B. Kainka

The Arduino-Inside Measurement Lab        

Elektor 2024      

https://www.elektor.com/products/the-arduino-inside-measurement-lab

A well-equipped electronics lab is full of power supplies, measuring devices, test equipment and signal generators. In addition, there are tools, components and the many assemblies and projects that you are currently working on. It can get crowded in the lab. Wouldn't it be better to have one compact device for almost all tasks? All in one, small and versatile, and also inexpensive and easy to procure.

After several attempts with other systems the choice fell on the Arduino Nano. On this basis, a PC interface as versatile as possible for measure-ment and control is to be developed. It simply hangs on a USB cable and, depending on the software, forms the measuring head of a digital voltmeter or PC oscilloscope, a signal generator, an adjustable voltage source, a frequency counter, an ohmmeter a capacitance meter, a charac-teristic curve recorder and much more.

The circuits and methods collected here are not only relevant for exactly these tasks in the electronics laboratory, but many details can also be used in completely different contexts. Often one encounters complex tasks in the field of measurement technology during development work with microcontrollers. In many cases, the methods from this book can then be used. You have a starting point and can develop the software in the desired direction.

Stay creative!

Burkhard Kainka

Software download: ArduinoMSR.zip

More information: www.elektronik-labor.de/AVR/ArduinoMSR.html



 CONTENTS

1 Preparations    1
1.1 Choice of controller    1
1.2 The Arduino Nano    3
1.3 Voltage supply    5

2 Preliminary tests    8
2.1 Port outputs    8
2.2 Analog inputs and outputs    12
2.3 The serial plotter    15
2.4 PWM signal generator    18
2.5 A sawtooth generator    20
2.6 Direct digital synthesis    23

3 GCC programming    27
3.1 Fast port outputs    27
3.2 PWM output    28
3.3 Timer interrupt    32
3.4 Fast sine wave generator    34
3.5 AD buffering    41

4 The MSR Laboratory    49
4.1 Dual-channel DDS generator    50
4.2 Binary serial transmission    52
4.3 Frequency setting    55
4.4 Deflection times and dual-channel operation    59
4.5 Triggering    64
4.6 DC voltage output    66

5 Additional inputs and outputs    69
5.1 Phase adjustment of the DDS    70
5.2 Signal generator up to 8 MHz    71
5.3 Frequency measurement    75
5.4 Additional analog inputs    80
5.5 Capacitance measurement from 1 pF    82
5.6 Resistance measurement up to 1 MΩ    85
5.7 Resistance measurement from 1Ω    88

6 Measurements and experiments    90
6.1 Subsampling    90
6.2 Investigation at higher frequencies    93
6.3 Measurement on a synchronous signal    95
6.4 Frequency response of a low-pass filter    97
6.5 An LC low pass    101
6.6 LC resonance    104
6.7 Transistor test circuit    107

7 Firmware extensions    112
7.1 Alternative DDS functions    112
7.2 Reduced amplitude    113
7.3 Triangle and sawtooth    114
7.4 XY representation    117
7.5 Frequency sweep    121
7.6 Ramp function    124
7.7 Measurement of characteristic curves    128

8 Application examples    132
8.1 The emitter follower    132
8.2 Emitter follower as impedance converter    133
8.3 Sallen key filter    135
8.4 Beat generator    137
8.5 Operational amplifier    139
8.6 Voltage doubling    142
8.7 All-pass filter    144
8.8 Bandpass filter    147

Appendix    150
List of components used    150

FAQ

It is unclear to me how the various components are to be combined: I can start: Terminal.exe, MSR.exe, but it is unclear to me how the various parts work together, the DDS1 and 2 etc

In the beginning I only use the Arduino software for programming DDS1, DDS2 and so on and for the Serial Monitor and the Serial Potter.
Later, e.g. page 38, I use Terminal.exe instead of the Serial Monitor in order so to see the bytes sent. In this case the Serial Monitor must be inactive to leave the COM free.
Chapter 5 shows the step by step development of the firmware and the VB6program MSR.exe. The end result is MSR2.exe.
If you want to use the final software MSR2.exe for all the experiments in chapter 6 to 8 you must flash NanoMSR2.ino into the Nano. Also you must edit MSR2.ini to write the COM number like COM2 or whatever your Arduino uses. Default is COM2.
 


See also https://www.elektronik-labor.de/AVR/ArduinoMSR.html

When you start MSR2.exe and see an error message “COM error”, one of the following things may have occurred: