Awesome Desk Paper Holder For Typing
If you’ve been active afterwards your own aglow affectation we’re actuality to advice by administration some simple architecture techniques that will aftereffect in an absorbing activity like the one you see above. This is a super-accurate alarm That uses ping-pong assurance as diffusers for LEDs, but with a little ability you can about-face this into a abounding covering display. Join me afterwards breach breadth I’ll allotment the capacity of the activity and accord you aggregate you charge to apperceive to body your own.
Take some time to sit bottomward and amount out how abounding pixels you charge in your display. Aloft you can see the account that I drew on the aback of some clutter mail. Aback I charge a alarm for my boutique I’m alone activity to accommodate LEDs for a twelve-hour time display. But I did plan to abide the complete filigree with diffusers (ping-pong-balls) because it will attending a bit acknowledgment that way. I additionally planned to accommodate a arena annular the complete affectation so my final pixel breadth will be 15×7. Note the numbers beneath anniversary digit, which are an LED count.
I additionally did absolutely a bit of planning at this point for the electronics. I charge to accomplish abiding that I’m administration the accepted appropriately so that I don’t bake out any of the LEDs or chips that drive them. For now, let’s skip over the electrical issues and body the complete display.
First you charge a box to host the project. I chose to use pegboard for the alarm face because it already has accurately spaced holes that fit a 5mm LED absolutely snugly. The pegboard will be captivated in a plywood anatomy which gives it strength, protection, and a abode to arise the buttons and added hardware. You’ll additionally charge all of the LEDs for the affectation (46 in my case) and ping-pong assurance for the filigree (105 in total).
From the alpha I capital to complete this activity with genitalia on hand. I already had the atom of pegboard, and the plywood larboard over from architecture a wall-mounted lath for my office. Most of the cyberbanking accouterments was salvaged from addition activity (more on that later) and in the end I alone had to buy ping-pong balls, hot glue, and some ascent accouterments for the buttons. Here’s a account for the affectation itself, excluding the ambassador lath and buttons:
I aboriginal started by taping out the digits on a allotment of pegboard, again clamped a beeline bend forth the cut curve and acclimated a annular saw to trim it to size.
Pegboard is usually a bit chiffon so you should body a anatomy about it to accomplish it rigid. I’ve aloof got some abecedarian woodworking accoutrement so I’ve ripped 3″ plywood pieces, cut them to breadth with base joints, and again cut a dado the amplitude of the saw brand to accept the pegboard.
I bought this Kreg abridged spiral jig aback I was architecture my lath and I adulation it. Actuality I’ve cut abridged spiral holes into the ends of the continued rails. They base up to the ancillary balustrade and two screws will authority them nice and tight. You can get this jig for about $20, but if you don’t appetite to absorb the money aloof pre-drill and auger some holes from the alfresco and use copse screws to authority your anatomy together.
Here’s the alfresco of the accomplished box. All-in-all I’ve put about 90 account into the project. The majority of the time was spent barometer carefully, which you should booty seriously. One amiss cut could account an ad-lib acreage cruise for added supplies.
There’s affluence of allowance central for the base and ambassador board. Now to alpha inserting the LEDs.
I had a abundant time architecture the LED Jack-o-lantern but that accouterments has gone bare aback Halloween night. Actuality I’ve desoldered all of the apparatus from the protoboard and abrupt afar all of the LEDs, amid them by color. I’ll reclaim all of the blooming LEDs, the transistors, pin headers, some resistors, and abounding of the best affairs in this project.
Start by acute the LEDs into abode on the aback of the pegboard. They’ll be absolutely bound and I begin this action fabricated my fingers aching afterwards a while. I arrested anniversary LED application a array and resistor to accomplish abiding I had the polarity appropriate and that they all formed and were the aforementioned color. Aloft I’ve started soldering all of the cathodes for anniversary LED application award wire. The cathodes are aggregate by digit, and will be affiliated to arena by way of an NPN transistor.
Here all of the cathode access accept been made. I’ve acclimated affiliation wire to run anniversary of the four buses to one side, and amid them calm into a 4-channel KK connector. This will accomplish it accessible to bung the low end of the digits into a pin attack on the ascendancy board. Don’t balloon to hot-glue these affairs to the pegboard as a anatomy of ache relief.
Now it’s time to adhesive the anodes for the aforementioned pixel in anniversary chiffre together. I acclimated the decay pieces of award cable from the aftermost footfall in the action to do this. In the aerial appropriate you can see two award cables which accept IDC connectors blind over the side. The top array drives seven of the 13 LEDs in anniversary digit. The basal array drives the actual six. These will bung into bifold pin headers on the disciplinarian board, abutting the pixels through a resistor to a brace of about-face register. The colon in amid hours and account has been aggregate with the hour-tens chiffre which alone has pixels for the character 1.
Now it’s time to accomplish abiding aggregate works. We do charge to add ping-pong assurance as diffusers afore the affectation will be accomplished but if there’s a botheration you don’t appetite to accept to abolish the assurance to fix it. Let’s body and analysis the ascendancy dent now.
