sickprodigy commented

2024-05-04 12:00:54 -04:00

This could help
Doesn't explain what the module needs on the board to flip the NC/NO.

https://docs.micropython.org/en/latest/library/machine.Pin.html

but explains how to control the micropython function .low() or .toggle() I was working with before.

This could help Doesn't explain what the module needs on the board to flip the NC/NO. https://docs.micropython.org/en/latest/library/machine.Pin.html but explains how to control the micropython function .low() or .toggle() I was working with before.

sickprodigy commented

2024-05-04 12:40:35 -04:00

Alright 3v3 powers this module and 5v. How can I get 3v at 1 of the pins though for output?

4.3. Using the ADC
The RP2040 ADC does not have an on-board reference and therefore uses its own power supply as a reference. On Pico
the ADC_AVDD pin (the ADC supply) is generated from the SMPS 3.3V by using an R-C filter (201Ω into 2.2μF). This is a
simple solution but does have the following drawbacks:

We are relying on the 3.3V SMPS output accuracy which isn’t great
We can only do so much filtering and therefore ADC_AVDD will be somewhat noisy
The ADC draws current (about 150μA if the temperature sense diode is disabled, but it varies from chip to chip)
and therefore there will be an inherent offset of about 150μA*200 = ~30mV. There is a small difference in current
draw when the ADC is sampling (about +20μA) so that offset will also vary with sampling as well as operating
temperature.

https://datasheets.raspberrypi.com/pico/pico-datasheet.pdf#page=19&zoom=auto,-110,347

Sounds like any pins that are ADC can possibly put out a bit higher voltage? Can't quite figure it out.

Alright 3v3 powers this module and 5v. How can I get 3v at 1 of the pins though for output? 4.3. Using the ADC The RP2040 ADC does not have an on-board reference and therefore uses its own power supply as a reference. On Pico the ADC_AVDD pin (the ADC supply) is generated from the SMPS 3.3V by using an R-C filter (201Ω into 2.2μF). This is a simple solution but does have the following drawbacks: 1. We are relying on the 3.3V SMPS output accuracy which isn’t great 2. We can only do so much filtering and therefore ADC_AVDD will be somewhat noisy 3. The ADC draws current (about 150μA if the temperature sense diode is disabled, but it varies from chip to chip) and therefore there will be an inherent offset of about 150μA*200 = ~30mV. There is a small difference in current draw when the ADC is sampling (about +20μA) so that offset will also vary with sampling as well as operating temperature. https://datasheets.raspberrypi.com/pico/pico-datasheet.pdf#page=19&zoom=auto,-110,347 Sounds like any pins that are ADC can possibly put out a bit higher voltage? Can't quite figure it out.

sickprodigy closed this issue

2024-05-04 12:40:35 -04:00

sickprodigy reopened this issue

2024-05-04 12:40:41 -04:00

sickprodigy commented

2024-05-04 13:49:20 -04:00

I think the new bet is using a transistor powering a small voltage and then transistorizing to meet the full 3v spec