Function/Waveform Generator || DIY or Buy

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Check out Cezar Chirilas article on All About Circuits: www.allaboutcircuits.com/proj...
You can get the commercial function generators here (affiliate links):
Siglent SDG 2082X: rover.ebay.com/rover/1/711-532...
AE20125: rover.ebay.com/rover/1/711-532...
XR-2206: rover.ebay.com/rover/1/711-532...
More project information (schematic, pictures,.....) on Instructables: www.instructables.com/id/DIY-...
Parts list (incomplete, see Instructables for more, affiliate links):
Aliexpress:
1x 12V center tapped transformer: s.click.aliexpress.com/e/_dZz...
1x IEC socket: s.click.aliexpress.com/e/_dYQ...
1x B40C2300 full bridge rectifier: s.click.aliexpress.com/e/_dUS...
1x LM7812 12V regulator: s.click.aliexpress.com/e/_d8G...
1x LM7912 -12V regulator: s.click.aliexpress.com/e/_d6u...
1x LM7805 5V regulator: s.click.aliexpress.com/e/_dWI...
1x Capacitor kit: s.click.aliexpress.com/e/_d8N...
1x Arduino Nano: s.click.aliexpress.com/e/_d85...
1x Rotary Encoder: s.click.aliexpress.com/e/_dXK...
1x AD9833 DDS IC: s.click.aliexpress.com/e/_dTc...
1x I2C LCD: s.click.aliexpress.com/e/_d6H...
1x TL071 OpAmp: s.click.aliexpress.com/e/_dXd...
1x BNC connector: s.click.aliexpress.com/e/_dZ5...
1x 10k, 50k Potentiometer: s.click.aliexpress.com/e/_dU8...
In this episode of DIY or Buy we will have a short look at commercial function/waveform generators in order to determine what features are important for a DIY version. Afterwards I will then show you how to create a simple function generator, the analog and digital way. At the end I will then present you a DIY DDS function generator design which can (kind of) hold up to the commercial versions. Let's get started!
Thanks to JLCPCB for sponsoring this video
Visit jlcpcb.com to get professional PCBs for low prices
Music:
2011 Lookalike by Bartlebeats

[@alenasenie6928]

-"it did't result in an explosion, perfect" Electroboom disaproves

[@reggiep75]

Nice to see someone out in there thinking like me. ElectroBOOM's soul cries in pain until he can murder some capacitors.

[@Scorry]

Every time happy while first turning on without BOOM.

[@pyrojason]

-(Audience)- "Awww...."

[@mkbharadwaj4560]

ye lmfao

[@ZoniaTV]

I've been wanting to build my own function generator for a while now. Thanks for posting this.

[@greatscottlab]

You're welcome ;-)

[@mathiasbackof4993]

@@greatscottlab ; - )

[@meepk633]

Seems like a good way to learn about a few things like op-amp scaling, DAC control and UI development. I'm designing a fantasy one right now. Then I'll do one I can actually build.

[@Jay-fp8iy]

@@meepk633 Post up both pls

[@patprop74]

Likewise, maybe this is the one to build.

[@Dak47922]

"This picture may seem complicated.... but if you study this 21 PAGE DOCUMENT it becomes pretty simple." heh

[@TheMadPhilosopher]

That's a pretty small price to pay for knowledge.

[@jtb8631]

The Mad Philosopher do you just wander around deflating other people’s humor with trite remarks?

[@power-max]

believe me that's nothing. Just read a user guide for any modern micro-controller or FPGA. This user guide for the classic STM32 is over 1000 pages. And it is a low-end chip. The F4, F7, and H7 are gaining popularity in the DIY space now mostly because of more flash space. www.manualslib.com/manual/1276772/St-Stm32f101-Series.html#product-STM32F103%20series

[@SimonBauer7]

i hope you never study anything then, because each script you get there is houndreds of pages, 21 pages is a joke.

[@mackdlite5900]

Your DIY or Buy is my favorite KZbin segment. I always look forward to these. Great job!

[@Miata822]

Awesome! This goes on my (already long) project list.

[@Stoneman06660]

And the list is long, and the know-how lags the list! 😆

[@innovation4u336]

You are great teacher. I always wait for your video. Keep up man....

