Combine three inexpensive LED matrix display panels, an Ardweeny microcontroller and a standard PS/2 computer keyboard into your own go-anywhere, instantly updatable 768-pixel digital message board.
The code can hold up to six lines of text with a maximum of 100 characters each. Pressing a key on the keyboard gets you to input mode. Use the up and down arrow keys to select which line to edit. ENTER puts the system back into output mode. When in output mode, each line of text will display for 1 second (you can set this in the sketch), or if the line is longer than 16 characters, it will scroll across the display before moving onto the next line.
Send some text messages:
The uses for this contraption are many. Plug the keyboard in and enjoy putting your wittiest “wiseclacks” on it in the safety of your home, shop, or office, or use the battery option to take it into the wide world. We like to leave the keyboard accessible so that passers by can add a riposte or two to the dialogue, but if monologue is more your thing you can always take it elsewhere. Here's another idea: drill a broomstick-sized hole in the bottom of the frame and add a removable handle so you can wander the streets digitally promoting your geekified political leanings. Score keeping at sports events, birthday greetings, advertising your wares at a farmers market, beaming cryptic messages to your neighbours across the street – the possibilities are endless!
The code can hold up to six lines of text with a maximum of 100 characters each. Pressing a key on the keyboard gets you to input mode. Use the up and down arrow keys to select which line to edit. ENTER puts the system back into output mode. When in output mode, each line of text will display for 1 second (you can set this in the sketch), or if the line is longer than 16 characters, it will scroll across the display before moving onto the next line.
Send some text messages:
The uses for this contraption are many. Plug the keyboard in and enjoy putting your wittiest “wiseclacks” on it in the safety of your home, shop, or office, or use the battery option to take it into the wide world. We like to leave the keyboard accessible so that passers by can add a riposte or two to the dialogue, but if monologue is more your thing you can always take it elsewhere. Here's another idea: drill a broomstick-sized hole in the bottom of the frame and add a removable handle so you can wander the streets digitally promoting your geekified political leanings. Score keeping at sports events, birthday greetings, advertising your wares at a farmers market, beaming cryptic messages to your neighbours across the street – the possibilities are endless!
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Signing UpStep 1: Materials and tools
Materials:
Frame wood (A): 4' of 1x4 (nominal dimensions) or similar sized board, or double that length of 3/4” x 1 5/8” stock
Eight wood screws (B): #8, 1 ¼” long
Three 8x32 dot matrix LED displays from Sure Electronics (C). $12.90 ea. http://www.sureelectronics.net/goods.php?id=1118
DC power jack to match your adapter (E). Here is a standard 2.1mm one from Sparkfun for $1.25 http://www.sparkfun.com/products/119
SPDT (on-off-on) power switch (D). Digikey part#: 450-1527-ND
PS/2 port from an old computer motherboard (F) (ask a local computer shop and they will likely give you a defunct motherboard for free).
A 21” x 4” piece of 1/8” or 1/4” Lexan or Plexiglass (G) (try your local auto glass shop). I used this to make a clear back for the frame, so that you could still see the stuff going on inside. Wood paneling or plastic would work too.
2 AA battery holder (I) http://www.sparkfun.com/products/551
4 AA battery holder in a long, flat configuration (H) http://www.sparkfun.com/products/9547
A few feet of 22 AWG stranded wire (J).
Flexible breadboard jumpers (K). $6.00 at Solarbotics: http://www.solarbotics.com/products/21035/
You can use solid 22 AWG wire for this, but purpose-built breadboard jumpers are more flexible and much easier to use – well worth the expense.
Electrical tape or heat shrink tubing (L).
Mini self-adhesive breadboard (M): $3.95 at Sparkfun: http://www.sparkfun.com/products/8802 or $4.00 at MakerShed: http://www.makershed.com/ProductDetails.asp?ProductCode=MKKN1
Ardweeny microcontroller (N), from MakerShed ($9.95) http://www.makershed.com/ProductDetails.asp?ProductCode=MKSB012 or Solarbotics ($9.99) http://www.solarbotics.com/products/kardw/
The Ardweeny is an Arduino-compatible microcontroller with a tiny footprint -- just the size of the Atmega chip itself. This (and its equally diminutive cost) make it a great choice for breadboard-based projects that need to fit into small places. Unlike the Arduino, Ardweenies requires an external USB/serial programming adapter. They're pretty cheap too though: $15 from MakerShed ( http://www.makershed.com/FTDI_Friend_v1_0_p/mkad22.htm ) or Sparkfun ( http://www.sparkfun.com/products/9716 )
5v regulator (O). 7805 series regulators are cheap and plentiful ($0.29 from MakerShed: http://www.makershed.com/ProductDetails.asp?ProductCode=JM51263) but a low dropout model like the lm2937 will give you more run time on batteries, especially if you're using lower-voltage NiMH AAs ($1.50 at Solarbotics: http://www.solarbotics.com/products/lm2937/)
0.1 μF (104) ceramic capacitor (P)
10 μF electrolytic capacitor (Q)
Six small pan head screws (R) (for holding on the back cover)
9 – 12v AC/DC adaptor (S). The best place I've found to get adaptors is a Salvation Army thrift store. They usually have a large selection for about $1 a piece. If you haven't got a thrift store handy, there's one for $5.95 at Sparkfun (http://www.sparkfun.com/products/298) or $6.50 at MakerShed (http://www.makershed.com/ProductDetails.asp?ProductCode=MKSF3)
Standard PS/2 computer keyboard (T), or USB keyboard with PS/2 adapter.
