It's rare to find someone who not only knows electronics, but how to teach, how to speak well, and how to produce videos. I think you are giving us all something of real value. Thank you.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Rod Bhar Thank you.

Awesome project and information, im in the middle of the DC Load Project. Just finished making the PCB, my first, and got some parts soldered on while i wait for the 100E mosfets. I just wanted to thank you for all this information, instead of drooling over all the expensive equipment everyone wishes they had now we can build it ourselves. Once i finish up the DC load im going to tackle this project. Thank you once again! -Victor

@scullcomhobbyelectronics1702

6 жыл бұрын

Thanks Victor. Hope it all goes well. Regards, Louis

To me, this was one one of the most valuable tutorial videos I ever found on KZread. Many thanks for the excellent explanation about the communication between Controller and ADC. I finally got it! ^^)

@scullcomhobbyelectronics1702

8 жыл бұрын

+Eo Tunun Thanks - glad it was helpful.

Very well explained. Thanks for all your work. Great project.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Eric Gee Thanks.

Thank you so much! its been a very long time i dont have a amazin teacher, or shoud i say professor like you. I wish you the best and i will wath all your great content. Regards from Brazil

This channel is a refreshing take on what modern hobby electronics in the 21st century can do. I wish other electronics channels did more high accuracy and (or) high speed projects.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Joshua Rideout Thanks.

hello sir, i am from pakistan i have just finished watching this video and i love the explanation you provide i not in this video but so far any video of yours i have watched god bless you and stay happy always

One of the clearest explanations for the Software I have seen. Thanks.

I look forward to any updates to increase range, but this is already a great resource! Thank you very much for all your great work! Have a Happy Christmas!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Aerik Forager Thanks for your comments.

Wow, your explanation of how the code works is just amazing. Keep up the good work!

@scullcomhobbyelectronics1702

8 жыл бұрын

+zaprodk Thank you.

Merry Christmas! I cant wait to build this up! I love it that you use KiCAD as well. Take care I look forward to part 3

@scullcomhobbyelectronics1702

8 жыл бұрын

+su pyrow Thanks. In part 3 I will look at enhancements and upgrade options as well as take on board some of the suggestions in the comments so far.

The project is awesome. Both video parts were excelent: enjoyable to watch and easy to understand. Thank you very much!

@scullcomhobbyelectronics1702

8 жыл бұрын

+enguibuck Thanks for your comments.

This looks so much easier, I had a look at the 6.5 digit multimeter write up on Hackaday and it went way over my head (though it does measure more things)

Awesome as usual. Thanks for yet another very informative and useful video

@scullcomhobbyelectronics1702

8 жыл бұрын

+Tign Meg Thank you.

Excellent project!!! I really appreciate the detail. Best wishes for a very Merry Christmas!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Harvey Ellis Thanks. You are welcome.

Thanks for the nice project. Merry Christmas and Happy New Year!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Robert Calk Jr. Thanks Robert. Have a good Christmas.

thankyou so much for such detailed videos and code print out explanations! really appreciate all this effort you do. amazing videos! happy holidays!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Adil Malim Thanks for your kind comments.

Great show/project. Happy Christmas 2U2 as well.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Mooky Mann Thanks.

Great design Louis...for example the Fluke 287/289 both employ a LTC2415 sigma-delta adc.

Excelent Part 2 there, it came together very well One suggestion to the final product (Perhaps a Part 3 ??) would be to not have the 10 turn pot and use a software highend calibration instead Vishay and other makes of precision and low drift (Temp Co) resistors are quite expensive and if buying them to close tollerance ontop of that they can end up being a significant part of the cost of the whole project Buying Low temp co but lesser accurate resistors (1% perhaps) will keep the cost down and the trimming can be religated to software as typically 10 turn trimpots are not very stable devices, especially for this kind of project. Using a software calibration allows both 0 and 5V for instance to be calibrated accuratly and then useing a software determined offset (From 0) and scale factor (From 5V ref check) you can get the meter spot on (Not allowing for any none linerarity of the ADC), this results in one less component and the ability to perform the basic calibration with the complete project contained in an enclosure without having to open it. A more advanced cal could include a set of 1 V increments to eliminate or minumize the none linerarity too if so desired. Finally, connecting that pin to select between 50 or 60 Hz filtering could be connected to one of the arduino pins to allow the user to simply select the appropriate one for their region Over all an excelent example of creating a Volt meter within the budget of pretty much anyone. Keep them comming Peter (kzread.info)

