Jan09 - 16x16 Tri-colored LED matrix Real Time Clock

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tdg8934
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Jan09 - 16x16 Tri-colored LED matrix Real Time Clock

Post by tdg8934 » Wed Jan 07, 2009 2:20 pm

For those interested:

The first set of items in the parts list are from Radio Shack as it was not listed.

Go here to get the software, documentation, etc:
http://forums.parallax.com/forums/defau ... 1&m=189908

Since the SX52 proto board is now obsolete, you may be able to buy a lot of 10 min. from Mouser. However, I am working on a newer design that will allow for using the SX48 but it will probably not use push buttons as you can program the date and time with the SX-Key or SX-Blitz programmer. I will have to think if there is a better way. Let me know if you have any questions.
Tim Gilmore
[email protected]

Bigglez
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Re: Jan09 - 16x16 Tri-colored LED matrix Real Time Clock

Post by Bigglez » Thu Jan 08, 2009 1:09 am

tdg8934 wrote:I am working on a newer design that will allow for using the SX48 but it will probably not use push buttons as you can program the date and time with the SX-Key or SX-Blitz programmer. I will have to think if there is a better way. Let me know if you have any questions.
Enjoyed your project and article!
I would have liked to see some PIX of the
inside of the finished project.

tdg8934
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Post by tdg8934 » Thu Jan 08, 2009 3:53 am

Thanks Bigglez for your kind words.

When I first designed this project I did some point to point soldering on the (4) 8x8 bi-color (tri-color) LED matrixes as well as used Radio Shack perf boards with more point to point soldering the wiring is a bit messy but fully functional. I beleive there was one perf board for the (4) LED matrixes (that were offset positioned on the board but ok to tightly fit next to eachother -left / right / up / down. I then included the ULN2803s on that perf board but I had to make a custom PCB from Radio Shack etched kit for the 16 P CH FETs. I had used a doublesided board with 8 on each side. I soldered 22 guage wires to the pads and ran the wires to the LED Matrix / ULN2803 perf board. I also had a 3rd board (perf) that had the LED control ICs (74HC573) I believe. Finally, I can't remember but originally it was going to be programmed via the SX-Key for date/time but since I had extra I/O, I decided to add a 74HC165 for up to 8 pushbuttons for programming control. I realized later that since I only needed 3 pushbuttons for time/date change up, time/date change down and time/date set, that I had enough I/O on the SX52 but since I already included the 74HC165 I left it in - for future expansion of pushbuttons or something like that. The article photo shows 4 pushbuttons but only 3 are needed. Lots of room for change.

That leads me into my next outlook, if there is enough interest (which there has been some), I am going to redesign this project for an SX48. It is not going to be easy because of the lack of 4 less I/O pins but should be possible. I am looking at adding an SX28 as a slave to the SX48 to handle the LED color control I/O signaling and possibly the pushbutton control. This should remove some extra hardware (ICs) and put more control into the slave SX28. I am also going to look at designing a PCB to mount everything too except for the SX48 protoboard but that may be possible too - who knows. Check out the Parallax completed projects for updates in the next few weeks/months: http://forums.parallax.com/forums/defau ... 1&m=189908

Tim Gilmore

Bigglez
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Post by Bigglez » Fri Jan 09, 2009 1:51 am

tdg8934 wrote: When I first designed this project I did some point to point soldering on the (4) 8x8 bi-color (tri-color) LED matrixes as well as used Radio Shack perf boards with more point to point soldering the wiring is a bit messy but fully functional.
Yes, I can relate. I've recently completed a digital
clock POC (Proof Of Concept) using the LED tiles.
Here's a quick PIX:
Image

Image
tdg8934 wrote: That leads me into my next outlook, if there is enough interest (which there has been some), I am going to redesign this project for an SX48. It is not going to be easy because of the lack of 4 less I/O pins but should be possible. I am looking at adding an SX28 as a slave to the SX48 to handle the LED color control I/O signaling and possibly the pushbutton control.
I only have three IO pins form the AVR uC for all
210 LEDs. A couple more for the switches, and two
for the RTC and EEPROM (latter not wired up in the
PIX). I was wondering from your published article
why you needed so much IO?

tdg8934
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Post by tdg8934 » Fri Jan 09, 2009 5:06 am

Wow - Nice display!

