Do I need more test equipment?

[chrisb741]

I recently started experimenting with digital circuits and microcontrollers, Arduino, rp2040, after decades of not doing any electronics, I have formal training from the 90s but didn't do anything electronics related since '99. I have a good HH multimeter and bench PSU. Have a decent oscilloscope I mainly use to decode serial signals. The oscilloscope has an AWG.
I have made some very basic driver boards but mainly use modules. I use one very simple wireless GFSK based communication board.
My projects have simple sensors, motors, servos, Steppers, display etc. I don't design any thing RF and have very little exposure to anything RF, what I use is entirely low power digital comms. I have played with RC equipment.
I have a few questions about more test equipment.
1. What benefit would I get using a bench multimeter. So far I only need to see roughly what the voltage is, eg 12 ish Volts or about 3v3. My handheld MM does that
2. Dedicated waveform generator, I've only ever used the pwm generator. What can I use the other features for?
3. SA, I've used one in the 90s a few times, what can I do with them that would help the kind of projects I play with. I can only see myself analysing the 2.4ghz spectrum.
4. RF signal generator and VNA. I have no idea about how to use these or what I could even use them for.
5. Any other test equipment I missed?

[robert.rozee]

i would say, from what you have described - digital, low voltage - that items you may find useful include:
1. several 'cheap' multimeters, DT-830 or similar and equipped with leads that have crocodile clips on the ends. these are invariably useful when experimenting on the bench.
2. if you don't already have it, a good soldering station.
3. a bench meter can be handy for logging readings, although you may be able to roll your own. i recently picked up a nice fluke 45 which is ideal, having a serial port on the back. certainly don't go crazy spending money.
4. additional small power supplies are also useful, even just 'power-bank' types.
5. a dedicated bench computer can be exceptionally useful, something like an elderly laptop running XP or Linux. also doubles as a 2-channel audio signal generator, serial terminal, and 5v PSU (via a USB port). cheap means expendable if something goes wrong!


cheers,
rob   :-)

[forrestc]

I've found over the years that once you have a power supply, decent DMM, and often an oscilloscope you often have enough test equipment to handle all of your typical hobby electronics - at least until you start specializing in some specific area.

The need for anything beyond that will become apparent as you explore electronics, and will be specific to the type of electronics you are working on

Let me give you a couple of examples relevant to what I do.

I do a lot of FET switching of DC power loads, including overcurrent sensing.   As such, I need to be able to draw a certain amount of current through my circuit and verify the current sensor is working, and that I can turn on and off loads without causing a failure or overheating.    I could do this with a big enough power resistor, but I find it easier to use a DC load, which allows me to connect to my circuit and draw a specified amount of current and vary that current as needed to test my device.   For me, this is essential gear.   For someone who doesn't do this type of work, this would be useless.

Likewise, I work on various products that receive precision time pulses from a GPS receiver and then provides that timing pulse to communication radios.   As such, I often need to be able to measure how much delay is being added by my products and also verify that the signal is consistent over hours or days.   I can do some of this with a good multichannel oscilloscope, but for long-term use it's much easier with a timestamping or universal counter such as the TAPR TICC or the HP 53132A.   If you're not doing precision timing, these would be useless to you.

I also, on occasion, have to work with some sort of communication protocol such as asynchronous serial, CAN, USB, and the like, and this is often enough that I've accumulated a few protocol analyzers for this.   For someone who rarely does this, often decoding on a scope is enough, so you don't need to spend money on those tools.

So, it really depends on what you're working on and the challenges you regularly run into.   If you were doing audio amplifiers or other audio processing you'd probably want some sort of audio analyzer to do THD and other purity measurements.   If you're building radio transmitters and receivers (as opposed to doing modules), you'd probably want a spectrum analyzer and a RF signal generator.   On the other hand if you were building antennas, you'd probably want that VNA.   And on and on. 