I capital to use genitalia on duke for this project. I’ve got affluence of 595 about-face registers but there’s one botheration with those; the accumulation pin has a 70 mA complete best rating. I can get about that limitation if I run my LEDs no college than 10 mA anniversary and breach the 13 complete pixels amid two about-face registers.
That takes affliction of the aerial side. To about-face the low ancillary of anniversary chiffre I’ve sourced 2N3904 NPN transistors. They accept a beneficiary accepted absolute of 200 mA which will accept no affair biconcave the 130 mA max advancing off of a chiffre aback the character 8 is displayed.
The multiplexing is handled by an ATmega168 active on the centralized RC oscillator at 8 MHz. This makes it a breeze to drive the affectation after any arresting artifacts, but it’s awful at attention time keeping. I had a Maxim DS3232 absolute time alarm on duke that will accumulate actual authentic clue of time. It has a advancement array which will accumulate time aback ability to the affectation is lost. This is absolute aback I intend to ability this from the bank outlets in my shop. I about-face them off aback I’m not alive and that agency the alarm will alone be aflame aback someone’s there to see it.
This how-to is advised to focus on the concrete body and not the cyberbanking design. If you accomplish your own it would be abundant bigger to accept about-face registers that action affiliated accepted on anniversary pin. This way the LEDs can be brighter and there’s no charge to anguish about blame up adjoin the accepted ratings of the about-face registers. Most affiliated accepted drivers are low side, which agency you would again use P-channel MOSFETS, PNP transistors, or agnate to about-face the aerial ancillary of anniversary digit. Basically the adverse of what I’ve done here.
Check out the LED attic cast for added on designing your own multiplexed displays. As for affiliated accepted drivers, there’s some nice accouterments acclimated in this whiteboard/LED covering project. Aloof don’t feel bound into Maxim genitalia as they can generally be difficult to source.
Having advised the ambit it’s aloof a amount of base it up and autograph some firmware.
Here’s the breadboarded circuit. You can see the two IDC connectors jumpered with resistors to the about-face registers on the breadboard. The chicken affairs to the appropriate affix the chiffre cathodes to their corresponding transistors. In the beginning is the DS3232 on a blemish board. You can see the bread corpuscle in its afraid holder. I’m application a multimeter to admeasurement the abundance of the 1 Hz aboveboard beachcomber this dent provides, and a Bus Pirate to see what’s activity on with the i2c communications. Now that it’s working, I aloof bare to acquisition a added abiding solution.
Voila! The top of the accomplished ambassador board. Note the two pin sockets to accustomed the DS3232 blemish board.
And the point-to-point soldering on the bottom. This took conceivably four hours to complete. It’s winter appropriate now and I don’t like application Cupric Chloride central to compose ambit boards so I went this route.
The aftermost allotment of the addle is abacus buttons. I knew I had this old ambit lath from a Sony shelf stereo system.
I bare four buttons so I acclimated a Dremel to abstracted this articulation from the beyond board. I added two holes to use for ascent and anchored affairs (reused from the pumpkin) absolute in addition KK connector.
Here’s a appearance of the base of the button board. I had to abolish the resistors that affiliated the buttons into a cast and I acclimated hot cement for ache relief.
After a cruise to Ace Accouterments I was able to install the button board. I started by archetype the area of the buttons on a allotment of paper, again application that as a arrangement to assignment holes through the top of the plywood case. You can aloof accomplish out the ragged aperture aloft anniversary button.
While and the accouterments abundance I best up a dowel as well. Actuality I’ve cut it to length, eased the top bend with some beach cardboard (I spun the dowel in a ability assignment for that), and added a aperture for a application pin.
Once installed I alert a accomplishment attach into the aperture of anniversary button dowel so they won’t abatement out.
Here’s the accomplished product. I adulation it!
Everything’s working, time to add the diffusers. I originally planned to buy ping-pong assurance from the dollar abundance but they alone had six 9-packs. I concluded up acclimation a gross online. I accomplished a aperture in anniversary brawl for the LED to stick through, again acclimated hot cement to attach them. Accomplish abiding the assignment $.25 you use for this are nice and sharp.
Here’s a analysis with the lights on.
And addition with the lights off.
I’m absolutely blessed with the way things angry out. If you body one yourself booty into application the use of affiliated accepted LED drivers as I mentioned before. Also, I had ablaze clear LED packages, you may appetite to agreement with broadcast packages. You can see that there is a ablaze point on the top of anniversary ping-pong brawl because of this. On the added hand, in ablaze ablaze you can still accomplish out the time because of those ablaze spots, so analysis this out afore you acquirement all of your parts.
When all is said and done the affectation allocation of this was accessible and quick to build. It took abundant best to adhesive the ascendancy lath and to accomplishment autograph the firmware. A articulation the git athenaeum is included in the assets area below.
Source cipher repository