Design22

Group Assigment¶

Group Assigment Requriments

- Use the test equipment in your lab to observe the operation of a microcontroller circuit board (as a minimum, you should demonstrate the use of a multimeter and oscilloscope)
- Document your work on the group work page and reflect what you learned on your individual page

Testing Devices¶

Testing Devices

For the group assigment I have used the following devices for my testing:
- Multimeter: A multimeter, also known as a volt-ohm meter (VOM), is a versatile electronic testing tool used to measure electrical voltage, current, resistance, and continuity.
- Gw INSTEK Oscilloscope: GwINSTEK Oscilloscopes typically feature a high-resolution display, multiple input channels, and a range of measurement and analysis tools, such as waveform averaging, FFT analysis, and automated measurements.
-PicoScope PC Oscilloscope: PicoScope PC Oscilloscopes are designed with intuitive software interfaces that allow users to quickly and easily configure and run measurements. They also offer a range of advanced features, including signal decoding, spectrum analysis, and arbitrary waveform generation, as well as the ability to capture and analyze multiple channels of data simultaneously.

As part of our group assignment, we are required to test multiple devices to obtain various readings. To achieve this, I have opted to employ a multimeter to measure voltage and an oscilloscope to capture DC signals. For the purpose of our testing, I utilized the Adafruit Feather Sense nRF52480 to generate signals and provide voltage. The following code was used to generate the signal:

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

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

Multimeter Terminator TMM7201¶

To measure the voltage, I utilized the Terminator TMM7201 multimeter and configured it to measure up to 20V for reading.The output voltage listed in the datasheet for the Adafruit Feather Sense nRF52480 is likely listed as 3.3V because that is the nominal voltage that the device is designed to output. This nominal voltage is often used to simplify the description of a device’s output voltage and to make it easier for users to understand the device’s capabilities.

In reality, the output voltage of the device can vary slightly from the nominal voltage due to a number of factors, such as manufacturing tolerances, temperature, and load conditions. Additionally, the accuracy of the multimeter used to measure the voltage can also affect the measured value.

Therefore, a measured output voltage of 3.27V instead of the nominal 3.3V is within the expected range of variation and is unlikely to significantly affect the device’s performance.

Gw INSTEK Oscilloscope 1152A-U¶

To scope the signles, I utilized the Oscilloscope 1152A-U oscilloscope and configured it to scope to 500mv for reading. There are several possible reasons why there may be noise in the output signal scoped in the Gw INSTEK Oscilloscope 1152A-U from the Adafruit Feather Sense nRF52480.

Here are a few potential causes:

Grounding issues: Noise can be caused by grounding issues, where there is a difference in ground potential between the Feather Sense and the oscilloscope. This can create a ground loop, which can result in unwanted noise in the signal.
Interference: There may be interference from other electronic devices or equipment in the vicinity, such as motors or power supplies, which can introduce noise into the signal.
Signal quality: The signal being output by the Adafruit Feather Sense nRF52480 may not be of high enough quality, which can result in noise in the output signal. This could be due to issues with the signal source, such as poor shielding or inadequate filtering.
Oscilloscope settings: The oscilloscope settings may not be optimized for the particular signal being measured, which can result in noise. For example, the trigger level or timebase settings may not be set correctly.

To troubleshoot the issue, you can try the following steps:

Ensure that the Feather Sense and oscilloscope are properly grounded and there are no ground loops.
Move the Feather Sense and oscilloscope away from other electronic devices or equipment that may be causing interference.
Check the quality of the signal being output by the Feather Sense, and ensure that it is of high enough quality.
Adjust the oscilloscope settings to optimize them for the particular signal being measured.

PicoScope PC Oscilloscope¶

To scope the signles, I utilized the PicoScope PC Oscilloscope oscilloscope and configured it to scope to 5v for reading. To enable the display of signals on a PC, it is essential to download the PicoScope 7 software for this device.

There are several possible reasons why there may be less noise in the output signal reading on the PicoScope PC Oscilloscope compared to the Gw INSTEK Oscilloscope 1152A-U, even when both are connected to the same output signal from the Adafruit Feather Sense nRF52480.

Here are a few potential causes:

Input impedance: The input impedance of the PicoScope PC Oscilloscope may be higher than that of the Gw INSTEK Oscilloscope 1152A-U. A higher input impedance can result in less loading on the signal source, which can reduce noise.
Bandwidth: The bandwidth of the PicoScope PC Oscilloscope may be higher than that of the Gw INSTEK Oscilloscope 1152A-U. A higher bandwidth can allow for more accurate signal measurements, which can reduce noise.
Signal processing: The PicoScope PC Oscilloscope may have more advanced signal processing capabilities than the Gw INSTEK Oscilloscope 1152A-U, such as digital filtering or signal averaging. These capabilities can help to reduce noise in the output signal.
Grounding issues: The Gw INSTEK Oscilloscope 1152A-U may be experiencing grounding issues that are causing noise to be introduced into the output signal. This can be due to a difference in ground potential between the oscilloscope and the signal source, or a ground loop.

To further investigate the issue, it may be helpful to compare the specifications of both oscilloscopes, including their input impedance, bandwidth, and signal processing capabilities. Additionally, it may be useful to check the grounding of the Gw INSTEK Oscilloscope 1152A-U and ensure that there are no ground loops or other grounding issues present.