My suggestion would be to not worry about acquiring any additional gear until you find a shortcoming in what you have when working on the projects you want to work on. 

I will answer, however, one specific item on your list.   As far as a bench DMM goes, one of the big advantages is that it can be plugged in and is more mechanically stable than a handheld DMM.   This is beyond any other features, such as ability to do advanced or precision measurements.   So if you have a fixed workbench area, a bench DMM and other "bench" versions of your test equipment can be useful.    For example, I have a small ethernet switch, a small USB hub, a USB "charger brick" with multiple outputs, a power strip, and other similar objects all physically mounted in my bench area.    Since a bench PSU and a oscilloscope are both typically bench instruments, adding a bench DMM just because of the form factor makes some sense.   

Note that I have specifically ignored the other advantages of a bench DMM as they may or may not be relevant to you.  If you were doing precision measurements, then having a high count DMM makes some sense.  And so on.   But these are the same arguments as for the other instruments.

[DaJMasta]

Yes, you do, see TEA thread.



In a more serious take, don't buy it just to have it.  You've got a good set that will be broadly useful and pretty capable.  If you find yourself needing additional capability, then look into getting something for that.  The equipment out there isn't going anywhere, and if you eventually decide you need something expensive, in time a deal will come along should that be the only way you can get it.  While the equipment can be interesting, unless you think you're really going to use it for something, is the interest alone enough to invest in it?

[tautech]

I recently started experimenting with digital circuits and microcontrollers, Arduino, rp2040, after decades of not doing any electronics, I have formal training from the 90s but didn't do anything electronics related since '99. I have a good HH multimeter and bench PSU. Have a decent oscilloscope I mainly use to decode serial signals. The oscilloscope has an AWG.
I have made some very basic driver boards but mainly use modules. I use one very simple wireless GFSK based communication board.
My projects have simple sensors, motors, servos, Steppers, display etc. I don't design any thing RF and have very little exposure to anything RF, what I use is entirely low power digital comms. I have played with RC equipment.
I have a few questions about more test equipment.
1. What benefit would I get using a bench multimeter. So far I only need to see roughly what the voltage is, eg 12 ish Volts or about 3v3. My handheld MM does that
2. Dedicated waveform generator, I've only ever used the pwm generator. What can I use the other features for?
3. SA, I've used one in the 90s a few times, what can I do with them that would help the kind of projects I play with. I can only see myself analysing the 2.4ghz spectrum.
4. RF signal generator and VNA. I have no idea about how to use these or what I could even use them for.
5. Any other test equipment I missed?

RF that you have dabbled with some is a magical world and an instrument like the SVA1000X range will cover #3 and 4.
The TG output when the analyzer is set to zero span can double as a RF gen albeit with limited amplitude compared to a dedicated RF gen
The VNA capability can assist to perfect antenna designs to extend range and/or reduce transmitter power requirements.
Example here:
https://www.eevblog.com/forum/rf-microwave/antenna-project-log/

[Fungus]

1. What benefit would I get using a bench multimeter.

You can leave it on all day and not worry about batteries.

[chrisb741]

Thing is I don't know what I don't know. There might be a better way of testing / monitoring something I have no idea about. I've been out of the electronics game a long time.

Money isn't really a problem now, just don't like wasting it on stuff taking up space I'll get very little use out of when I can spend it on more things to experiment and build.

Having said that need to digest this info.
Cheap local PC to program uC at the bench would be good, instead of using my home office. Those small PCs in a small box should be fine for such simple work. Got network ports.
Bench DMM, mentioned a few times, now that I think about it, yes do occasionally need to monitor multiple things at once. Might as well get an bench one, don't need high digit count
I do have a few extra cheap PSU units.

SA/VNA, DC load, AWG, no need, yet. Most of the RF stuff I know nothing about.  My education lightly touched on that.

I do have a 3D printer, that's very useful.

