Patientzero
Patientzero Dork
7/5/23 11:04 a.m.

I messed up and bought a pressure sensor for my nitrous bottle.  What I should have done is bought a whole gauge with sensor.  I'm feeding the 0-5v signal from the sensor into my Holley HP to control my bottle heater.  The problem is I can't view my bottle pressure from the drivers seat without having a laptop hooked up.  I would like a simple 4 digit display that I could mount in the dash and program(0.5v = 0psi, 4.5v = 1500psi)  Is there anything out there?  I bought a Raspberry Pi Pico and display with plans of trying to make something but my Python programming skills are limited as well as time.  Anybody have another idea?

Tutorial – Arduino and Four Digit Seven Segment Display Module |  tronixstuff.com

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/5/23 11:36 a.m.

Load micropython into that Pico and it's a fairly straightforward bit of programming - read an analog voltage input, turn it into a number, display. It's fairly easy to find code examples: reading an analog voltage and controlling a display. Keep in mind you will need to drop your 0-5v signal down to 0-3.3, which is just a matter of a couple of resistors.

If you don't have the time for that, just get a digital voltmeter and learn to think in volts instead of psi.

https://www.adafruit.com/product/575

stafford1500
stafford1500 GRM+ Memberand Dork
7/5/23 11:39 a.m.
Keith Tanner said:

Load CircuitPython into that Pico and it's a fairly straightforward bit of programming. If you don't have the time for that, just get a digital voltmeter and learn to think in volts instead of psi.

https://www.adafruit.com/product/575

or an analog 0 to 6 volt gauge and relabel it...

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/5/23 11:48 a.m.

In reply to stafford1500 :

Well, the request was for digital :) But analog would be a lot easier to quickly check. I don't know what the in-car environment is like, if precision is more important than a trend.

Patientzero
Patientzero Dork
7/5/23 11:53 a.m.

In reply to Keith Tanner :

I think it is MicroPython.  Will that work?  I feel like programming the input will be pretty straightforward but I don't have a clue what to do with the display.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/5/23 11:57 a.m.

I edited my comment to make it a little more generic. Micropython will work fine, here's your display example: https://www.tomshardware.com/how-to/raspberry-pi-pico-7-segment-display

Patientzero
Patientzero Dork
7/5/23 12:01 p.m.

Thanks Keith.  I'll try to spend some time on this and get it figured out.  Then I need to reprint my dash so there is somewhere to mount the display.  Ideally it will be mounted right in the middle above the buttons.

Patientzero
Patientzero Dork
7/5/23 12:02 p.m.

I just reread your edited comment.  Doesn't the Pico have a 5v input?

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/5/23 12:09 p.m.

In reply to Patientzero :

5v for power, but signal inputs cannot exceed 3.3v.

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