I don't know anything about electronics but am hoping to learn as I start playing with the Arduino. I'm not even sure if the Arduino will capture my attention for long (so I don't want to invest too much into these tools) but I do want to have the necessary tools so that I can give it a real go.
I don't need anything fancy, just something that will help me troubleshoot problems when I start using the Arduino. I'm currently reading Getting Start with Arduino 3rd ed but haven't gotten to the electronics part yet. I also don't have the Arduino yet, just preparing.
I use a free one from Harbor Freight. If you have one near you, check it out. They hand out coupons. Vet day sale starting the 10th as well. You can literally buy a $0.39 trinket and get a free multimeter.
I have fancier ones back at the parents' house on the other side of the country but have had no reason to bother having them shipped, the freebie one works great.
You can get them for around $3 with free shipping on Aliexpress or eBay. The electrical engineers will scream that the cheap DMMs will kill you if you connect them to high voltage but they work just fine for most any application the average Arduino user will need. I recommend spending a few cents more to get the one with the audible continuity indicator, which is indicated by the little speaker symbol next to that setting on the dial. I find that feature very useful.
Yep. Strangers on the internet will tell you to spend half of your income on a meter, the other half on a soldering station, and the other half on campaigning against the use of delay.
Yep. Strangers on the internet will tell you to spend half of your income on a meter, the other half on a soldering station, and the other half on campaigning against the use of delay.
Every bit of that is valid.
I still have the same soldering iron from 1978... It works and was that good. (weller) I did not buy the cheapest.
I still have the same Fluke multimeter from 1987... works perfectly... I have had 3 harbor freight meters die on me.
Delay() sucks... deal with it.
Amount spent on Meters and Soldering iron well worth it to have them a lifetime. You of course can keep buying them again as yours die young deaths or lack features needed to do good work.
A cheap meter is WAY better than no meter and you can always upgrade later if you feel the need.
I also built a little low-voltage voltage-tester with a probe, an alligator clip, a couple of LEDs (one for each polarity) and a resistor. (It's NOT a substitute for owning a meter, but there are times when it's more handy and it's super-cheap & easy to build.)
You can also build or buy a continuity tester, but personally I just use the beeper function on my meter.
A couple of minor issues I've seen on cheap meters:
Short non-removable, non-replaceable leads.
A non-replaceable current-fuse (over-current once and the current function is dead).
No low-AC voltage range.*
A non-standard battery.
I paid around $100 for my meter, and it doesn't read AC millivolts. If I ever decide to upgrade, that will be the reason.
Let me ask this question in a different way. If a multimeter will only be used for arduino related projects, should sensitivity be taken into account? I imagine the voltages and currents that are dealt with will be rather low, so perhaps something to look for in a multimeter is how low of a voltage or current in can measure.
Does that make any sense?
Is there particular functions that I should look for? I've put audible continuity test on the required features list already.
Continuity, typically voltages < 12V (and sometimes to confirm AC being present), measuring resistors!, sometimes AC frequency is very handy (ripple on DC voltage), as well as supporting a temperature probe.
Extech makes some nice meters with a temperature probe in the $40-45 range, we use two of them, mostly for the above. EX330 I think. Got the last one on sale at local electronics supplier - watch for Veterans Day sales for example.
It has worked well for my needs. I haven't found them to be unreliable unless you blow the fuse or whatever by abusing it but it's cheap enough you can afford to have a spare on hand just in case.
It's basically the same item that INTP and Hutkikz were talking about but the one I linked has free shipping and the audible continuity indicator feature.
The eBay sellers of this sort of thing like to shuffle their prices around. This one is $2.96 USD with free shipping anywhere right now. So if that changed you might be better off searching around a bit for a better price. This ships from Hong Kong so it might take some time to show up so if you're in a hurry to get it you might need to look for a Canadian seller and pay more.
This is the graphic that indicates it has the audible continuity indicator:
I agree with the low cost faction. You are just starting, you don't know how long you will do that, and expensive stuff also dies nowadays*.
You might also want a second meter to measure current and voltage at the same time.
What is mostly unimportant for now:
Accuracy. Mostly, you will want to know IF volatge is there, and if it is in a reasonable range. Ever DMM can do that. (Of course, if you spend some money, you want good accuracy, but if youz get bad accuracy for no money, it will still be ok). Exception: You want to build batery-powered devices for long run time. Then you need something that gives at least halfway meaningful results in the µA/mA range.
What I personally found useful but is not present in all meters:
Cap tester
Audio feedback for continuity (the very cheap ones often lack that)
What I also found super useful in the last few days: The JYE Tech DSO-138. You don't get high accuracy, you don't get high frequency, but you DO
See that your Chinese LED dimmer you are trying to read out gives some wacky multi-level signal instead of PWM
See that the load you put on your other Chinese LED Dimmer is too low so you don't get clean falling flanks in the PWM signal
See that your ultra-low-dropout regulator is or is not able to take the voltage spikes of the ESP
See that the leak resistor on your peak-hold circuit is well chosen
I won't claim it gives you an oscilloscope for 20$. But it gives you the ability to see all that stuff for 20$.
*Fun story: Recently, I got a Fluke test pen from amazon, turns out from a Chinese market place seller. It had a note in the manual that it is explicitly NOT CE conform. I believe this is genuine (a forger would bump a CE sticker on there) and it is a matter of market differentiation. While this is no indicator of quality, I find this highly scretchy.
