ps/2/you: go-anywhere, led digital message board - led message board

Material: frame wood (A): 4' of 1x4 (
Nominal size)
Or a board of similar size, or twice the stockEight wood screw with a length of 3/4 "x 1 5/8 (B)
: 8, 1 long "longThree 8x32 point matrix LED display from Sure Electronics (C). $12. 90 ea.
The power Jack matching the adapter (E).
This is a standard 2.
Sparkfun offers 1mm sheets for $1. 25 (on-off-on)power switch (D).
Digikey parts: 450-1527-
NDPS/2 port on the old computer motherboard (F)(
Ask the local computer store and they may give you a failed motherboard for free).
1/8 or 1/4 of 21 "x4" Lexan or plexiglass (G)(
Try your local car glass shop).
I use this to make a clear back for the frame so you can still see what's going on inside.
Wood paneling or plastic is also OK.
2 AA battery brackets (I)
AA battery stand in a long and flat configuration (H)
A few feet of 22 ad hoc working groups (J).
Flexible bread board jumper (K). $6.
At Solarbotics 00: solid 22 ad hoc workgroup wires can be used for this purpose, but the purpose is-
Built-in breadboard jumpers are more flexible and easier to use-well worth the cost.
Electrical tape or heat shrink tube (L). Mini self-
Adhesive bread board (M): $3.
$95 for Sparkfun: or $4.
00 in MakerShed: micro controller (N)
From MakerShed ($9. 95)
Or Solarbotics ($9. 99)
Ardweeny is an Arduino.
Compatible micro controller with small footprint-
Only the size of the Atmega chip itself. This (
And the same small cost)
This is a great choice for breadboards
Basic projects suitable for small places are needed.
Unlike Arduino, an external USB/serial programming adapter is required for Ardweenies.
However, they are also cheap: $15 for MakerShed ()or Sparkfun ()5v regulator (O).
The 7805 series of regulators are cheap and adequate ($0.
29 from MakerShed: but a low-voltage drop model like the lm2937 will give you more running time on the battery, especially if you're using low power
Voltage NiMH AAs ($1.
50 in Solarbotics: μ f (104)
Ceramic Capacitors (P)
10 μF electrolytic capacitor (Q)
Six small cap screws (R)(
For holding on the back cover)
9-12 v AC/DC adapter (S).
The best place I found was the Salvation Army thrift store.
They usually have a lot of options at about $1 per piece.
If you don't have a thrift store on hand, there's one for $5. In Sparkfun 95 (or $6.
Month in MakerShed (
Computer keyboard PS/2 (T)
, Or a USB keyboard with a PS/2 adapter.
In order to reduce trouble and time investment, a kit containing the collected materials for the construction of this project can be purchased at the manufacturer's shed shop: Saw or chop saw (optional)
The serial programming of chiselmeasurement tapeDrill and bitsScrewdriverSoldering iron solderPliers and cuttersGlue gunFTDI (
Sparkfun is available for $14. 95 --
Is a few ways to make the framework.
I have a lumber shop so I made some extra stuff
Deep frame with beveled and slot cut on long side to accommodate display panel.
The shape and style of the frame doesn't matter, so make your creativity (and materials)
Have a say in design.
Cut 1x4 in half vertically and make about 3/4 "x 1 3/4" strips (
A typical "1x4" is actually about 3/4x3 1/2).
Use a chop saw or a hand saw to cut a 45 ° angle at one end of each piece, oriented so that the cut can cross the narrow surface of the plate diagonally.
Measure 18 1/4 "from the inside of the angle cut, and then cut 45 ° angle.
Both cuts should be tilted outward from the measured length.
Repeat on the second board.
This will be the two long sides of the frame.
On a flat surface, two boards are arranged side by side with narrow edges.
Place a display panel face down between the plates, so that the flanges on the panel lean against the plate, and there is a prominent LED matrix between them.
Make sure the circuit board is close to the side of the LED matrix.
Measure between the outer edges of the plate.
This will be the length of the end part of the frame.
Mark the distance you measure above, starting with the long end of the oblique cut on the remaining plates.