@scullcomhobbyelectronics1702

8 жыл бұрын

+Peter Oakes (TheBreadboard) Peter thanks for your detailed comments, which are appreciated. I have been working of some software calibration options and could cover them in Part 3. Nice point about the 50Hz / 60Hz notch filter switch, I will look in to that.

@shana_dmr

8 жыл бұрын

+Scullcom Hobby Electronics About software calibration options, did you consider including in software the part that would inform you, that after "zeroing" the meter (pardon my bad English) the readout is larger than acceptable tolerance? Something like Datron "error 4":)

@scullcomhobbyelectronics1702

8 жыл бұрын

+kroplaaaa No. But I am looking at possible auto calibration options as an upgrade later.

Very nice project indeed. Thanks + Happy Christmas.

@scullcomhobbyelectronics1702

8 жыл бұрын

+jix177 Thank you.

+1 to what zaprodk said below... Your explanation of the code was extremely clear... Another first rate video!!! Merry Christmas

@scullcomhobbyelectronics1702

8 жыл бұрын

+Ray Reese Thank you. Merry Christmas.

Great work, I look forward to part 3!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Corgitronics Thanks.

Your really are an excellent teacher and demonstrator. I believe I have watch every minute of your videos. Some I've watched twice. I'm very new, so it's been extremely helpful. I have a suggestion for a video if you are interested.

@scullcomhobbyelectronics1702

6 жыл бұрын

Hi David, Glad you find them helpful. I am currently working on some new projects but feel free to make suggestions. Regards, Louis

Great project Louis! Will pass along your videos to some of the local techies in our ham club who designed and built a neat power meter project last year for our club's "Builders Group"; think several of the group may want to build up their own versions of your meter. 73 and Merry Xmas! Dino KL0S

@scullcomhobbyelectronics1702

8 жыл бұрын

+Dino Papas Thanks Dino.

awesome project, thanks for sharing!

@scullcomhobbyelectronics1702

8 жыл бұрын

+saturn5tony You are welcome.

Merry Christmas!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Ka Ming Cheng Thank you.

Great video and really interesting explanation as always. Many thanks and happy Christmas :-)

@scullcomhobbyelectronics1702

8 жыл бұрын

+Mark Garth Thanks.

great project keep up this great work

@scullcomhobbyelectronics1702

8 жыл бұрын

+Francois Wessels Thank you.

This is inspiring...cheers!

I'm very impressed

This could be the beginnings of a nice little bench multimeter... was wondering what to do with a large 20 character LCD I have laying around, then again, I also have nice TFT with nothing to do... ;) Could add a ultra low noise input buffer, that would allow auto calibration on power up and possibly allow some type of input protection... as for range switching, you could possibly make it auto-ranging... Too many ideas, I'll be designing in my sleep again.... Looking forward to the next one... Merry Christmas to all. Mike

@scullcomhobbyelectronics1702

8 жыл бұрын

+Michael O'Toole Thanks for your comments. Due to the number of good comments I am planning on a Part 3 to cover upgrades and enhancements.

@michaelo2l

8 жыл бұрын

+Scullcom Hobby Electronics I've build most of the circuit to test software side but am waiting for parts for the rest... I'm using the ATMega328p chip (no Arduino) and have schematic and pcb layout in KiCad (link to images)... www.phpbbireland.com/kiss2/viewtopic.php?f=80&t=1302&p=8841#p8841

Thats really impressive for a device with so very few parts, and it doesnt cost the earth, your intellegence and ability to design circuits/software so we can understand it allways impresses me, your a smashing teacher :-D I have to admit that you lost me with the software, but im not into programming so thats understandable, some bits reminded me of the old original "Basic" used in 8 bit computers, loops and print and variable statements :-) The serial data/timing in simple form made sense to even my foggy brain lol. That caddoc resistor network would be ideal for ranges, much like the resistor divider typically used in all cheap icl7106 based multimeters :-)

