Maxim 7219 Eagle PCB & iTead files for Adafruit 0.56" 7 segment clock display's

I love the Maxim 7219 chips… Amazing value for money (5 euro’s for a genuine chip)
And I love Adafruit: great products and great support (I am not supported by them :wink: )

For my DCF77 Radio clock project, I need a LOT of 7 segment displays but I could not find what I want.
So I made in Eagle CAD a PCB to suit my requirements and to fit the Adafruit 0.56" clock 7 segment displays

GITHUB: deruiter (Erik) · GitHub

I want to make the PCB files available to others but what is the best way to do that?
[EDIT] :astonished: @JoeN: I did not realize that the files are so small, I can indeed attach them here…, thanks!

Pinout labels to glue on the Maxim 7219: http://forum.arduino.cc/index.php/topic,231729.0.html

The Eagle CAD 6 files AND the ZIP file to send to iTead are attached in a ZIP file <Maxim72197segmentBoard.ZIP> below

Can't you just zip them up and attach them here?

I like those chips too, though chips with PWM functionality are really a lot more capable. 7219's are available on eBay at 'fell off the truck' prices of well less than $1 USD each delivered.

www.ebay.com/itm/25PCS-IC-MAX7219CNG-MAX7219-DIP-24-DRIVER-LED-DISPLAY-8DGT-NEW-GOOD-QUALITY-/290746404262

edr1924: I love the Maxim 7219 chips... Amazing value for money (5 euro's for a genuine chip)

Are you sure they are genuine at that price? Its easy enough to spot the genuine ones if you know what you are looking for.

http://www.picaxeforum.co.uk/showthread.php?22481-Real-or-fake

Paul

@PaulRB:

Hi Paul, thank you for pointing this out but yes I did know about the fake Max7219's... If you look at the photo above, you see at the top the Original Maxim and below the fake model.

As mentioned in the link you provided, the most important giveaway is the lack of the DOT at pin 1 and the SHORTER CHIP housing on the fake Maxim 7219's

I do not know if it is allowed here to reveil the name of the firm I bought the originals for 4,75 euro's? Before purchasing, I emailed them and asked if they sell original chips and they did confirm they sell only original brands

I used also some fake models but when I daisy chained 5 chips, each with eight 7 segment displays, the high pitched sound they produced was unbearable! The solution in my case was to connect a large 470µF capacitor on each PCB. I still need to test if the original Maxim 7219 chips will stay silent with the usual 10µF chip already mounted on the PCB.

So I figured I will use original brand chips because I will make a clock for my bedroom and I DO want to sleep... ;)

JoeN: I like those chips too, though chips with PWM functionality are really a lot more capable. 7219's are available on eBay at 'fell off the truck' prices of well less than $1 USD each delivered.

www.ebay.com/itm/25PCS-IC-MAX7219CNG-MAX7219-DIP-24-DRIVER-LED-DISPLAY-8DGT-NEW-GOOD-QUALITY-/290746404262

Hi JoeN, which are the chips with PWM, do you mean the 74HC595?

Thanks for your tip about the cheap 7219 and I do own 10 of them but see my reply above why I use the originals now... ;)

Well, the people who run the PIXAxe forum are a bunch of (redacted) and you can't even view the attachments without registering and there is no automatic registration, every registration must be OKed.

I bet I have fake chips, then. Other than the 10 or so I got directly from Maxim as samples. Funny thing, they work fine and I have used as many as 20 of them in a single project. I don't get noise out of them. In fact, I wonder how you could get noise out of them other than as EMF which manifests itself somewhere else, like on your computer or radio as sound. These chips do so little I wonder how Maxim can price them like they do. On the other hand, I wonder how the Chinese company cloning them can afford to sell them for 50 cents. There can't be that much demand for fakes, right, other than the hobbyist market which we know is tiny.

For PWM chips I mean chips like the TI TLC5940 and Worldsemi WS2803. These chips you give each channel a value for its output (10 bit for TLC5940 and 8 bit for WS2803) and it sends that duty cycle to the LED. So it works to dim the LED and allows you to mix different levels of red, green, and blue for RGB displays to get "full color". But you have to do the multiplexing yourself. That is what the MAX7219 will do for you that simplifies your code quite a bit.

Sorry joeN, I was forgetting non-members can't see pictures on picaxe forum. But edr1924 is correct, by my understanding, those are real maxim chips. The pin 1 dimple is the simplest tell-tale.

PaulRB: Sorry joeN, I was forgetting non-members can't see pictures on picaxe forum. But edr1924 is correct, by my understanding, those are real maxim chips. The pin 1 dimple is the simplest tell-tale.

Hey, no problem at all. I will wait patiently until they finally OK me. I'd like to see the images. Though, I do have the cheap 50 cent Chinese sourced chips (almost 200) and ten ones I know are real as they came directly from Maxim (thank you, Maxim, for your generosity). I think I will simply pull them out and look at them under the microscope.

Hi JoeN, I came across some very nice pictures of Real and Fake Maxim chips (the inside)

I made a separate thread: http://forum.arduino.cc/index.php?topic=233109.0

JoeN: For PWM chips I mean chips like the TI TLC5940 and Worldsemi WS2803. These chips you give each channel a value for its output (10 bit for TLC5940 and 8 bit for WS2803) and it sends that duty cycle to the LED. So it works to dim the LED and allows you to mix different levels of red, green, and blue for RGB displays to get "full color". But you have to do the multiplexing yourself. That is what the MAX7219 will do for you that simplifies your code quite a bit.

@JoeN: Those are nice chips...! I will deal with them later I think because I love LED's also 8) But I just begun with Arduino and C programming so I have a lot to learn so the Maxims at this stage in my (steep!) learning process are the best to use for my clock project...