[@greatscottlab]

Thanks :-)

[@skittermckitter05]

Obviously very late, but the instability and other issues at high frequency are likely due to the construction of the op amp portion of the circuit. Very good decoupling is important, and the output of the op amp should be followed by a resistor so that the transmission line is double terminated (therefore protected from bad loads) and any capacitive loads don't cause phase margin issues.

[@lifeselectronic]

I saw a lot of different videos on KZbin about this topic,but everything seemed to be very complicated Your video was the most simple but yet the best one i come across Keep it going :)

[@greatscottlab]

Thank you very much :-)

[@bpbrainiak]

Always enjoy your videos! Saying hello from Santiago de Chile

[@GarageScience]

A waveform generator has been on my want list for a very long time! One of the first comments!!!

[@settwi]

I really like your content, and I appreciate how clear you are with your whole process, especially the analysis of data sheets and circuit diagramming. Thank you!

[@ahmedelmazaty9459]

Thank you for this project. I am looking for this for along time.

[@popcoron11]

素晴らしい語り口。引き込まれてしまう。wonderful narrative. I am drawn to the charm.

[@stevetobias4890]

Really like the DIY or Buy episodes

[@ithaca2076]

I've been waiting for this!! nice

[@krystian_rla]

nice project ,you could use AD9851 or AD9850 for higher frequency ,btw it should be possible to modulate signal eg. AM or FM ,it may be useful

[@MCsCreations]

Fantastic work, dude! 😃 I may make one some day! 😃

[@SemproniusDensusGaming]

I would like to see a video about CAN Bus Systems. Thumbs up for the video man

[@greatscottlab]

I can put it on my to do list

[@id15807936]

@@greatscottlab There are libraries for MCP2515 chip for Arduino IDE and there is also a library for using it with CAN Hacker software. Yesterday I tested it out on my STM32 Blue Pill board by using stm32duino and it works great! sun9-69.userapi.com/c857420/v857420683/714f7/aM3nLdigq48.jpg STM32 Blue Pill also has CAN bus support itself so it doesn't even need chips like MCP2515, it only needs CAN tranciever such as TJA 1050.

[@electronic7979]

Excellent video. Very helpful

[@robertsmiczsmiczamplificat593]

Great video. I love all your videos. Thank you.

[@erygion]

Great video as usual :) I have a XR2206, the same one in the video(very common I know) and it work fine for now but if I ever need an upgrade I'm doing this. Thank you sir!

[@prashanthb6521]

I simply enjoy your videos even if I have no plans to build this circuit.

[@v.vincent6631]

Simple and superb function genatator at cheapest prices..👌👌👌

[@shoumikahmed6373]

I was looking for this ...Thanks a lot.

[@goofypettiger]

This was epic. Thank you for sharing it.

[@TheCalebf]

diy is always the winner as knowledge is priceless and indefinitely replicable

[@pauljackson2126]

Finally, a project and a good lab instrument for Electronics Hobiests....

[@jacoblanctot2335]

Sweet! Thanks for making this. I think I can use something similar to this for my research doing phase shift keying.

[@arafatal-gharabi7066]

Even though that it's difficult to understand but I like to watch your videos

[@edslab5383]

Nice video! I'd like to see in a future DIY or buy episode an RLC meter.

[@BoernTilStede]

love this series man :))))))

[@sarkam73]

Very good video You are great elektronik teacher

[@danielstellmon5330]

I love this channel. It inspires me to persue the hobby. Unfortunately, or perhaps fortunately, I understand I will never take my skill to his level. I just want to build a custom keyboard and a programmable universal remote.

[@rogerfurer2273]

FYI: AD9834 is a faster DDS. Also a ground plane may help w/noise and stability. Nice video, I appreciated the information. Thinking about DIY to upgrade from my 40 year old Circuitmate.

[@baskabisi453]

I love your diy or buys

[@JatSingh]

Hi Scott. I think a great video would be basically a video focused on the parts you usually skip on the videos. So for example let's say you choose something simple like a power supply diy build. Go through step by step buying and ordering the parts. And the soldering as well. Maybe 3d design if it applies for the project

[@naknakacknak]

This is really a nice project. I bought a used Philips/Fluke PM 5191 Programmable Synthesizer/Function Generator for $85. It's 0.1 to 2 MHz. Interesting device.