@scullcomhobbyelectronics1702

8 жыл бұрын

+zx8401ztv Thanks. Software is always one of the issues with modern electronics these days. I still remember when electronic hardware had no software element - which I starting in electronics it was all valves!!! Many years ago before you could buy a desktop PC, I remember making a computer with a 6502 microprocessor and only 1K of RAM and 2K of EPROM. This meant that the software was in machine code (hexadecimal format) which I use to be quite good at, but not used these days. In the early 1980's I was programming a Sinclair ZX80 microcomputer also with 1K of RAM but now in Basic language. I later upgraded to a BBC Model B Computer which again had the Basic Language but much more memory 32K RAM - thoughs were the days !!!! Now the hobbyist needs to get use to C++ which is the basis of the Arduino software code of which I am no expert but try to work it out for my projects the best I can when needed. I will be looking at range switching and other options in part 3. The Caddock resistor networks are very good but quite expensive for the hobbyist, so I also try to provide simple alternatives as well.

@zx8401ztv

8 жыл бұрын

+Scullcom Hobby Electronics I started computing with the Sinclair ZX81, i loved basic, but never went towards machine code at that time, i did repair some and made an 2k ram pack using 2114 static rams and a 74ls138 3-to-8 line decoder, worked well :-D. I got a spectrum later, i repaired them too, ram problems and the +/- 12 and 5v supplys were a problem. I learnt machine code from the table in the back of the manual, so i typed the numbers direct to memory, no assembler required. I had great fun making interfaces and i made a game cartridge, "jaysons gem" was the game i burn to eprom, worked :-D Then pc's came along and the brain stopped lol.

@scullcomhobbyelectronics1702

8 жыл бұрын

+zx8401ztv Nice to hear you had a similar experience as myself. I still have some 2114 RAM chips in a draw in my workshop!!!

@zx8401ztv

8 жыл бұрын

+Scullcom Hobby Electronics They seemed loads of memory for there day LOL mad :-)

Nice project !!!

@scullcomhobbyelectronics1702

8 жыл бұрын

+tdomingues89 Thank you.

Very nice video series, i liked a lot. Hope you are going to make more videos like this, with small projects, in the future. A sugestion for a future project could be to make a Zener diode tester, a little like this one, a boost converter combined with constant current source and a simplified voltmeter. Thanks for all your videos, i am learning a lot from them :-) Marry Christmas to you also :-)

@scullcomhobbyelectronics1702

8 жыл бұрын

+Morten Rolsing Thanks for your comments and suggestion. Best wishes for Christmas.

Спасибо большое за подробное видео.

@thecombatengineer7069

6 жыл бұрын

"Thank you very much for the detailed video." (Google translate) www.google.com/search?q=translate&oq=tra&aqs=chrome.2.69i57j69i61j35i39j69i61l2j0.1690j0j7&sourceid=chrome&ie=UTF-8

Thanks for the video.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Christian Christiansen You are welcome. Thanks.

It might be nice to have fully automatic calibration process for divider when using lower quality resistors. Instead of trimmer you maybe can measure the reference once with your Keithley and include that value in the code. After that the calibration could be done by measuring zero and the reference voltage and calculating correction from those two values.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Henri Troberg Thanks for your comments. Calibration is always an issue. I am now planning a Part 3 to this project to look at upgrades and enhancements.

Thankyou so much.

only one word wonderful

@scullcomhobbyelectronics1702

8 жыл бұрын

Thank you.

It's a great low cost project, it will be interested thing if you can add a CT or something else to it to be a 6.5 digits milliAmmeter as well...thank you so much to share this project.

@scullcomhobbyelectronics1702

8 жыл бұрын

Thanks for your comments.

In spi_read, if conversion is not finished, there's no return statement and you get garbage returned. This happens if delayMicroseconds is faster than conversion. It should work but it's not safe... Actually the test is useless because if not finished you don't wait.

