Electronics Design¶

abstract “What We Had to Do”¶

Okay, so for this group assignment, we needed to:
- Mess around with some test equipment in the lab to see how a microcontroller board works (at least use a multimeter and oscilloscope).
- Write up what we did on the group page and then think about what we learned on our own individual pages.

Testing Devices - The Tools of the Trade!¶

note “What I Used”¶

For this assignment, I grabbed these tools:

- **Multimeter:**  A multimeter (or VOM) is like your trusty sidekick for measuring volts, amps, ohms, and making sure circuits are connected properly.  Super handy!
- **Gw INSTEK Oscilloscope:**  These are cool 'cause they have a nice screen, let you plug in multiple signals, and have tools to analyze those signals (like averaging out the noise or doing fancy FFT stuff).
- **PicoScope PC Oscilloscope:**  These are neat 'cause they hook up to your computer! The software's pretty easy to use, and you can do things like decode signals, check out the spectrum, and even generate your own waveforms. Plus, you can watch multiple signals at the same time.

So, we needed to get some readings, right? I used the multimeter for voltage and the oscilloscope to peek at some DC signals. I used the [Adafruit Feather Sense nRF52480] to make the signals and voltage. Here's the code I whipped up:

```cpp
void setup() { pinMode(13, OUTPUT); pinMode(12, OUTPUT); }

void loop() { digitalWrite(12, HIGH); digitalWrite(13, HIGH); delayMicroseconds(100); // About 10% duty cycle @ 1KHz digitalWrite(13, LOW); delayMicroseconds(1000 - 100); } ```

Multimeter - Let’s Check Some Voltage!¶

Example “Measuring Voltage with the Multimeter”¶

To measure the voltage, I used this multimeter, the [Terminator TMM7201]. I set it to measure up to 20V. Now, the Adafruit Feather Sense nRF52480's datasheet *probably* says 3.3V, 'cause that's what it's *supposed* to put out. It's a nice, easy number to remember.

But, the real voltage can wiggle around a bit because of how it's made, the temperature, and what you've got plugged into it. Plus, multimeters aren't perfect either!

So, seeing 3.27V instead of 3.3V? Totally normal. No worries!

Multimeter Reading

Gw INSTEK Oscilloscope - Peeking at Signals!¶

Tip “Analyzing Signals with the Gw INSTEK Oscilloscope”¶

To check out the signals, I used the [Oscilloscope 1152A-U] and set it to 500mV. Now, there could be a few reasons why the signal from the Adafruit Feather Sense is a little noisy:

**Why the Noise? Here's What Could Be Up:**
- Grounding issues: If the Feather Sense and the oscilloscope aren't grounded the same way, it can make a loop that adds noise. Think of it like a hum in your guitar amp.
- Interference: Other stuff nearby (like motors or power supplies) can mess with the signal. Like when your phone rings and your speakers buzz.
- Signal quality: The signal from the Feather Sense itself might not be super clean. Maybe it needs better shielding or filtering.
- Oscilloscope settings: The oscilloscope might not be set *just* right. Like the trigger or timebase isn't dialed in.

**Okay, How Do We Fix It?**
- Make sure everything's grounded properly. No ground loops allowed!
- Move the Feather Sense and oscilloscope away from other electronics that might be causing trouble.
- Double-check the signal coming from the Feather Sense. Is it clean?
- Play around with the oscilloscope settings. Get them dialed in.

Multimeter Reading

PicoScope - More Signal Peeking!¶

Info “Analyzing Signals with the PicoScope PC Oscilloscope”¶

For scoping signals, I utilized the [PicoScope PC Oscilloscope]. To get it working on the computer, you gotta download the [PicoScope 7] software.

The PicoScope *might* show less noise than the Gw INSTEK Oscilloscope, even if they're looking at the same signal. Here's why:

**Why Less Noise on the PicoScope?**
- Input impedance: The PicoScope might have a higher input impedance. That means it doesn't "load down" the signal as much, which can reduce noise.
- Bandwidth: It might have a wider bandwidth, letting it measure the signal more accurately.
- Signal processing: The PicoScope might have fancier signal processing tricks (like digital filtering) to clean up the signal.
- Grounding issues: Maybe the Gw INSTEK Oscilloscope has some grounding problems that are adding noise.

Multimeter Reading

To really figure it out, you could compare the specs of both oscilloscopes (input impedance, bandwidth, etc.). Also, double-check the grounding on that Gw INSTEK Oscilloscope!