CurrentDongle attachment for the Analog Discovery 2

I actually use this simple board all the time, so decided to share it with the world.

It was made for these reasons:

• Simplifying current consumption measurement process, using AD2 bulit-in programmable voltage source, and dual INA186 amplifiers (for extended dynamic range)
• Breaking out BNC connectors, because, for some reason, such breakout board from Analog costs an ARM and a leg.
• Just breakout board for hacking stuff together

There's an simple bulit-in comparator circuit that blinks a LED when the channel range is reached. The high-accuracy channel usually also blinks when the DUT performs some action, which is also an useful feedback I guess.

In scripts folder, there's an example digilent waveforms script that I use for current measurement. Some things to note:

• programmable voltage sources on AD2 are noisy as hell when the current is under a couple of milliamps - hence the resistor in this area.
• the voltage offset errors from INA186s can be easilly callibrated out, using the provided script.

What this device is NOT:

• Crosstalk-free oscilloscope adapter
• Super accurate, self calibrating current probe
• Lab-ready device

Stuff to improve:

• The LEDs will not work when system is powered by 1.8V - but it's not fixable easily.

Some pics:

PCB connected to the Analog Discovery 2

PCB render

PCB IRL