Analog Input

[ranz]

Did some testing on my own. VEMS 300BAR MAP sensor shows at absolute pressure 1,654V, when I connect round to it, it shows 2,1xx. Now i soldered 10kOhm resistor to wire but still the reading is affected, 1,8xxV, tried with 40kOhm resistor... then it's almost stable, 1,681.
Now i'll try to get the reading right @ the gauge, more testing testing testing

EDIT: with 40kOhm resistor it's not possible to calibrate, the signal is too weak. But doesn't diode do the trick? I'll try that tomorrow.

EDIT1: No, the diode does not work, reference voltage is higher than MAP output, with diode it will show only values higher than 4V.
Now i visited one friend and he said that it's no problem to do little schematic and it should work... I'll keep you informed.

EDIT2: it works the schematic is very very simple, I'll post it later (friday i think).

[ranz]

With this schematic the MAP output is not affected and you can connect signal from OUTPUT directly to the gauge.
For VEMS 300BAR MAP my analog in gauge settings are:
Firmware version: 2009-03-03
Calibration: 64
Offset: 0
Analog in curve:
0
0
0
0
0
0
0
0
0
3
38
73
107
136
169
225
240
Now gauge shows pressure in kPa.

Button thereshold is 128 and button changes value when you hold it 1 second. If you just press it once, it does nothing, when you hold too long, it shows something like -FA, press again and it goes back.

[rob@vems.co.uk]

Awesome work there, thanks for posting it.

[ranz]

It should work also without capacitor, but we used it anyway.

[Too slow]

Hello,

has anyone tryied analog in to show (water) temp? How to connect the (wems webshop) ntc sensor to gauge? one wire to analog in (pin8) series with a resistor (size)k? and the second wire to?   

Tryied with connecting the second wire to ground. Changed the button threshold and then got it to work with 15k resistor, but the analog value isn't stable and the curve is narrow..