Re: Sending Multiple Scattered Logic Level Signals To a Processor

Thanks a lot Allen. This gives me some confidence in going ahead without
optoisolation for this project. Just realizing that unfortunately my
sensors output 5 volts so I would have to do some level shifting to use an
esp32. Maybe I'll try an Arduino to keep it simple as this is just a "one
of" project Jim

On Mon, Apr 28, 2025 at 11:09 AM Allen Mulvey <[email protected]> wrote:

> When I first started using ESP devices I optoisolated everything but it
> soon became apparent that that was overkill. I've had ESP devices
> directly attached to sensors, etc. in very hostile environments,
> greenhouses, for years with no trouble. Some of the display screens,
> especially the OLED displays, are no longer readable but the devices
> still work. Most send data by MQTT, some flip relays through a driver
> transistor.
>
> For communication I like MQTT because every device can both report and
> monitor.
>
> Allen Mulvey
>
> On 4/28/2025 10:38 AM, Jim Ruxton wrote:
> > I have a project where I want to send about 15 logic level sensor outputs
> > scattered around a room approx. 15' x 15 ' to a processor. The processor
> > could be an ESP32 , Pic or Arduino. I'm just wondering how folks would
> > handle this. Would you want to optically isolate at the sensor end? The
> > processor will be just outside that 15 x 15 foot space? I don't expect
> the
> > room to be particularly noisy electrically. Can I get away with just
> > connecting the logic level outputs to an input pin? The logic level
> signal
> > is very slow just an on or off trigger.  I imagine the longest wire
> length
> > would be about 25 feet. thoughts?
> >
> > Jim
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