@scullcomhobbyelectronics1702

8 жыл бұрын

+cyril muller Thanks for your comment. Although the software seems to work OK at the moment, I will have a look at that and cover it off in Part 3. If you are familiar with Arduino software any suggestions are always welcome.

I would have guessed that more of the declared variables would have been able to be declared with "const" like a few of them were. I also don't understand why you didn't run the calibrate routine after you adjusted the divider preset. It would be interesting to see what the level of "noise" is that gets displayed if you were to have this enclosed in something that would provide some shielding, and have a very direct "short" across the input rather than that longish clip-lead that struck me as being a usable antenna for some frequencies. I'm not remembering the details of the hardware at the moment but I don't recall much consideration being given to frequency response of the instrument, something that you might want to consider given how sensitive it can be.

Happy Christmas.............Berni

@scullcomhobbyelectronics1702

8 жыл бұрын

+berni ken Thanks and a Merry Christmas and Happy New Year.

Thanks

Hey! How are you holding up? I think one of the best uses for this one would be combining it with the milliohm meter and adding high impedance front end.

I really enjoy watching your videos. Your good. I'm trying to teach myself about electronics over the internet & was thinking that this meter might easily be converted to an accurate ammeter across a sense resistor. What do you think? am I on the right track? If so, what value or values would you suggest for the range of this meter? Thank you, Todd K.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Todd K. Thanks for your comments. In theory you could do what you are suggesting. Using a 1 ohm current sense resistor and measuring the voltage across it would equal 1 mV for 1mA. To read micro-amps a 1 ohm resistors would only give 1uV for 1uA - which is beyond the limit of this Millivolt Meter project. Ideally you should use a sense resistor of milliohms but this would not be practicable with this Millivolt Meter. You could use a bigger sense resistor but this is not really recommended. As the benefits of a low value sense resistor are: 1. Low value resistors have better time and temperature stability, and a better voltage coefficient than high value resistors. 2. Low resistor values reduce the input time constant and result in faster instrument response times. Noise is also an issue at very low currents. There are two basic techniques for making low current readings - the shunt method, and the feedback ammeter technique. The shunt method is used primarily in Digital Multimeters. Whereas, Picoammeters and newer Electrometers use only the feedback ammeter method. I think building your own low current ammeter is for another project !!!!

@toddk.5873

8 жыл бұрын

+Scullcom Hobby Electronics Thank you for taking the time & sharing your knowledge. You are a true gentleman. Todd K.

Great videos! I just wonder, wouldn't taking several measurements and then do an average on them? Would that not stabilise the value and make it more accurate?

@scullcomhobbyelectronics1702

8 жыл бұрын

+Jack Zimmermann Thanks. Yes averaging does help and this project does in fact take a few reading and then takes the average.

bravo!

@scullcomhobbyelectronics1702

8 жыл бұрын

+First2ner Thanks.

Thanks so much for the video. I would like to know if it can be programmed in labVIEW. If yes, how can i do that. Thanks.

@scullcomhobbyelectronics1702

8 жыл бұрын

+Abel ke Yorke Sorry I have not used National Instruments labVIEW as yet.

@AbelKEYorke

8 жыл бұрын

ok. thanks.

What would happen if the input polarity was reversed? Would it hurt the circuit or simply show a negative sign?

@scullcomhobbyelectronics1702

8 жыл бұрын

+Rachel L The diode D1 at the input would clamp on negative input and protect the circuit (see schematic). I am also looking at other alternative protection measures I will try and cover in Part 3.

@Rachel801

8 жыл бұрын

Ah, I guess it would. I saw that diode but assumed that it was only there to clamp the input to 5.1 volts. Thank you.

What was the source of the noise in the reading? Was it the voltage standard or something else?

@scullcomhobbyelectronics1702

8 жыл бұрын

+Gooberslot Noise can be caused by a number of things which could include voltage reference noise, ADC input noise, power supply noise, external EMI noise, etc. I will have a look at that in part 3 of this project.

@Gooberslot

8 жыл бұрын

Scullcom Hobby Electronics I'm looking forward to part 3.