For reduced hassle and time input, a kit containing the collected materials to build this project can be purchased at the Maker Shed Store: http://www.makershed.com/PS_2_You_Parts_Kit_p/msps2u.htm
Tools:
Hand saw or chop saw
Table saw (optional)
Chisel
Measuring tape
Drill and bits
Screwdriver
Soldering iron and solder
Pliers and cutters
Glue gun
FTDI serial programmer (available from sparkfun for $14.95 -- http://www.sparkfun.com/products/9716)
Frame wood (A): 4' of 1x4 (nominal dimensions) or similar sized board, or double that length of 3/4” x 1 5/8” stock
Eight wood screws (B): #8, 1 ¼” long
Three 8x32 dot matrix LED displays from Sure Electronics (C). $12.90 ea. http://www.sureelectronics.net/goods.php?id=1118
DC power jack to match your adapter (E). Here is a standard 2.1mm one from Sparkfun for $1.25 http://www.sparkfun.com/products/119
SPDT (on-off-on) power switch (D). Digikey part#: 450-1527-ND
PS/2 port from an old computer motherboard (F) (ask a local computer shop and they will likely give you a defunct motherboard for free).
A 21” x 4” piece of 1/8” or 1/4” Lexan or Plexiglass (G) (try your local auto glass shop). I used this to make a clear back for the frame, so that you could still see the stuff going on inside. Wood paneling or plastic would work too.
2 AA battery holder (I) http://www.sparkfun.com/products/551
4 AA battery holder in a long, flat configuration (H) http://www.sparkfun.com/products/9547
A few feet of 22 AWG stranded wire (J).
Flexible breadboard jumpers (K). $6.00 at Solarbotics: http://www.solarbotics.com/products/21035/
You can use solid 22 AWG wire for this, but purpose-built breadboard jumpers are more flexible and much easier to use – well worth the expense.
Electrical tape or heat shrink tubing (L).
Mini self-adhesive breadboard (M): $3.95 at Sparkfun: http://www.sparkfun.com/products/8802 or $4.00 at MakerShed: http://www.makershed.com/ProductDetails.asp?ProductCode=MKKN1
Ardweeny microcontroller (N), from MakerShed ($9.95) http://www.makershed.com/ProductDetails.asp?ProductCode=MKSB012 or Solarbotics ($9.99) http://www.solarbotics.com/products/kardw/
The Ardweeny is an Arduino-compatible microcontroller with a tiny footprint -- just the size of the Atmega chip itself. This (and its equally diminutive cost) make it a great choice for breadboard-based projects that need to fit into small places. Unlike the Arduino, Ardweenies requires an external USB/serial programming adapter. They're pretty cheap too though: $15 from MakerShed ( http://www.makershed.com/FTDI_Friend_v1_0_p/mkad22.htm ) or Sparkfun ( http://www.sparkfun.com/products/9716 )
5v regulator (O). 7805 series regulators are cheap and plentiful ($0.29 from MakerShed: http://www.makershed.com/ProductDetails.asp?ProductCode=JM51263) but a low dropout model like the lm2937 will give you more run time on batteries, especially if you're using lower-voltage NiMH AAs ($1.50 at Solarbotics: http://www.solarbotics.com/products/lm2937/)
0.1 μF (104) ceramic capacitor (P)
10 μF electrolytic capacitor (Q)
Six small pan head screws (R) (for holding on the back cover)
9 – 12v AC/DC adaptor (S). The best place I've found to get adaptors is a Salvation Army thrift store. They usually have a large selection for about $1 a piece. If you haven't got a thrift store handy, there's one for $5.95 at Sparkfun (http://www.sparkfun.com/products/298) or $6.50 at MakerShed (http://www.makershed.com/ProductDetails.asp?ProductCode=MKSF3)
Standard PS/2 computer keyboard (T), or USB keyboard with PS/2 adapter.
