I have been doing electronic projects for more than 20 years as a hobby, but I never had the courage to go into processors and coding. You made me grab my arduino, blow the dust on it, and write a code for the first time. And it worked! I even downloaded the library for MAX7219 and tried some other codes too. I think I will like this. Thank you for your time and simple explanations, you've got one more subscriber.
Brilliant, Bora! Now that you've had a taste of success you can see what other videos you might find that are useful to you (all of them, obviously, he said in a shameless, self-promoting way, heh heh!). Seriously, the Arduino is awesome. The more I use it the more I appreciate what can be done with it. Great to have you on board, Bora.
+CJL ccc You are most welcome! More videos every week (I hope, anyway). If you have ideas for videos just drop me a comment. And do spread the word, thanks for your comments
HI Ralph- Another great video......I'd like to use this 8 digit LED to display as 2 separate 4 digit LED's to display Voltage on 1 and Current on the other. Is it possible to display variables separately?
Yes you can. Although the display is "joined", what you send to each digit (see my demo sketch) is controlled by you so you can treat it as an 8-digit display with independently controlled digits.
Hi Ralph, thanks for all of your great videos. Hopefully there'll be many more to come!...... I've been looking through your 7 segment display videos, again, in the hope of discovering the source of the black acetate sheets you once used - if my memory serves!?!? I am finding great difficulty in locating some to put over my 7 segment displays.... Can you throw some light on this, please!?
Sure can! They are not black, they are deep red lighting gel sheets and are used in the theatre. Quite cheap too, about £2 for an A4 sized sheet. Here's a typical product: www.ebay.co.uk/itm/019-FIRE-RED-Heat-Proof-Coloured-Transparent-Acetate-Gel-Sheet-Crafts-Lighting/152856102979 but you'll find them in whatever part of the world you're in, I'm sure. They really do make the red LED displays stand out very nicely.
Ralph S Bacon Wow! Superfast reply! Thanks very much for that! I'd been scouring Amazon and eBay for black acetate without much luck - so now I can finally find the correct item. Thanks again!
Thanks for all the videos. I really have learned a lot. Concerning the 8 segment modules. I cannot find a schematic. I have 4 of these and all of them behave the same where the VCC on each end do not connect to each other and the first VCC does not even connect to VCC on the chip. The other VCC does. Something is strange. Can you confirm if I have bum chips or something or does yours work that way too? AND I appear to have some sort of Ghost Power. The first module I do not even have to connect VCC or ground and it works. Very Strange.
The VCC is connected first to a diode (0.5v drop) and then to the VCC pin at the other end, Neil. Depending on how many you have in series the voltage drop(s) could be significant and probably worth connecting VCC directly to each chip rather than as a "pass-thru" arrangement. Regarding the ghost voltage, that is the power being supplied to each LED segment finding its way to other parts of the circuit. Best to avoid that happening as it is not designed to work like that.
@@RalphBacon Thanks Ralph, I now understand about the VCC. It confused me at first because both pins are labeled VCC on the board, so I thought they both are supposed to be electrical the same. In this case they are not. As for ghost voltage I am still baffled. With only DIN, CS, and CLK the display works on my project. Does your behave like that? When I connect VCC and ground to the module, my project stops working. My project consists of standalone at328p, (16Mhz method), RTC DS3231, nRF24L01+ with module, LCD module, FTDI USB to Serial to program the project, and this 7segment 8 unit module. The other end transmits the temperature from outside. The LCD was not bright enough from across the room to see the display, so I added this 7segment display unit because the red LEDs segments can be seen from across the room. What happens is when I connect the VCC and GND to 7segment module, the project stops working/receiving from the nRF24l01 module. Maybe to much current draw I am thinking? I am tempted to just leave as is, no VCC and GND to module, but I know that's not really right either. Any more insight appreciated. On different topic, not sure where to request other videos. I am thinking I would like to use PlatformIO. I also have experimented with ATmel studio 7. Not sure how to use all that simulator stuff. I too miss Benny. He was the brains of the group. He would MEOW and set you straight. His wisdom will be missed, :)
Thanks for the great tutorials Ralph! I have subscribed to your channel and look forward to watch more videos. I have made a prototype with the 7-segment display and the code you explain works great. I have a question though, how can I make it display a number stored in a variable? For example, if making a counter with a button, and showing the increasing number on the display.