This is a good project. But it's not really a 6.5 digit, it's more like 5 digit at best because of the noise floor. Maybe getting a lower noise LDO than a 7805 could help. Or a better op-amp.

This may be a stupid question, but, why is it always " a number" and a half digits when describing 7 segment displays?

@shana_dmr

8 жыл бұрын

+Donovan Lym It's sometimes 3/4, not half;) If your meter can display 0-1999 then it's 3 1/2 digits - three digits (0-999) and one that can be only 0 or 1.

@donovanpl

8 жыл бұрын

+kroplaaaa well, that makes sense. Thanks.

Ow man. I really like the project and all the component research was great. But the program has so many flaws and bad practices in it it's terrible to watch! When I'm back at my computer this weekend (all I have now is my One Plus) I'll rewrite the program. I'm glad you would like to make a third part of this:)

@scullcomhobbyelectronics1702

8 жыл бұрын

+tengelgeer Thanks for your comments. Arduino software is not my forte so any help with a better programming solution would be much appreciate as it would also help others. I am planning a Part 3 of this project.

@RobeenaShepherd

8 жыл бұрын

+Scullcom Hobby Electronics You certainly have an "interesting" approach to code formatting. ;) I've seen arduino code before, there does seem to be a lot of global variables in it, I guess that comes with the territory. Btw, pretty much anytime an operator that acts on a left hand side (LHS) variable, it can be written as operator=, so x = x + 13; becomes x += 13, x = x / 10; can be written as x /= 10; Doing this makes code a little easier to read and helps develop a comfortable level of OCD. This must be what its like for hardware engineers when us software engineers start laying out boards!

@scullcomhobbyelectronics1702

8 жыл бұрын

+Robee Shepherd Thanks Robee. As I was trained as a hardware electronics engineer, software is not my first discipline, coding does not always come easy!!! Thanks for your help. Arduino code at times seems to be a law to itself, there are so many variations!

In your software you are converting to float too early. This gives you an computational error which might be the reason why you get about 20-50 uV offset for 0V still even calibrated. change lines: volt = sum; //result changed to a float type and named volt (represents number with fractions) volt = volt * 10; //muliply voltage reading by x10 to adjust for input resistor divider network volt = volt * v_ref / (16777216); //convert reading in to Volts ready for the display (max scale 24 bit number) to: sum = sum>>12; //this is equivalent to 4096/16777216 which is 2^12/2^24 = 1/2^12 which in turn is shift 12; 4096 is vref times 1000 volt = volt / (100); // factor 1/1000 from the above operation times 10 from the divider network; division by 10^x better made in float, because binaries don't like it ;-) Anyway a very nice project!

@scullcomhobbyelectronics1702

7 жыл бұрын

Many thanks for your comments on the software. I will look in to that and test it. I will shortly be uploading an update to this project so will test it out on that. Regards, Louis

What would happen if you use an even lower noise voltage reference like this one: waltjung.org/PDFs/Build_Ultra_Low_Noise_Voltage_Reference.pdf Also I noticed that the reading now has a much slower update rate then reading showed in the first video. Was this intentional? Anyways I love this project and can't wait to make my own PCB's :)

@scullcomhobbyelectronics1702

8 жыл бұрын

+Ventsislav Simonov Any method to reduce the noise will benefit the meter reading. In Part 3 of this project I will look at the noise levels. Following comments I did slow down the update rate in the software to make the reading more stable. But if required this could be change to make it faster. Thanks for your comments.

Great Project? But no shematic and no PCB!

@scullcomhobbyelectronics1702

6 жыл бұрын

You will find I have given some download links in Part 4 video of this project. kzread.info/dash/bejne/lGZ5stmzhcaToNI.html Also the download links are below for you: www.scullcom.com/Millivolt_Meter_Ver4.pdf www.scullcom.com/Millivolt_Meter_PCB_Ver4.pdf Also below is a download link for the KiCad files for this project. www.scullcom.com/MilliVolt_Meter_Part4_KiCad_Files.zip If you are thinking of building this project then I recommend you view all parts of this project prior to building. Regards, Louis