For reduced hassle and time input, a kit containing the collected materials to build this project can be purchased at the Maker Shed Store: http://www.makershed.com/PS_2_You_Parts_Kit_p/msps2u.htm
Tools:
Hand saw or chop saw
Table saw (optional)
Chisel
Measuring tape
Drill and bits
Screwdriver
Soldering iron and solder
Pliers and cutters
Glue gun
FTDI serial programmer (available from sparkfun for $14.95 -- http://www.sparkfun.com/products/9716)
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just a few things: I am in the middle of making this and my ardweeno lights up, but the LED's aren't. I have undid the wires 10 times and re-wired them. It had originally lit up, but it was not moving, it just said HELLO HELLO HELLO. Now it is not lighting up at all. I hope you can help, thank you!!!
By the way, does your brother have code for a version of this that will accept SMS messages from a GSM/GPRS modem? That would be a Great followup project.
Do you have a scrolling version?
What do you mean by a scrolling version?
can u help me, how if i use standard led dot matrix 8x8 with 74hc595 shift register??
can u send me the schematics and code to my email parjok21@gmailcom ?
thanks
*sorry i'm an amateur in english
http://www.sureelectronics.net/gallery.php?id=1137&img=6076
Greetz from the Netherlands :)
Mark
Sorry for the slow response. I asked my brother who did the code for this project and he said those boards probably wouldn't work without modification to the code. Are you having trouble finding the other ones? Good luck, E
Thanks for that!
But i'd like to use it as a time/temp meter.
Do you maby have a code that displays that?
Thanks!
Thanks, I'll tell you
Great project!
i'm really impressed i must confess. good work once again
please email me at maclee4real@yahoo.co.uk if there is a way to build a microcontroller
thanks
Can one somehow integrate this with an ethernet-shield and send messages over internet to it? Fex via Txitter etc.?
That shouldnt be to difficult, should it?
Thanks for your interest in the project and all the questions!
First one first: it should be fairly easy to modify the code so that it stores the messages until the next time the system is turned on. This would be nice, and is something we have talked about doing. I can let you know if we get it into the main code.
As for the other two questions, they also should be do-able. I'll ask my brother who did most of the code for me about them and we'll see what we can do. It would be good to do an update for the system and these would be fun things to include.
Cheers and thanks -- glad you are having fun with the project.
Is it possible to somehow make it display scandinavian characters? Like these ones: http://www.fiskeklubben.org/charcters/how-to.html
Mabye by replacing the bytes from those input on the keyboard with those letters?
Thanks alot!
Thanks alot for a great tutorial!!! :)
I have my version up and running now, and I enjoy it.
I was wondering about one little thing:
Is it possible to somehow make it not reset when one removes power to the Ardweeny?
Best regards
-maceide
Cap lock light of KB can be ON/OFF, but no display on matrix. Would you please teach me how to build up? Is it required to amend the program? Thanks a lot!
i have arduino uno, can i use it to practice your project?so, please send me a schema to muhammadfaisal82@yahoo.com
thanks a lot
can you post microprocessor and PCB to Sri Lanka..?
thank you.
please reply me.
sanjeawa1978@gmail.com
please don't stop make anator one
ขายส่ง LED
Basically, whatever LED board I have set as #1 doesn't show any data, however 2 and 3 work just fine. I can change the position of 2,3 around, or even double them, however I cannot get #1 to work.
I tried reuploading the code several times, however this seems to have no effect.
I don't think any of the LED units are bad, since all of them work on the 2 or 3 position setting.
Any ideas?
I would suspect the problem might be with the CS1 wire from your Ardweeny to the display ribbon. I have just updated the documentation on that step of the wiring because it has always been a bit confusing. There is now a modified schematic which is much easier to see and it shows the CS number along with the display ribbon number and Ardweeny pin. CS1 is is the third wire on the ribbon cable and it should go into D4 on the Ardweeny. Let me know how this works out.
Just wondering if you have wired the voltage supply wires (red and black) that come with the 8x32 dot matrix displays from Sure?
It seems to work without them (I suppose the ribbon cables supply enough current). They must be optional if you want to use a separate power supply.
Ill be using mine to display information in my Home theater regarding "movies playing" and such.
an answer would be most appreciated.
Your new follower,
Rtty21
:)
Thanks for your enthusiasm and interest in the project! That's correct -- it doesn't light all the LEDs at once. Each of the display panels comes with an Holtek HT1632c driver chip on it. The drivers light one row of LEDs at a time in quick succession, for an overall frame rate of about 100 hz. Fortunately, this is all taken care of by the driver. Our controller just has to tell the driver over a serial connection what pixels to light up and it takes care of the rest.