I recently made a bunch of tools to tune/troubleshoot vintage cars which are all based on using a 1mA, 50R analog meter. Some are powered by 3V/DC - others from 12V/DC.
Just so you know, I did purchase quite a few 1mA meters but none of them had the low internal resistance required.
I purchased my first Arduino (Nano/Uno) a month ago, which makes me a newbie, and I am hoping it is possible to substitute the analog meter with ex. an Arduino/LCD.
One problem, I realize, is the fact that some circuits rely on the dynamics of the analog meter to show an "average" value which eliminates the easy solution of just bying a 1mA digital display.
Has anyone tried to make such an "analog" Arduino mA meter substitute? Is this at all possible? If so, difficult? I would really appreciate comments, links, examples - anything really?
/Dan
You could make many analogue readings and use the Arduino to average them.
My concern is that the meter may be in series with the battery, via component then ground. This makes it very difficult to get a common gnd reference. The supply voltage is also a concern.
weedpharma:
My concern is that the meter may be in series with the battery, via component then ground. This makes it very difficult to get a common gnd reference. The supply voltage is also a concern.
If you exclude the Uno (Atmega 328) most other Arduinos (or more exactly their Atmel MCUs) have the ability to measure the differential voltage between two Analog pins which would get around the common GND problem. They also include amplifiers for small voltage differences.