Got a soldering station

Thanks for your suggestions

[Aldo22]

Money isn't really a problem now, just don't like wasting it on stuff taking up space I'll get very little use out of when I can spend it on more things to experiment and build.

What I would buy anyway because it's cheap and doesn't take up much space:

A component tester (like this or this).
A NanoVNA
A TinySA or TinySA Ultra

Even if you don't know what it's for yet, you'll find a purpose.

I use the NanoVNA e.g. to identify small, non-labeled SMD Inductors and capacitors.
I have no other tool to measure nano- and microhenry.
I tinker with self soldered low pass filters. The NanoVNA shows me if and how they work etc.

The TinySA can also be used in the Arduino field, e.g. to see if 433MHz RF modules work etc.
I can also use it to see if the car key door opener still works. 

Just simple examples.
There is much more to discover.

They are so cheap that it is not worth to do without them. 

[Berni]

Yep once you got the basics of PSU, DMM, Scope covered you are set. Anything more depends on your specific needs.

For Spectrum analyzers, network analyzers, synthesizers, RF power meters..etc you only need if you deal with RF stuff.

Just buy gear as needs arise. For example if you do a lot of digital you might want a logic analyzer. If you deal with high power electronics you might want some extra big boy PSUs or electronic loads. If you deal with high def audio you might want sensitive preamps and distortion analyzers etc..

There are various reasons why you might want a Bench DMM:
- Does not need batteries, so it can be left on all day to monitor something.(like a charging battery, or temperature of something..etc)
- Fits on a shelf, so it is always in the same spot ready to be used, does not take up bench space, can have other instruments stacked on top..etc
- Much higher performance. Since there is no limitation for power usage these DMMs can afford to have a more fancy precision electronics inside. They take readings faster, they have more digits, they have better precision references inside, they have HighZ mode etc..
- Better connectivity, so you can fully control the DMM over GPIB, RS232, USB, Ethernet..etc
- Better display, so you can see it clearly from all angles and in the dark.

[tggzzz]

Do I need more test equipment?

Answer 1: yes of course you do.  The denizens of this thread will be pleased to help you https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/

Answer 2: no, because you had to ask the question.

It is pleasing to demonstrate skill and imagination by being able to "do more with less" to find ways of working out what's happening. One old example from my schooldays is how to use a 2% meter to measure voltages to 0.1%, using only a meter rule, a meter of resistance wire, a NiFe cell and one well defined voltage, 1.018V. Another is that I implemented and tested my first computer (a 6800 with 128bytes(!) of RAM) with only a LEDs, switches, and an analogue multimeter.

Every piece of kit will have a learning curve, especially for the GUI and how to use it to get useful results. Spend your remaining life wisely.

It is worth while understanding what affordable kit is out there, so you can work out when you need it. Example: different scope probes for different problems such as measuring mains circuits safely.

Overall: you will know when you need more equipment, because you can't achieve your objectives with existing kit.

[RoGeorge]

1. What benefit would I get using a bench multimeter. So far I only need to see roughly what the voltage is, eg 12 ish Volts or about 3v3. My handheld MM does that
2. Dedicated waveform generator, I've only ever used the pwm generator. What can I use the other features for?
3. SA, I've used one in the 90s a few times, what can I do with them that would help the kind of projects I play with. I can only see myself analysing the 2.4ghz spectrum.
4. RF signal generator and VNA. I have no idea about how to use these or what I could even use them for.
5. Any other test equipment I missed?

1.  Unless you are interested in metrology, or in need of some very high accuracy and precision, you probably won't need one.  Another reason might be when you need to measure fast, for example on an industrial assembly line, where one would want to make automated measurement (for testing) at fast as possible, so to keep the production running.

For digital circuits and small modules you plan to build with, I can not come with any pertinent example where only a bench multimeter would be capable to do the measurement.  A DMM would be enough.

