OBD II Voltmeter


Idea: Devise a simple plug in meter that will work on any OBDII equipped vehicles.

While doing research I found that standard OBDII pinout will give you battery voltage on Pin 16 and a chassis ground on Pin 4. I started with a WM3476-ND housing and WM3455CT-ND male pins that would connect to the housing in my car.

For a voltmeter I selected the 1597-1236-ND from Seeed Technology. This meter will read voltages from 2.6-30VDC and is in a small 30/11.7mm screen size.
To ensure there was no issues cause by my circuit I also added an inline fuse F2308-ND.
I then took measurements of my different components and using free online software from OnShape I was able to create a housing for the voltmeter project. This housing was then printed on a Prusa 3D printer. Using the scheme it app from Digi-Key Corporation I was able to diagram the simple circuit.
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The initial unit was assembled and it was requested that I add an on/off switch so that the unit could be left in a vehicle and no voltage would be drawn. With a slight change to the schematic I added switch CH865-ND.

I then also created a new housing to accommodate the switch.
The housing was then printed and assembled. The working prototype is now functional.