+FunctionalDesign Great that you are finding the videos useful, keep watching! To display a value of between 0 and 9 (eg held in an integer) on digit 1 just change a line in the demo code like this: From: display (0x01, 0x09); To: display(0x01, [your variable goes here]); That will display your stored value (0 through 9) in digit 1 (0x01). If you have a larger value you want to display (eg 345) then determine which digits are to hold the hundreds, tens, units and send that part of the value to that digit as shown above. //Your integer value int test = 345; //convert to a byte array (aka String) String sTest = String(test,DEC); // Extract the nth digit for sending to MAX7219 display(0x01, sTest[0]); // hundreds to digit 1 display(0x02, sTest[1]); // tens to digit 2 display(0x03, sTest[2]); // units to digit 3 If the integer is large then I would do the above Extract in a loop.
Hello, today I was looking at one of your tutorial on STM32 micro's,I was amaze about the 72Mhz clock,64K memory etc,.. if I may ask, do you know any 5v logic microcontroller in the range of the STM32 , as per clock/memory similar form factor as Arduino nano,,(small and pratical) that I can use with Arduino IDE to write program, everything I worked with is 5v logic, Thank's again for all the good tutorials.
To be honest, Jack, rather than limit yourself to 5v devices (becoming rarer by the hour) why not use level shifters which are so very easy to use and ensure you don't zap your precious microcontroller. Have a look at (quite old) video #34 which describes their use: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-g3a0X30Le-8.html
@@RalphBacon Hello, and thank's for a quick reply, my goal is to design project with only 1 chip + few components on the side, since I had all my PCB's done at JLCPCB for the last 3 years. and I know about logic level shifter aka,3.3v-5v, and it's involving parts that I can do without in case I can find an Arduino IDE compatible micro cont, to fit. my main issue is the clock as to be > 16Mhz, and small footprint. for now I heve some ATTiny85,PIC12F683,690,1937,Picaxe,and of course some ATMEGA328P. Kepp up the good work you do, I really appriciate. J.B
Ralph, when you had the long code, you used CBDE7219, but when you cleaned it up, you used C8DE7219, which spells H8LP1275, just a typo. But great video, thanks. Please do one on how to take a variable number and put the digits into the code so the numbers are displayed. Thanks
You win the Eagle Eyes award for this video, Bill, well spotted (albeit about 3 years late)! Putting a variable into that message really is easy, so I will add this request to my list. Thanks for posting.
Because... you were using one of these at the time? Actually, this (early) video must have been up there about two years now so I guess you must have overlooked it! Glad you liked it though, those MAX7219 chips are excellent.
All the code has been moved to my Github repository github.com/RalphBacon/MAX7219-7-Segment-LED (all the code for videos #9, #10, #11) plus the library and extra sketch. Please let me know if you cannot access, find or use these files Paul and I'll do my best to help!
You're very welcome Paul. The thing about Arduinos is that *everyone* can make something. And it's not rocket science. (It's usually a messy nest of Dupont cables from the Arduino board to something else but that's another story.) Seriously, I'm glad you got it working and keep going - lots more things the Arduino can be used for. Thanks for posting.
No, Shaikh, not this time. Even after 3 years since this video was made, I get comments about this *typing error* ! Yes, it was a typo in my code - it works exactly as it should do! Nice to see that my older videos are still attracting viewers, though. Thanks for posting.
Sir here you have one library for that chip. It will be awesome if you make one video explaining how to use it. Keep it up with awesome videos. Good luck. wayoda.github.io/LedControl/pages/software.html
Thanks for the heads up with that library, I shall certainly take a look as I'm always interested in new ways to control peripherals. Thanks for sharing!