2.  A waveform generator with sinus/ramp or other waveform is nice to have particularly for analog projects.  For digital, not much.  However an AWG (Arbitrary Waveform Generator) might come in handy if you want to generate a certain train of pulses, or some other waveforms.  Same as above, nice to have, but not a must have.

3.  SA - Same, unless you have project where you tinker with RF, you won't need one.

4.  RF generator and VNA - for hams, tuning antennas, other analog and RF projects, sometimes also used for measuring small inductances/capacitances, find resonant frequency, etc.  No need for one when using with casual digital modules at home, unless you start developing your own 2.4GHz boards, with PCB antennas and such.

5.  Other instrument?
- DMM is a must have.
- Solder Station + hot air tool (not exactly test equipment, but you'll need one eventually)
- LA  (Logic Analyzer), rather rarely used - only if you need to log digital signals, or to capture longer communication than what would fit on the oscilloscope screen/memory, might be nice to have, not mandatory
- Computer, of course 


It is better to buy only when you need, not for "just in case", or else you will end up with empty pockets and shelves full of instruments never used. 

Of course, there is the reverse aspect, where one would find a use for whatever tool is at hand.

For example, I bought my AWG when I got interested in SDR (Software Defined Radio), because I was in need to experiment with 2 synchronous signals at the same time.  Of course, any sound card would have been enough for learning the principles, but I wanted a new toy.  By the time the AWG arrived, all my questions were already answered, so no need for an AWG, but I kept it on the bench.

Later, I've start using it for various other projects then the one I bought it for.  Sometimes I even used it as a voltage reference/power supply (for very small currents only) because it can also generate DC.  Then I've used the counter/frequency meter from it, and so on.  If you have a tool at hand, eventually you'll find all kind of ways to use that tool for, sometimes in ways the tool was not meant for.

To sum it up, the instruments to have would be (in this order):
- DMM
- Oscilloscope
- Solder Station
- Power Supply
- then (optional) AWG, LA, SA, VNA, etc.

Another aspect, the more instruments one has, the less projects. 
No idea what is the root cause, but it usually happens to everybody.

[nctnico]

I'd hold off any investment until you run into a problem your current test equipment can't solve. But do keep an eye out on equipment that makes life easier / allows to get better results quicker.

[armandine2]

2. Dedicated waveform generator, I've only ever used the pwm generator. What can I use the other features for?

if you can do it

[tridac]

Been collecting test gear for the lab for many years. Often buy broken and fix up, with Ebay and industrial auction, valuable resources. You can build up a working set over a yaer or few, buying in haste at times, but then get more selective, weeding oout stuff that is never or only rarely used. Even when you thunk you have everything, there's alwasys something to tempt for an upgrade, or better capability. It can become a lifetime's work, For basics, you need a dvm, and a good dual beam  scope at minimum, then perhaps pad out with a logc analyser and signal / pulse generators for ranges of interest. Suprising how much can be done with simple tools...

[Calambres]

Everyone's recommending a DMM which is wise but I'll go a step further: TWO DMMs

One for V
One for A

It is essential for me anyhow 

[Doctorandus_P]

5. Any other test equipment I missed?

Yes, go get yourself at least one of those EUR7 Logic Analyzers from Ali / Ebay / China, and use it with Sigrok / Pulseview. I also have an oscilloscope, but I use my logic analyzer more with debugging microcontroller projects. It is both a small gadget that fits easily next to a breadboard, and the PC interface with mouse works quite well in Sigrok. For an oscilloscope the the buttons and rotary encoders are an important part of the user experience, but for a LA, the mouse, keyboard and a PC monitor works quite nice. I also find a LA more convenient because you can work easily with "Dupont" wires on a breadboard instead of the unwieldy big oscilloscope probes.

But I also agree with the others, don't buy equipment too quickly. You will probably know it quite soon when you will need any of the more specialized things.

And you can also make simple yet useful things yourself. One of the simple things I made is an ULN2803 with 8 resistors and 8 LED's. It lets me keep track of a bunch of digital signals on a breadboard visually without loading the signals too much.