Originally this project was an experimentation at an initial design to display a picture (e.g. smiley face) on a 16x16 LED matrix. However, I then wanted to expand on it to add a clock. However, LED color control circuits took 1 too many I/O pins so I had to move to an SX52 (that had 4 extra I/O pins on RA as compared to the SX48). Since I had the I/O, I continued on with an existing project for clock functionality. I was going to stop there but I figured I may want to sell this as a kit or something later and the user may not have an SX-Key to program the time/date in. So adding a 74HC165 with up to 8 pushbuttons seemed like a good idea. However, I actually only needed 3 so, there is just enough I/O for this left on the SX52, so leaving out the 74HC165 could have been done too but since it was already in place in my design and build, I left it in for future push button control expansion.

I could have added the extra hardware to made it a serial LED matrix device but since I already had alot of I/O for the LED matrix, I wanted to initially utilize the 32 pins on the SX48 (which later went into being the SX52) to make the programming with arrays much simpler to program.

BTW - I have ordered a BigAVR 2 from MikroElectronika and their BASIC, so I hope at some point to port this over to an AVR as well as other LED sign designs.

Bigglez
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Post by Bigglez » Fri Jan 09, 2009 4:15 pm

tdg8934 wrote:BTW - I have ordered a BigAVR 2 from MikroElectronika and their BASIC, so I hope at some point to port this over to an AVR as well as other LED sign designs.
This one? Looks interesting. Does it cover the
ATtiny and ATmega chips? There's a lot of
raw horse-power in smaller AVRs (compared
to PICs and PICAXE chips).

No Flames, pleeease! Just my opinion.

tdg8934
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Post by tdg8934 » Sat Jan 10, 2009 8:08 am

We are looking at finding the best and easiest method to interface to large indoor and outdoor signs (single color and RGB video type). SX chips by Parallax may not cut it so we are looking at the ATmega2560 using a BigAVR2 board and also possibly using an Arduino board. I do not have experience with either of these but will soon be learning.

Bigglez
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Post by Bigglez » Sat Jan 10, 2009 9:27 am

tdg8934 wrote: We are looking at finding the best and easiest method to interface to large indoor and outdoor signs (single color and RGB video type).
We? Is this a commercial product?
tdg8934 wrote:we are looking at the ATmega2560 using a BigAVR2 board and also possibly using an Arduino board.
Arduino = Atmega128 (PDIP 28 or TQFP 32) @ $4.08
Atmega2560 = TQFP100 = $16.77
Arduino Pro (5V 16MHz) = $19.95
BigAVR2 = 114 Euro

Commercial LED displays often use the RabbitCore engine = $79 - $99

tdg8934
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Post by tdg8934 » Sat Jan 10, 2009 11:42 am

Thanks for the information about the RabbitCore engine. Seems like there are not many people with good experience in this stuff. I have been focused on Parallax micro-controllers the last 3 years, it's time to break away but not abandon.

As far as "we", I am doing some R/D work for a small company wanting to break into this field.

Bigglez
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Post by Bigglez » Sat Jan 10, 2009 11:56 am

tdg8934 wrote:Seems like there are not many people with good experience in this stuff.
This is not the place to come for enthusiastic help. Although
the server and admin are sponsored by the magazine
publisher don't expect the regular posters here to be in
touch with articles, industry trends, etc.

For PIC support Chuck Hellerbuyck writes/wrote a
column in Nuts and Volts and has more info here.
tdg8934 wrote:I have been focused on Parallax micro-controllers the last 3 years, it's time to break away but not abandon.
The time and energy invested in a particular device family
is important. Microchip knows this and actively supports
hobby and students for later commercial payback.

Parallax has done similar effort. Jon Williams is/was the FAE
for them, and runs a column in Nuts and Volts. He
brings amazing tips and tricks to his articles!

Do an ad page count in the magazines to see who's interested
in 'our' hobby/student business today.

tdg8934
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Post by tdg8934 » Sat Jan 10, 2009 12:08 pm

Thanks for the advice. Jon Williams has been a big help to me with designing the 16x16 clock display for the article. He continues to be a leader in the field and offers his help to readers like me. Thanks again!

sparkplug
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Re: Jan09 - 16x16 Tri-colored LED matrix Real Time Clock

Post by sparkplug » Thu Apr 21, 2011 8:04 am

Hey everybody,

As a novice in electronics i have to admit my first attraction to the field was the usage of LED lights and trying to come up with unique engineering ideas in which to apply their usage. My only experience thus far has been in devices that conduct tests (such as a calcium chloride test), and make measurements. The reason I am posting on this thread is so that those of you who have already posted here may come back and give me a tip or two. I have very little formal training, but have been nitpicking away with little online tutorials etc. Would you all be able to recommend a starting place or test project I can due that may further my knowledge? Thank you.

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