Picture of Dot Matrix Business Card
If my flashlight business card isn't advanced enough for you, then how about one with a full graphical display on it that can be customised for a number of scrolling messages? This one could be made in quantity for about a $5 parts cost, and it is only a little bit more expensive if you are making just a few. I won't kid you that this is an easy design to make - don't try it unless you have very good soldering skills and some experience in electronics. Some of the components here are smaller than grains of rice, so it would be useful to have good eyesight as well! Like the flashlight card, it is more of a proof of concept than something you can churn out in quantity, but it might at least give you an idea of what can be achieved, and where business cards might be in just a few years time.

Step 1: About The Design

Picture of About The Design
This is the sort of card that would suit a high-tech business, or those who were involved in high-value contracts, where an innovative image is all important. I would never suggest that it would replace a conventional business card, but to impress that all-important prospective client, there would be more than a few companies who would be happy to spend just an extra few dollars. Like the flashlight card, the aim is to design a business card that people just can't throw away!

The design is really quite simple for what it does - a matrix of 5x15 LEDs, connected to a single-chip "PIC"microcontroller. A handful of resistors and switches complete the design (Schematic available below). By keeping the microcontroller in sleep mode unless the buttons are pressed, the battery can last several years, and still allow a couple of thousand displays of your messages.
MatrixSchematic.pdf(595x842) 101 KB
1-40 of 157Next »
yaly2 months ago
You can also use jumper resistors or "000" value smd resistors to connect the horizontal lines and have some traces running under the LEDs.
KellyKandy3 months ago

Great idea

i want to make this, but i don't want to use surface mount, i.e. normal LEDs, batteries. so what components should i use. please help :(
Fayez slim2 years ago
yes i know i check but the battery holder in the double sided pcb
tomward (author)  Fayez slim2 years ago
Hi - the one in step 2 is 18-3780 from rapidonline.com. The one referred to in step 7 was just a couple of bits of wire soldered in - it wasn't a proper battery holder.
Fayez slim2 years ago
plz upload a photo of it or his name to buy it plz
Fayez slim2 years ago
and sorry for my question but i have another one what is this type of battery holder in the new pcb
tomward (author)  Fayez slim2 years ago
Hi - if you check step 2 of the instructable it lists the parts and suppliers
Fayez slim2 years ago
if i want to write my name and my email plz tell me how
my name is fayez slim
and my email is fayezslim@hotmail.com
plz reply
tomward (author)  Fayez slim2 years ago
Hi - if you check step 5 of the instructable it will tell you how to spell out messages
Fayezslim2 years ago
can i use your hex file in matrixcode.zip with out editing it plz reply
tomward (author)  Fayezslim2 years ago
You are welcome to but it won't be much use for you as it will have my name and email on it rather than yours!
india57853 years ago
I am looking to build the same circuit but modify the program. I have run into a road block trying to get a PCB manufactured. My education hasn't covered creating Gerber files and such... Is the PCB simply 2 layers?
tomward (author)  india57853 years ago
It is actually only 1 layer - very simple. Best bet to do it commercially is to find someone who accepts an Eagle ".brd" file which is attached to the instructables
DUDE !!!

Seriously awesome stuff ! Many thanks for showing exactly how this is made with VERY - Clear & concise pictures and steps!

Also interested in your MK 2 version with colour OLED screen!

Undoubtedly Awesome & is every possible meaning of my words!

You're A Genius! Simply-Said !
nerd74733 years ago
where did you get the parts?
check out step 2
farzadbayan3 years ago
Very interesting!
CHANNIHONEY3 years ago
channihoney says:
how can write new message this display ?
I've made a few of these already, they have been working great :) I've also recently started working on a completely flush version, which will hopefully be just as thick as the pcb... All the components are sunk in, except for the LEDs! Thank you so much for this amazing Instructable, you've given me hours of trial and error and most of all a chance to learn about smd soldering and programming :)
aessam13 years ago
i really like it
it's very well designed
and i really like the idea for the overlay
very nice....
good job pal
got an idea tom to revise the board. Where the Battery is placed cut out a hole and place the battery in the hole, and use tin flaps soldered to the board. That will make it thinner.
yakteeno4 years ago
How can I make one of these
mangomango4 years ago
im really interested in making this into a portable sound analyzer. like a SpeaQualiser. anyway, i was wondering just how durable this is and size comparisons. like would i be able to keep this in my wallet?
volkee4 years ago
May i make this commercially in Thailand?
Just using the idea, not the whole thing.
tomward (author)  volkee4 years ago
Sure - the information is freely available so go for it. Send us an image of what you come up with if you get one up and running - would be interested to see.