In this case, both mitres should start with the measured length, which will be the longest size of each piece.
Cut one of these.
Mark the other one, but don't cut it yet.
Arrange your DC Jack, PS/2 port, and power switch to the edge of the uncut part you just marked.
Mark a gap at the edge of the plate, which is large enough to make them adjacent to each other.
Cut two edges of the gap with a chop saw or a hand saw.
Do a few cuts in the middle of the gap to the right depth, then cut out the rest of the wood, smooth the bottom of the gap.
Try installing the port and switching to the groove.
They should slip in easily, but there is no extra space.
Follow the mark in step 3 to cut the second notch end piece.
Set the blade depth of the table saw to 5/16 "(
Display the dimensions of the flange on the panel).
Cut a notch vertically from the inside of each long frame sheet, inches from the edge.
Use a narrow cut blade if possible.
This cut should match the flange on the display panel so that the panel slides into the slot and is roughly flush with the front of the frame.
Slide all three display panels to the slot to make sure they all have the same sides (
Check the text on the back of the panel to confirm this).
Install the end of the frame and fix the frame piece in the appropriate position to drill the guide hole and reverse sink for the screws that fix the frame together.
When you go, it might help to put the screws in and keep the frame together.
Make sure your counter sink is deep enough not to over tighten the screws to avoid the fragmentation of the frame pieces.
Add some glue to the gap end of the frame to get extra strength if you want, but if you want to get the display panel out, please don't stick the other end.
The frame is done now!
Note: If you are unable to access the store and/or table saw, frames can be made in other ways.
One method is as follows.
Cut two 1x2 plates (
Really 1/2x3/4)
To 18 1/4 "and 2 short length 1x2 are installed on both ends.
Then, slotting, display the flange, before use
Drill holes on the flanges and screw them to the front of the frame.
Place the assembled frame on top of the plexiglass or Lexan sheet.
Using screws or other raw objects, draw a mark around the edge of the frame.
Cut the backing with a hand saw, a table saw or a cutting tool of your choice.
Arrange the cutting pieces on the back of the frame and drill six pilot holes through the back of the padded material and the frame itself.
Once all the electronics are in place and work properly, it is ready to be turned off now.
By welding the positive lead of one battery pack to the negative lead of the other battery pack, two battery packs are connected in series.
The power switch and the DC Jack will connect the remaining two leads.
Lengthen the remaining wires if necessary so that they can arrive from where the battery pack is located (
I put them far away from the port)
The gap to which the Jack and switch will arrive.
Tape or heat shrink at the connection.
Cut off the end of one of your black breadboard jumpers and peel off and tin on the wires.
Do the same with the red jumper.
Welding a bare end-
End the black breadboard jumper and the black wire from the battery pack to the negative end of the DC power jack.
Weld a short red line between the positive end of the DC Jack and an external contact on the switch.
Connect the red-
Switch the common end bread board jumper, the battery positive pole of the third switch terminal.
If everything goes well, you should have a power off position with a switch in the middle, a battery power position on one side and an adapter power supply on the other.
Cut off one end of the four breadboard jumpers--
One red, one black, one blue and one white (
Or your similar product).
Weld them to the positive, negative, data, and read and write pins on the PS/2 port (see diagram).
Dry install the PS/2 port, DC Jack and power switch again into the groove at the end of the frame.
Heat the glue gun, before quickly pushing the glue gun tightly into the gap, apply a little glue on each glue gun.
This is a recognized non-Orthodox way of connecting, usually a PCB or a panel-
Installed components, but it has the advantage of being very strong and relatively neat-a good alternative when there is no PCB or mounting panel nearby.
Use the two ribbon cables that come with the LED panel to connect the adjacent ports on the three panels to each other.
Plug one end of the third cable into the port closest to the switch and power jack.
Fold this ribbon tightly and attach the free end to the inside of the frame with hot glue.
The plug should be oriented towards the back of the frame, there is enough space to insert it between it and the back cover of the breadboard jumper, and there is enough space between it and the next port to accommodate the breadboard.
