Oscilloscope teaching tools - Page 1
Forum section: electronics / beginners

author: gfmucci
author_rank: Regular Contributor
timestamp: June 10, 2020, 09:22:46 pm
content: What is the best way to hook up my tablet to my oscilloscope to generate various waveforms from my tablet's signal generation app? Do I need to be concerned about grounding issues from the scope if the tablet is using a wall wart (no third pin) and would therefore (hopefully) be floating?Are there any kinds of cheap signal generator boards or kits that are specifically designed for teaching/learning and exercising the functions of an oscilloscope?Perhaps there is an Arduino-based methods that serves this purpose?Yes, there is. I Googled "Arduino-based oscilloscope training" and there are lots of options.

author: ledtester
author_rank: Super Contributor
timestamp: June 12, 2020, 08:05:47 am
content: Can you run your tablet on battery power (either its internal battery or an external battery pack)?

author: tggzzz
author_rank: Super Contributor
timestamp: June 12, 2020, 08:30:25 am
content: It depends on the details, of course.Normally "floating a scope" is regarded as a lethal trick. FFI seehttps://www.eevblog.com/forum/projects/isolation-transformer-for-scope/msg2259465/#msg2259465If your scope and tablet are floated, then their case will be at whatever voltage the probe shield is connected to. So will some of the internal connections; consider all the fault paths if you connect the shield to a mains voltage. Some scopes are specificallydesignedfor that to happen and are therefore safe within the stated limits. I strongly doubt that applies to your scope/tablet.Wall wart power supplies can be very variable in quality, from the good to the dangerous. The "isolation" can be merely sufficient to not kill you, but can still harm circuits.Even if none of that is dangerous, the capacitance between the scope probe's shield (and whatever it is connected to) and earth can be sufficient to damage some circuits.

author: RoGeorge
author_rank: Super Contributor
timestamp: June 12, 2020, 10:06:10 am
content: All oscilloscopes are supposed to have a square wave output for the probe calibration. That will be the cheapest way to get a signal. Read the oscilloscope's user manual to find out where on your oscilloscope is the signal output for probe calibration.The other even easier method is to just touch the tip of the probe with your finger.If you don't have an app for the tablet, there are youtube videos with various type of audio test signals. Constant sinus, increasing frequency, bass, square/sinus triangle, etc.If you don't have net for the tablet, download audio test signals then with other device, transfer the audio files to the tablet, and play the audio with the tablet.Tablet's wall adapters are suppose to be isolated, but just in case your is defective, don't listen to your headphones while the tablet is powered by a wall adapter, or taking a shower, or some other stupid things, and it'll all be fine.On the other hand, you probably get your oscilloscope to use it on some nice and cool projects, so just build what you have in mind and start using the scope. Have fun with it!What oscilloscope do you have?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 12, 2020, 10:31:23 am
content: I'm also curious what sort of scope / tablet / software combination you want to use.Almost any "real" scope nowaday's has Ethernet, so if you plug your scope in a router you should be able to reach it via WiFi.Then there are also the Tablet sized scopes from MicSig.For low frequency test signals you can use an audio output of your PC or phone. If you want to play "save", add a powered USB hub and some cheap USB sound output dongle. If you want to use your PC in your electronics corner, then make sure it's properly earthed, or else it will have half the mains voltage on all external metal and GND pins of connectors. This can be uncomfortable to the touch (but not really dangerous, as it's just leakage from pretty small filtering caps) but it's probably plenty to damage circuitry on you breadboard.Some time ago I bought the JDS6600 DDS Signal generator. It's not the best, especially the ladder DAC has some non-linearities, but for the price it's an excellent piece of equipment. I bought the cheapest "low frequency" version, as I thought that 10MHz was plenty for me.Davey Jones has some "oscilloscope test boards" which he has shown in some of his video's. One of his Keysight scopes also has a signal generator with some "demo" mode.Then there is stuff such as the "Digilent Analog Discovery" which seems to be highly praised, but above my budget. And some weird ducks, such as "Expeyes"https://expeyes.in/It's purposefully designed as a low entry educational gadged, but it may be enough especially for introductory courses in electronics.Or just build some simple circuits on a breadboard. Start with some oscillators such as with an NE555, the classic 2 transistor oscillator and other stuff on that level.If the oscillator is slow enough you can verify it works with a LED, and then poke deeper with your oscilloscope.

author: gfmucci
author_rank: Regular Contributor
timestamp: June 12, 2020, 10:19:40 pm
content: The scope that is #1 on my list right now (I don't have it yet) is the Instek 1054b. The tablet I would use most often is a Nvidia Shield, about 3 years old.Here are some of the apps I would use:https://play.google.com/store/apps/details?id=com.luxdelux.frequencygeneratorhttp://www.keuwl.com/FunctionGenerator/Here is the little beginner scope learning board and manual that fits my initial needs:https://www.amazon.com/dp/B06WP7W5N9/?coliid=IW9AQNUSZ3HJF&colid=3B04RKX85L5W0&psc=1&ref_=lv_ov_lig_dp_itAs an aside, here is a really nice functioning spectrum analyzer app I have on my Galaxy S9.https://play.google.com/store/apps/details?id=org.intoorbit.spectrumI'm currently working through these:https://www.amazon.com/Make-Electronics-Learning-Through-Discovery/dp/1680450263/ref=mp_s_a_1_3?dchild=1&keywords=make+electronics&qid=1592004965&sprefix=make%3A+el&sr=8-3andhttps://www.amazon.com/ProTechTrader-Make-Electronics-Component-Educational/dp/B01EKO6FZU/ref=pd_gwm_ci_mcx_mr_hp_m_0?pf_rd_s=blackjack-experiment-1&pf_rd_t=Gateway&pf_rd_i=mobile&pf_rd_m=ATVPDKIKX0DER&pd_rd_wg=7Wwg4&pd_rd_r=FNNF9BP5F7F5RKJG6NVF&pd_rd_w=RriD0&pf_rd_r=FNNF9BP5F7F5RKJG6NVF&pf_rd_p=f3f879ab-8e36-4a44-8c85-c7ce64280930&pd_rd_i=B01EKO6FZU

author: RoGeorge
author_rank: Super Contributor
timestamp: June 13, 2020, 12:27:06 am
content: If you have access to a laptop or desktop PC, there are plenty of programs that can act as a generator, or as an oscilloscope, or as both, e.g.https://www.zeitnitz.eu/scope_en

author: bdunham7
author_rank: Super Contributor
timestamp: June 13, 2020, 12:53:00 am
content: With a headphone jack. Here is how they are wired:If you have an old molded cord, just cut it, strip it and use continuity check to match the wires with the 3 sections (L, R, Ground/Common).Left goes to Channel 1 probe, Right to Channel 2 probe, ground to the probe ground(s) (you only need one).It will be less noisy if you run the tablet on battery, but if you need to it will likely work fine plugged in.Load some software, play some music, whatever. Explore your XY mode (which probably sucks, but that's digital scopes for you)