Megasquirt Support Forum (MSEXTRA)

In the hardware manual for MS3x section 3.3.3, js4 and js5 are listed as spare 0-5v analog inputs. The footnote below the chart says they are raw pins and need conditioners. The chart leads me to think all that is needed is a jumper to a spr3 and spr4. The footnote leads me think that it needs some work besides just the jumper. The hardware manual has images of projects in the proto area but I don't see any of them for an extra ADC. Do I need to do work in the proto area or just the jumper? If I need a conditioner circuit in the Proto area can you help me with which parts I need and a diagram?

OK, I think I found what I need in the ms3 v3.0 manuals. They have more info than the manual that includes 3x. A simple cap and resistor on each is needed.

3.4.9 Spare Analogue (ADC) inputs
The JS4, JS5 connections on the MS3 card can be used as 0-5V analogue inputs. The Generic Sensors system
should be used to translate the raw ADC value into useful temperature or pressure numbers.
Parts required. One 1k 1/8W (or 1/4W) resistor, one 0.22uF 10V ceramic capacitor.
Solder into proto area.Run jumper wire to JS4 or JS5 (your choice.) Run jumper wire to SPR3 or SPR4 (your
choice)

Or copy the circuit for TPS input. That has one additional cap, maybe a bit better noise rejection.

Thanks billr, add this cap on the other side of the resistor. Capacitor 0.001µF 100V 10% CER RADIAL - X7R

The more I think about it the more I think I just want an I/O extender.

brianj5600 wrote:OK, I think I found what I need in the ms3 v3.0 manuals. They have more info than the manual that includes 3x. A simple cap and resistor on each is needed.

3.4.9 Spare Analogue (ADC) inputs
The JS4, JS5 connections on the MS3 card can be used as 0-5V analogue inputs. The Generic Sensors system
should be used to translate the raw ADC value into useful temperature or pressure numbers.
Parts required. One 1k 1/8W (or 1/4W) resistor, one 0.22uF 10V ceramic capacitor.
Solder into proto area.Run jumper wire to JS4 or JS5 (your choice.) Run jumper wire to SPR3 or SPR4 (your
choice)

Would someone have a Digikey part number for this capacitor? I ordered something that fit the spec, but it doesn't have any legs, not sure how I'm supposed to solder it.

-Dave

Sounds like you've bought a surface mount component instead of a radial through-hole one. You should be able to solder it directly to the pads in the proto area.

James