[@PlasmaHarsh]

Hi I'm your biggest fan. I always wait for your videos💜💜

[@greatscottlab]

Thanks :-)

[@crazyphil7782]

“One point five years ago” that had me laugh some

[@GreyDeathVaccine]

Nobody talks like that :-)

[@sobertillnoon]

Holy crap. This video is perfect. I was just researching the xr2206

[@greatscottlab]

Thank you. Glad you like it :-)

[@Dragoby]

I really like this series as I really like to do diy over buying things. I think a diy or buy on a UPS for a future video idea!

[@johnford7847]

This will be useful - I need several inexpensive function generators for our electrochemistry lab. I hadn't seen anything over 100 kHz. (I confess I hadn't searched in the last five years.) Thank you.

[@hafizdr]

I really like the way that you said when you "stole" his code to "save time and effort"

[@sincerelyyours7538]

Nice one! I bought a $50 Chinese DDS function gen a few years ago and found navigating its menu frustratingly cumbersome and its outputs distorted, full of hash and ringing badly. You get what you pay for, I kept telling myself. I then replaced its two output op amps with ones having a better slew rat, per some online videos I found, and got better looking waveforms with less ringing, though they're still not lab instrument quality. In the end I probably spent too much for a cheapie DDS function gen but the experience taught me a few things about how these things operate.

[@lsudan2670]

what ever u recommend , I really enjoy your videos Scot also your voice sooths me 😌😉 you're amazing 🎊🎉 keep doing cool stuff and your #like is coming from ma heart ! hugs from Greece 🙋🙌...stay creaaaaaatiiiiiv an' I wiiilll seeeeee uuuuu next time 😀😁😉

[@laurentiudragomir1091]

Cezar Chirila, bravo si salutari!

[@lukahierl9857]

The squarewave output of those cheap nasty red functiongens alsow works as a sine wave above 100khz

[@Rainbow_Sword]

Just reduce the amplitude of the wave and it should look more like a square wave because of reduced time for charging external capacitors

[@abdulazeez.98]

Lol, that's an additional feature .

[@TheAzther1]

I think the reason of the malfunctions of these generators are fake IC's, I remember seeing a video of a guy replacing it with a legit one and most problems went away. Of course even original ones have their own limits so there's not that much else it can be done about it

[@krissolshaq4934]

@@TheAzther1 the main reason is shitty op amps with poor slew rate and crappy pcb design. It is not the frequency of the waveform which is the problem. Look at edges of the squarwave. They have to be super fast to reliably generate a square wave. 10MHz squar wave requires edges to rise and fall in like 10ns to keep the signal look like a square wave, not a sine or trapezoid. So to have 10Mhz squarewave you need an op amp with 100MHz bandwith. However, you want to use the op-amp to amplify the waveform, so to have a decent waveform at the output and also a gain of 10 you would need an op-amp with at least 1GHz gain-bandwith product and 100 000 000V/s slew rate to give you 10V p-p voltage. Good luck with that.

[@avejst]

Fantastic project Thanks for sharing 👍😀

[@frosty129]

I bought the UDB1008s 8Mhz function gen from aliexpress for 20 bucks. It does very clean 7Mhz sine, and okay 700kHz square and triangle, with sawtooh and pwm support. Perfect for DIY.

[@trentjackson4816]

DIY will always be the ☆Winner☆ - for when it comes to test gear.

[@loganfansler9211]

Awesome video AS ALWAYS! I think it would be awesome if you could do a DIY-OR-BUY on TL-smoothers used to remove the salmon-skin effect on 3d printed parts. Seems like a quick project that would be really interesting! Thanks for all of the great content!

[@armandine2]

I love the way you say potentiometer.

[@MrConnor128]

Another great video! Thank you!!!

[@Twometer]

What kind of filament did you use for the box of your Function Generator? I really like how it looks

[@lukaswalczak93]

Great work. You should have designed a PCB with good RF characteristics in order to achieve much better High frequency performance. Additional Filter circuits on the in- and output also would have made a significant difference. Also choosing a low noise op amp on the last stage is mandatory. Anyway great project!

