Using ADC on CircuitPython

In this post, we’re diving into how to control an ADC using a variable resistor and a potentiometer.
We’ll also introduce a module and an expansion board, which are essential components for this setup.
The goal here is to show you how these parts work together to effectively control the ADC.
So, stick around to see how it all fits!.

Alright, let’s get started with connecting the module to your expansion board! First off, make sure that the USB port on the expansion board is at the top—this is super important for proper alignment.
Next, go ahead and connect the module by aligning its top part and securing it in place.
This setup will let you control everything via the A55 pin, which you can check from the back of the configuration.
After you’ve inserted the module, remember to reconnect it to your PC to keep things moving.
Finally, don’t forget to reopen that main file you used before to continue setting everything up.
Easy peasy!.

Alright, let’s break down what’s happening with the ADC code! The code is set up to check the ADC values from the A0 pin on the board, and it spits out the result every 0.1 seconds.
Since we’re dealing with a 16-bit ADC, its values run from 0 to 65535.
When it reads a voltage of 3.3V, it hits the max value of 65535 (even though it can technically register to 65536).
If you input around 1.1V, the ADC gives you a reading of about 33,000—that’s roughly half of the highest value.
And, of course, if there’s no input voltage at all, the ADC reports a value of 0.
This all shows how the code helps translate voltage into those ADC numbers..

Setting up a variable resistor with your kit is pretty straightforward.
You’ll want to connect it and keep an eye on the serial monitor to see what the ADC output looks like.
When you twist that resistor counterclockwise, you’re actually reducing resistance, which ramps up the current flow and bumps up your ADC values.
If you go all the way left, you’ll hit nearly 65 on the scale, which translates to about 3 V—a solid indication of maximum potential difference.
On the flip side, turning it clockwise increases resistance and decreases the current flow and ADC values, showing you the opposite effect.
All in all, this little trick really showcases how you can control the ADC with a variable resistor and makes those real-time adjustments super easy to manage..

In our last session, we had a chance to connect CircuitPython with the BLE module and the expansion board.
This setup allowed us to read the value of a variable resistor using ADC, which was pretty cool! Looking ahead, we’re set to tackle some exciting new topics in our next session, diving into fresh aspects that we haven’t explored yet..