I am new to the forum and I want to make a clock with and arduino and an led matrix. I wanted to make the following and change the code:
http://makeprojects.com/Project/PS-2-You+LED+Sign/1069/1#.UOhbMG8bSSo
but it seems that Sure Electronics dosent sell the led matrix anymore. I looked at adafruit.com and came across the following:
Adafruit Mini 0.8 8x8 LED Matrix w/I2C Backpack - Yellow-Green : ID 872 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
but it is more expensive and it is small for a wall clock. Can anyone assist me in what I need or where I can get one of these cheaply.
Grumpy_Mike:
Is this one big enough for you?
LED Matrix Displays | Evil Mad Scientist Laboratories
This would be great, perfect size and reasonable price. My only question is how many pins would I need to control this matrix and could I use some kind of a chip to decrease the pins needed without much work.
The MAX6953 can control 4 of those 5x7 displays using just 2 IO pins, SCL & SDA
CrossRoads:
The MAX6953 can control 4 of those 5x7 displays using just 2 IO pins, SCL & SDAMixed-signal and digital signal processing ICs | Analog Devices
Is there anything cheaper? Maybe it could only control one display would be ok. I cant really imagine spending $25 on a chip that ill probably solder wrong and it does not really look like it would go in a breadboard.
Is there anything cheaper?
Same thing on ebay?
How about the MAX7219?
Grumpy_Mike:
How about the MAX7219?
This is a perfect price. I like the led matrixs mentioned earlier but could anyone point me to cheaper ones?
Ebay it:
Will the MAX7219 work with this matrix I found on ebay?
http://www.ebay.com/itm/150961254444?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
The only reason I would ask is that the chip says common cathode and the matrix says common anode. My strong point is programming not circuits.
The MAX7219/MAX7221 are compact, serial input/output
common-cathode display drivers...
http://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf
LarryD:
The MAX7219/MAX7221 are compact, serial input/output
common-cathode display drivers...http://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf
Thanks, wow my searching skills are sure lacking today. Ill keep looking thanks for everyone's help. Just one last question does anyone have a good beginner (or advanced) circuit book that they could recommend?
What is a BOOK?
MAX7219 is $1.25 here
http://www.dipmicro.com/store/PCB-UNI30H
hard to get much less
$25 is nuts - go to maxim-ic.com and request a sample in DIP footprint. The part works very nice.
There is no difference between common cathode & common anode:
LarryD:
What is a BOOK?
I think this is going to be my book. Thanks!
CrossRoads:
$25 is nuts - go to maxim-ic.com and request a sample in DIP footprint. The part works very nice.
This looks great, a free sample is way better than $25.
CrossRoads:
There is no difference between common cathode & common anode:
Could someone else please clarify this, there is two different answers now.
Look at the 8x8 matrix - one is billed as common anode, one as common cathode - which is which? In both cases, the rows are connected to anodes, and the columns connected to cathodes.
For non-square configurations, like 5x7, you'd want to make sure the 5 anodes made up your rows (driven by the Segment pins), or the 7 anodes if wanted taller rows, with each column having a common cathode (each column driven by a digit pin).
Could someone else please clarify this,
Crossroads is right.
Thanks everyone for the help!
After skimming the MAX6953 data sheet a few times I thought of something. Do I need resistors between each screen and the chip? Does any body have a schematic. If not could some one maybe make one(Please). Also if some one told me what was needed I could make it and post it for everyone.