We love the concept of using an LCD screen to transfer data. The most wide-spread and successful method we know of is the combination of a QR code and the camera on a smart phone. But for less powerful/costly devices data can be transferred simply by flashing colors on the screen. That’s what [Connor Taylor] is testing out with this project. He’s using a TEMT6000 light sensor to turn a white and black flashing monitor into binary data.
So far this is just a proof of concept that takes measurements from the light sensor which is held in front of a Macbook Retina display with different backlight levels. At 3/4 and full brightness it provides more than enough contrast to reliably differentiate between black and white when measuring the sensor with the Arduino’s ADC. What he hasn’t gotten into yet is the timing necessary to actually transfer data. The issue arises when you need to have multiple 1′s or 0′s in a row. We’ve tried this ourselves using an LDR with limited success. We know it’s possible to get it working since we’ve seen projects like this clock which can only be programmed with a flashing screen.
[Connor's] choice of the TEMT6000 should prove to be a lot more sensitive than using just an LDR. We figure he could find a way to encode using multiple colors in order to speed up the data transfer.
When we’re trying to get a relatively complex project to work we often end up with twenty windows open. When this happens we’re usually referencing multiple data sheets, webpages, and trying to write code that the same time. We’ve seen people with two or three monitors to alleviate the situation (often called a battlestation), but the we’re cheap and can’t justify buying more displays just for these occasions. Well [Oscar] may have the solution for us. His old laptop had been sitting in a box unused so he flipped the screen and built a stand to position it as an additional display on his desk.
The hack simply removed the screen for the hinged cover so that it could be flipped around. This turns the laptop into a tablet minus the touchscreen ability but that could always be added in later (we’ve seen it done with netbooks). He tells us that the only issue he ran into during this process was the length of the inverter cable. He simply cut it and spliced in a little bit of extra length.
[Oscar] didn’t write a post about his project, but you can see the build gallery after the break.
Continue reading “Use an old laptop as a second desktop display”
Not knowing what’s going on inside of your electronics projects can make it quite difficult to get the bugs out. [John] was bumping up against this problem when working on wireless communications between several devices. At just about the same time his friend came up with a script with lets you monitor multiple serial devices in one terminal window.
We’re used to using minicom, a Linux package that does the job when working with serial connections of all kinds. But [John] is right, we’re pretty sure you can only connect to one device per minicom instance. But [Jim's] Python serial terminal (available in this git repository) allows you to specify multiple devices as command line arguments. You can even use wildcards to monitor every USB connection. The script then automatically chooses a different color for each device.
The image above is from [John's] wireless project. Even without any other background this shows how easy it is to debug this way rather than tab back and forth between windows which gets confusing very quickly.
[Optec] want his own triple monitor setup built to his specifications. It turns out to have been a pretty easy project thanks to his mastery of stock materials. The image above is just a bit dim, but if you look closely you can see the strut channel which makes up the monitor frame.
When it comes to this type of metal strut material there’s a lot to choose from. [Optec] went with the half-slot format which provides a little bit of left and right wiggle room. This is important to get the edges of those monitors to butt up to one another. After making a pair of relief cuts he bent the channel in two places, using 45 degree brackets as reinforcement. The monitor mounts are made of MDF with countersunk holes to hide the bolt heads which connect it to the channel.
He figures the total cost of the mount was around $40. Seeing how easy it was makes us think we may never buy a commercial TV mounting bracket again. Of course if you’re more into woodworking there’s a tri-monitor project for you too.
It does make us sad to see all the waste generated as we move from CRT monitors and televisions to flat panel offerings. Here’s a way to cut down just a bit on how much is going to waste. [Denizpa] turned a CRT monitor into a planter.
The project is very straight-forward. First remove the plastic body from the electronic guts. Next you’ll want to choose your paint colors. While you’re at the home store, pick up a sanding sponge as well. [Denizpa] used 320 grit to sand all of the outside surfaces to help ensure the paint would bond well. Once the paint dried four plastic corner brackets were screwed in place to add some interest to the bottom of the planter. It’s not quite time to plant though, there’s way too many holes in the case to just fill it up with soil. A black plastic garbage bag serves as a liner and completes the project.
No mention on what to do with the guts you removed. If you have an idea let us know in the comments section.
[LuckyNumbrKevin] wanted an epic monitor array of his own but didn’t really have the desk real estate to pull it off. His solution was to build a three computer monitor mounting rack with a relatively small footprint.
The design started with some virtual test builds using SketchUp. Once he had it dialed in he began transferring measurements for the base onto some plywood. The rest of the parts are built using dimensional lumber. As the project shaped up he wrapped the edges of the plywood with some trim, and gave the piece a good sanding. After a few passes with a dark stain he was ready to mount the monitors he bought from Newegg.
[Kevin] left a comment in the Reddit thread about the parts cost for his design. Including the monitors, this came in under $300. That does not include the Nvidia graphics card which is capable of driving the trio.
One of the perks of writing for Hackaday is that we often find hacks that we’ve been meaning to do ourselves. Here’s one that will let us fix our borked ASUS computer monitor buttons. [Silviu] has the same monitor we do, an ASUS VW202, and had the same problem of stuck buttons. We already cracked ours open and realized that the buttons are not easily replaced (you’ve got to source the right one). We just unstuck the offender and vowed not to press that button again, but [Silviu] actually figured out how to disassemble and repair the PCB mount switches.
As with most consumer electronics these days the worst part of the process is getting the monitor’s case apart. The plastic bezel has little spring tabs all around it that must be gently pried apart. Once the PCB which hosts the buttons was removed, he took the metal housing off of the broken switch. Inside he found that a bit of metal particulate (leftovers from manufacturing?) were causing the problem. A quick cleaning with a cotton swab removed the debris and got the tactile switch working again.