There is a small DIP switch block marked CS1, CS2, CS3 and cs4 on the back of each display panel.
These switches control how the micro-controller identifies each display panel.
Because the reference point of our code is the left side of the display (
From the front of the display)
, We need to identify the panels as 1, 2 and 3 from left to right.
Turn off all switches on the leftmost panel except switch 1, except for Switch 2 on the middle panel, and all switches except switch 3 on the right panel. (
To see how these switches work, try setting them to other order after running the display; )
Plug your Ardweeny and voltage regulator into the breadboard and make sure that Ardweeny runs all the way to one end and the voltage regulator runs all the way to the other end to prevent any pins from overlapping. Insert the 0.
1 uF capacitor between voltage regulator input and ground leg.
Put the positive leg of the 10 uF capacitor into the output bus of the regulator, and the negative leg into the ground bus.
Now peel off the backing of the bread board (very exciting)
Stick it on a flat surface
Install the Holtek chip on the back of the display panel closest to the power switch and IO port.
Check the data sheet of the voltage regulator to determine which pin is input, which pin is grounded, and which pin is output (
Usually, the sequence is-GND-
See the front of the regulator from left to right, but make sure to check the data sheet).
Since the ground bus of the regulator may now be a bit full, use a small breadboard jumper to connect it to the unused bus on the other side of the breadboard.
Plug the power cord of the switch common power supply into the input bus of the regulator and plug the GND line of the DC jack into the new ground bus.
Use two more jumpers (red and black)
Connect the output and common negative poles of the voltage regulator to the bus connected to the V and GND pins of Ardweeny.
Plug the power cord of the PS/2 port into the power output of the regulator, or plug the power supply of Ardweeny and the GND of the port into the second GND bus, or the GND bus of Ardweeny
Insert the data cable of PS/2 port into pin D3 on Arwdeeny and the read/write line into pin d7 of Arwdeeny.
Go out a few more bread board jumpers.
CS2, showing the first line on the ribbon (marked in pink)
, Go to the d3 pin on Ardweeny, and the second wire CS 3 go to the d3 pin on Ardweeny.
Line 3 (CS 1)goes to D4.
Next, we read/write and data on pin 5 and pin 7 of the display ribbon.
Read/Write to pin D11 on Ardweeny and the data is sent to pin D10.
The last two pins on the display connector are GND and power.
15 is GND and 16 is 5 v.
You can put them on the output and GND of the voltage regulator, or on the power supply that goes into Ardweeny.
If this looks confusing, check out the schematic and pin connection diagrams that come with this step.
Download the attached zip file.
Decompress it and move the PS2Keyboard and MatrixDisplay folders to the Arduino library directory.
This code is compatible with Arduino IDE 1.
0 so if you have the old version, please update it before programming the signature.
Open the code in the Arduino IDE, connect the computer to Ardweeny using the FTDI programming adapter, and upload the sketch.
If everything goes well, the default text will be displayed later.
Unplug the programmer and load some batteries into the battery pack (
If you want to use battery power)
, Then screw to the back cover. You're all set!
Ardweeny's code is based on two open source Arduino libraries: PS2Keyboard (
MatrixDisplay was originally a thread on the Arduino Forum and is now hosted in the code, which uses the interrupt routine to read the original scan code from the keyboard and buffer them, and then before sending the pixels, find the appropriate characters in the font glyph array-
Display specific commands for the panel.
Further lighting has a lot of room for improvement in the code.
An obvious addition is to use the CTRL key and other key pen drawings to modify how the lines of text are displayed-flashing, sliding in from the top, fading in, or other fascinating effects.
Up to 4 display panels can be cascade together, and of course Electronics recently released an 8x32 panel using 5mm instead of 3mm LEDs, so the oversized PS/2 you show may also be a cool change.
Scrolling the font displayed by your own font is included in an array of large hexadecimal values in the font. h file.
It's not friendly to editors, but Brent Morse of Morse-Code.
Com made a small free app that you can use to design your own 5x7 LED display glyphs (
In addition to modifying the font, you can also make a custom smile or any other pattern you want using the font app.