[chrisb741]

Cool, thanks all for the info.
The first processor I ever played with was something like to 8085, an 8-bit 40-pin micro-controller that had ROM chip you erase with UV light
Today I bought, a bunch of heat shrink pieces and a cheap mini PC.
Time to work on my project, sending commands from a web site to python script to rpi than wirelessly to an arduino controlled mecanum wheeled vehicle

[nctnico]

Everyone's recommending a DMM which is wise but I'll go a step further: TWO DMMs

One for V
One for A

It is essential for me anyhow 

A power supply with good internal metering is much nicer as it doesn't need extra bench space and doesn't need an external DMM. At some point I was contemplating buying more DMMs to measure power supply outputs but then it dawned to me getting a power supply with good internal metering made much more sense.

[RoGeorge]

sending commands from a web site to python script to rpi than wirelessly to an arduino controlled mecanum wheeled vehicle

 

[dmulligan]

5. Any other test equipment I missed?

Yes, go get yourself at least one of those EUR7 Logic Analyzers from Ali / Ebay / China, and use it with Sigrok / Pulseview. I also have an oscilloscope, but I use my logic analyzer more with debugging microcontroller projects.

I couldn't agree more.  These come in handy with Arduino and other digital projects.  You can't argue with the cost, and now you that have a mini PC on your desk anyhow it makes even more sense.

[slugrustle]

Have you had the need to measure higher bandwidth current waveforms with your scope?  A current clamp and/or rogowski coil might be useful, depending on how much of the power stuff you get into with motors.  Those things can get pricey though.

Similarly, differential voltage probes can come in handy for the scope if you need to measure voltages that aren't earth referenced.

Whoever said multiple multimeters had a good idea.  Personally, I am quite fond of bench multimeters, but electronics is both my job and my hobby, so I put a lot into it.  Might not be worth it for your use cases.

[armandine2]

... you (EUR7) could keep to a modest expenditure

or

dig a bit deeper - half the fun of the hobby is the exotic kit

[ledtester]

Just a couple of comments...

Have a decent oscilloscope I mainly use to decode serial signals.

I'd get a (cheap) sigrok compatible USB logic analyzer (cost around $10). They only do 24 Msps but they are much, much more convenient to use on long data streams. You can also get higher bandwidth versions if you need it.

Concerning VNAs -- I'd wait until you really find a need for one. They have evolved quite a bit recently so I would expect either significant improvements or cost reductions in the near future.

[chrisb741]

Can't see myself needing much speed for a logic analyser,  most monitoring would be real world based, pwm duty cycle and other digital in/outputs.
Can easily use a trigger with the 4 channel scope to record analog signals of needed.
Ordered a mini PC, amazon gave me a $50 discount coupon. Ordered a DMM, they had none in stock and gave me a free upgrade to the next model.
How much power do much projects use, not much, under 50W max.
That eez bb3 looks like an interesting project
TinySA wow cheap, they any good?

[Berni]

USB logic analyzers are mostly useful for looking at digital communication buses that have a lot going on. For looking at a PWM signal a scope is much more suitable.

This is because they usually can steam data to the PC or even use compression so you can record Giga or even Tera samples worth of data in a single capture. So it allows you to record for multiple seconds or even multiple minutes of traffic. So no need to trigger on the area of interest and keep rerunning your test, you can just record it all and then scroll trough it at your own pace. Looking trough this much data is much easier with a mouse as opposed to knobs on a scope. So for that reason i prefer it when looking at something like a SPI or I2C sensor or picking apart a UART firmware update protocol or something.

I never used the TinySA, but i do have two versions of the TinyVNA. Very nice little tool for measuring the impedance of things at high frequency, certainly the ultimate low cost tool for antenna tuning for example. Tho careful with stepping into RF as you quickly start collecting a lot of RF accessories (cables, adapters, terminators, attenuators...etc).