[@gudenau]

Oh my, the DDS is very clever. I like it.

[@sanmvegs1641]

To have better performance at high frequencies, you should used opamps with higher gain bandwidth products (GBP). Because the DDS would not give wrong signal it is only the mistake of signal processing. It seems that you are using TL071 opamp which has GBP of 5.25Mhz and you are using it to amplify by a factor of 22, so the bandwidth of this configuration of opamp will give you a reliable signal bandwidth of around 23 khz

[@allonet622]

As always magnificent, 💜

[@excitedbox5705]

I love your build vs buy series. Couldn´t you expand this to give you an arbitrary function generator if you added a keypad to the Arduino to punch in voltages?

[@ADR69]

Thank you, Cesar!

[@ninaddeshmukh654]

Ever time I see ur videos notification I hope for the drone video hoping the day comes soon

[@greatscottlab]

Not soon.

[@thelitecommando]

Love the project, just a reminder that 123D is discontinued and basically superceded by Fusion 360 (which is also free for hobbyists, students, and small startups).

[@Drxxx]

amazing project, which filament did you used?

[@hannescamitz8575]

Oooh! New colours of the markers!

[@jeromyashcraft4571]

Wow. Great video. Thank you.

[@santanumukherjee1548]

Amazing Explanation.

[@nixma4613]

Love your channel!

[@greatscottlab]

Thanks you :-)

[@wimjongman]

Nice one. Thanks Scott.

[@eebaker699]

Great video!

[@SimonCoates]

FY6800 DDS Signal Generator/Counter is amazing value for money - worth a look for anyone considering a budget unit.

[@Adrian_Finn]

One of the problems with those is the crappy Switch mode power supplies that have been fitted inside them, which is not what you need with a sig gen, people have modded them very easily with linear power supplies though so not all bad. Few good channels on YT cover this.

[@todayonthebench]

@@Adrian_Finn The noise from the switch mode power supply is though far from bad on the units. Since it gets drowned by the harmonics from the signal generator itself. Also, a linear power supply will generally couple through all the noise from one's mains wiring, so have a computer or other switch mode powered device connected nearby and you will have just as much noise from the linear supply. In any case, the issue can easily be rectified by adding a bit of extra output filtering from the supply, not that this matters much due to the signal generator already having enough harmonics and other crap that it literally drowns the noise from the power supply. (In the end, I wouldn't recommend practically any DDS for RF use, obviously.)

[@SpeccyMan]

The real issue with these devices is the floating AC on the earth side of the BNC connectors (measured with reference to a true earth.) Not enough current behind it to harm you but more than enough there to fry the delicate inputs to a microcontroller.

[@SimonCoates]

@@SpeccyMan You seem to be referring to the FY6600, not the FY6800.

[@todayonthebench]

@@SpeccyMan This is indeed a problem. I solved it by adding a wire going over to mains earth. Seemed trivial enough. Though, to an exceptionally small degree, one could regard the non-earthness of it as a "feature", if it weren't for the huge amounts of common mode noise...

[@DynoRC]

Nice project after a "while"

[@RealCousinOkri]

I've been trying out an AVR microcontroller with an R2R DAC and well, it kinda worked. Needs some polishing though, as adjustable offset and amplitude can be useful. It seems like a must have for a guitar pedal enthusiast, at least for me.

[@StitchesLovesRats]

Mate, I gotta say, I frikkin love you for these instructable videos. I've already built an audio amp that works real good thanks to that vid and project page. You ever consider compiling a library that can be put on an internet in a box?

[@blackwingmaster141]

TL071 is not suitable for 10MHz signals,and that's why your freq. gen. deos not work properly at high frequencys. Also, I don't see any decoupling capactors (approx. 0.1uF) near IC power pins. Using high frequency opamp and adding decoupling caps should fix high frequency issues

[@ObligedTester]

Great info, thanks! Any recommendations for OP-amp?

