I was stumped for a while, and thought I would share this in case someone else is stumped.
https://www.adafruit.com/products/460
For the longest while, I thought you needed a special voltmeter to read a negative voltage. It never dawned on me that the simplest way to get this voltmeter to read negative was to reverse the direction of the leads meaning you put black to your negative supply and red to your ground.
Yeah maybe you don't have the minus telling you that it is negative but if you label it accordingly you'll know.
https://www.adafruit.com/products/460
For the longest while, I thought you needed a special voltmeter to read a negative voltage. It never dawned on me that the simplest way to get this voltmeter to read negative was to reverse the direction of the leads meaning you put black to your negative supply and red to your ground.
Yeah maybe you don't have the minus telling you that it is negative but if you label it accordingly you'll know.