shaf7895 years ago
i dont no how to re name?
It's not becouse you make It in a Mac? I use only Windows, i never tried Mac. Anyway I opened It with Notepad of Windows and It says this (a little part): €B | < ÎëH§(ƒ x ™ G©Í ü>€ÂFˆÊ ü>€ÂFˆÊ ü>€ÂFˆÊ ÿ š™™™™™©?š™™™™™™? Top Bottom Pads Vias Unrouted Dimension tPlace bPlace tOrigins bOrigins tNames bNames tValues bValues tStop bStop tCream bCream !" tFinish "! bFinish #$ tGlue $# bGlue %& tTest &% bTest '( tKeepout (' bKeepout )* tRestrict *) bRestrict ++ vRestrict ,, Drills -- Holes .. Milling // Measures 00 Document 11 Reference 22 dxf 34 tDocu 43 bDocu 56 tGND_GNDA 65 bGND_GNDA 87 wert [[ Nets \\ Busses ]] Pins ^^ Symbols __ Names `` Values aa Info bb Guide d Muster ee Patch_Top ff Vscore hh Name tt Patch_BOT yy _tsilk zz _bsilk —— HeatSink ÈÈ 200bmp ÉÉ 201bmp ÊÊ 202bmp úú Descript ûû SMDround þþ cooling P - ««‡ ¸ ó € \ Lightbox E þÿsë ÐqfSO28W +€ &ïþÿPLÿÿ¸ø* 2 +€ Ú PLÿÿ¸ø* 13 +€ Š½þÿPLÿÿ¸ø* 1 +€  ÿÿPLÿÿ¸ø* 3 +€ ^RÿÿPLÿÿ¸ø* 4 +€ vB PLÿÿ¸ø* 14 +€ >ß PLÿÿ¸ø* 12 +€ ¢­ PLÿÿ¸ø* 11 "€ '‘þÿxæ þn xæ ç "€ 'þn ˆÿÿ‘þÿˆÿÿç "€ '‘þÿˆÿÿ‘þÿxæ ç "€ 3„a xoÿÿ|žþÿxoÿÿø "€ 3|žþÿxoÿÿ|žþÿ ƒÿÿø "€ 3|žþÿ ƒÿÿ|žþÿˆ ø "€ 3|žþÿˆ „a ˆ ø "€ 3„a ƒÿÿ|žþÿ ƒÿÿø 1€Š½þÿœ1 Î >NAME +€ –µÿÿPLÿÿ¸ø* 6 +€ jJ PLÿÿ¸ø* 9 +€ úƒÿÿPLÿÿ¸ø* 5 +€ 2çÿÿPLÿÿ¸ø* 7 +€ | PLÿÿ¸ø* 10 +€ Î PLÿÿ¸ø* 8 "€ 3„a ˆ „a ƒÿÿø "€ 3„a ƒÿÿ„a xoÿÿø 1€Š½þÿÈœÿÿÎ >VALUE"€ 'þn xæ þn ˆÿÿç +€ vB °³ ¸ø* 15 +€ Ú °³ ¸ø* 16 +€ >ß °³ ¸ø* 17 +€ ¢­ °³ ¸ø* 18 +€ | °³ ¸ø* 19 +€ jJ °³ ¸ø* 20 &€ 3÷³þÿ00ÿÿÇþÿkÿÿ &€ 3“åþÿ00ÿÿ¹øþÿkÿÿ &€ 3/ÿÿ00ÿÿU*ÿÿkÿÿ &€ 3ËHÿÿ00ÿÿñ[ÿÿkÿÿ &€ 3gzÿÿ00ÿÿÿÿkÿÿ &€ 3¬ÿÿ00ÿÿ)¿ÿÿkÿÿ &€ 3ŸÝÿÿ00ÿÿÅðÿÿkÿÿ &€ 3; 00ÿÿa" kÿÿ &€ 3×@ 00ÿÿýS kÿÿ &€ 3sr 00ÿÿ™… kÿÿ &€ 3¤ 00ÿÿ5· kÿÿ &€ 3«Õ 00ÿÿÑè kÿÿ &€ 3G 00ÿÿm kÿÿ &€ 3ã8 00ÿÿ L kÿÿ &€ 3ã8 q” L ÐÏ &€ 3G q” m ÐÏ &€ 3«Õ q” Ñè ÐÏ &€ 3¤ q” 5· ÐÏ &€ 3sr q” ™… ÐÏ &€ 3×@ q” ýS ÐÏ +€ Î °³ ¸ø* 21 +€ 2çÿÿ°³ ¸ø* 22 +€ –µÿÿ°³ ¸ø* 23 +€ úƒÿÿ°³ ¸ø* 24 &€ 3; q” a" ÐÏ &€ 3ŸÝÿÿq” ÅðÿÿÐÏ &€ 3¬ÿÿq” )¿ÿÿÐÏ &€ 3gzÿÿq” ÿÿÐÏ +€ ^Rÿÿ°³ ¸ø* 25 +€  ÿÿ°³ ¸ø* 26 +€ &ïþÿ°³ ¸ø* 27 +€ Š½þÿ°³ ¸ø* 28 &€ 3ËHÿÿq” ñ[ÿÿÐÏ &€ 3/ÿÿq” U*ÿÿÐÏ &€ 3“åþÿq” ¹øþÿÐÏ &€ 3÷³þÿq” ÇþÿÐÏ Üÿÿ$ õ rf +€2 pÆ Ä°' P$1 +€2 8c ÄÄ P$2 +€2 ÄÄ P$3 +€2 ÈœÿÿÄÄ P$4 +€2 9ÿÿÄÄ P$5 4ÿšÿÌ f #rf "€3Èœÿÿ8c 8c 8c { "€18c 8c 8c Èœÿÿ{ "€08c ÈœÿÿÈœÿÿÈœÿÿ{ "€2ÈœÿÿÈœÿÿÈœÿÿ8c { +€ ,kÿÿˆ; œ1Î P$1 +€ ,kÿÿxÄÿÿœ1Î