[@HRTtwitch]

@@ObligedTester I know this comment is from a while ago but as I just looked at this based on other comments in this thread this might be helpful for others. Find something low noise and high speed (select this based on your desired max frequency). You may want to consider slew rate as well @w2aew has a great video that explains slew rate and gain bandwidth product for opamps on his youtube channel that will help.

[@yagneshpatel1183]

TL071 IS AUDIO IC NOT FOR INDUSTRIAL GRADE . BETTER SWITCH TO MCP SERIES IS BETTER

[@electronichannelgreece]

@@yagneshpatel1183 friends I bought this operation amplifier!!!!Still I have not received any of my items about this project!!!I wanna make this project in 5volts!!!I have dc-dc converter from 5volts to 12volts (the MT3608) and I have the converter from 12volts to -12volts...At first I worry about the output signal voltages because I made my own serial oscilloscope with arduino and the max input is in 5volts and I want to control the output voltage

[@felipealves921]

lm6171 it's a good option

[@jimday666]

Epic! more on this show!!!!

[@melplishka5978]

Ty. Great vid. My next project lol.

[@lensherman6242]

FY6800 from Banggood and others is about $90 US. 60MHz 20Vp-p output with a decent display and a normal case.

[@ortani]

No way... Amazing! 🎉

[@danielstandley-Physicist]

Thanks for posting this I has given Ideas to make something similar

[@stephenbrown5999]

Beautiful I love it.

[@muavains]

I am very big fan of you. Please make a video on your Electronics lab.

[@albertomora4462]

It would be great to create a function generator with also sine sweep and random noise signals.

[@SDinnovation]

i have build it & it worked fine , thanks.. however how much max amps it can give output ?

[@AstrobumTV]

Please do a video about whether should one build a diy 200MHz oscilloscope or just buy one.

[@UpLateGeek]

It'd be interesting to troubleshoot the issues you saw at higher frequencies, to try and get the maximum performance out of this chip. And to me, the MVP (minimum viable product) would also have variable duty cycle, at least for square wave. That way you can also play around with PWM stuff (and it would match the features of the function gen in my oscilloscope). Without looking at the datasheet, I'm not sure if the chip will do this without any extra hardware, but I do know you can generate PWM signals from a triangle wave using a comparator.

[@norm1124]

Danke für das Design, ich werde es wohl mit 2x 9V Batterien nachbauen.

[@Rolly369]

have a look to the JDS6600 function gen, it Outputs up to 20V+/- and easy up to 16MHz and it can do programmed waveforms… cost appx 60$

[@georggross1232]

YaY! DIY beats again!

[@witrc6801]

You are clever. You can all of electronic. Good luck.

[@radionorwick5011]

good stuff, thank you sir.

[@johnavonvincentius1884]

Definitely A Project That I will build..

[@greatscottlab]

Awesome!

[@maatsche]

Very cool!

[@skifyfoxes]

Nice video

[@jamilf84]

Scott, Thank you so much for this tutorial. I do have a request if you dont mind. I signed up to all about circuits so i can download the code. But every time i click to download the zip file it takes me back to the home page. Do you have the code somewhere on the web for me to download?

[@ZAProjects]

Nice, I can Try to build my own!

[@robdavis3220]

You should add a low pass filter after the DDS chip. Maybe a 15MHz or so LC ( or higher order). This will improve the the signal output at higher frequencies.

[@DJAlsip]

Hi Scott, quick question: The transformer you suggest is designed for 120VAC on the primary side, whereas here in Europe we have 230VAC mains. I don't see a center-tap on the primary coil to make it dual voltage, thus theoretically the output should be approximately twice of the rated voltage for the secondary (ie. 2x30VAC instead of 2x15VAC). Am I missing something here?

[@eimparas]

heeey ! the ad9833 part you ued in easy eda , was made by me ! xaxax im proud tho see it fetured in your video !

[@greatscottlab]

Haha thanks for your good work :-)

[@eimparas]

im in the prosses to create my own fully digital controlable dds fg

[@pupunmohanta165]

Super video

[@mohamedgamalyousef8991]

great project i was waiting for it until I found another DIY function generator on google which contains more functions than your version like saw tooth or ECG or noise with R2R DAC but it's maximum frequency is 0.65 MHz so i think both are good