P$3 +€ Ô” ˆ; œ1Î P$2 +€ Ô” xÄÿÿœ1Î P$4 mþmþ““ 2rf %€ 3 ö ö { *€ Š½þÿŠ½þÿˆ POS1 *€ vB vB ˆ POS2 *€ Š½þÿvB ˆ NEG1 *€ vB Š½þÿˆ NEG2 (€ ø* € led íÿÏÿ 1 Lrf?rf +€ L    C +€ ´âÿÿ   A &€ 3lîÿÿ” ” 4! &€ 3lîÿÿÌÞÿÿ” lîÿÿ "€ 3`ðÿÿ” `ðÿÿlîÿÿü "€ 3  ”   lîÿÿü &€ lîÿÿ Hôÿÿ¸ &€ ¸ ” ¸ &€ $úÿÿ Ü ¸ 1€2çÿÿ2çÿÿÎ >NAME And I can't change the name, in properties and when I download It, says: Downloading FJ57QXVFT3K2QPS.tmp... Did you tried to download It in your PC? It's really strange. Now I use Windows 7
tomward (author)  Gonzalo Ruiz5 years ago
After renaming, you will need Eagle PCB (Free download) to view and edit the PCB file.
Hi in the step 8, the download link is naemd 'Led Card.brd' and when I download It it´s named 'FJ57QXVFT3K2QPS.tmp'. Why It´s different?Why the format is '.tmp' in stead of '.brd'? Please help me.
tomward (author)  Gonzalo Ruiz5 years ago
Strange - didn't use to do this - tried uploading again and same thing happened. You will need to rename the ".TMP" file to ".BRD" after you have downloaded it - google "Change File Extension" if you need to know how to do this. This is a newer version of the PCB file - a double-sided one with no need to use the "mock double sided board" trick with the sticky tape. Apologies, but no longer have the original board.
samr37l5 years ago
 Where did you find the library for the led's? I can't seem to find the library....
tomward (author)  samr37l5 years ago
There is no library needed - all code is in one file attached to the instructable.
samr37l tomward5 years ago
 Yah, but I would like to design my own. (Yours is just WAY to complicated for me, but it is REALLY cool)
satadru5 years ago
hi...i jst gng to start wth pic mic.can u tell me which book is good to guide me properly with pic microcontroller........
tomward (author)  satadru5 years ago
Sorry, but don't have any books on PICs - just done a search on "PIC Microcontrollers" on Amazon and their looks like to be a good few for beginners with good reviews - perhaps someone else can recommend one?
glocketz6 years ago
Hey, Sunstone circuits (custom pcb manufacturer) requires the matrix to be in either a .RAR, .123, . BRD, or .BIN formats. Can you please upload a copy of the matrix in one of those formats so I can have a circuit printed? Thanks.
1-40 of 157Next »