[Peter]’s folks’ cable company is terrible – such a surprise for a cable TV provider – and the digital part of their cable subscription will only work with the company’s cable boxes. The cable company only rents the boxes with no option to buy them, and [Peter]’s folks would need five of them for all the TVs in the house, even though they would only ever use two at the same time. Not wanting to waste money, [Peter] used coax splitters can take care of sending the output of one cable box to multiple TVs, but what about the remotes? For that, he developed an IR remote control multidrop extender. With a few small boards, he can run a receiver to any room in the house and send that back to a cable box, giving every TV in the house digital cable while still only renting a single cable box.
The receiver module uses the same type of IR module found in the cable box to decode the signals from the remote. With a few MOSFETs, this signal is fed over a three-position screw terminal to the transmitter module stationed right next to the cable box. This module uses a PIC12F microcontroller to take the signal input and translate it back into infrared.
[Peter]’s system can be set up as a single receiver, and single transmitter, single receiver and multiple transmitter, many receivers to multiple transmitters, or just about any configuration you could imagine. The setup does require running a few wires through the walls of the house, but even that is much easier than whipping out the checkbook every month for the cable company.
Continue reading “Multi Input IR Remote Control Repeater”
For anyone who gets a late-night craving for anything out of the refrigerator and needs some help in the willpower department, [Claudio] may have the project for you. He has just finished work on a project that sends out an alarm when the refrigerator door opens, alerting others that you’re on the prowl for munchies.
The device uses a light sensor connected to an OpenPicus IoT kit that contains a FlyportPRO Wi-Fi module. When the refrigerator door is opened, the device sends out an email message via a web server, which can be sent to whomever you choose. All of the project’s code and instructions are available on the project site as well.
The project is pretty clever in that no actual interfacing with the refrigerator is required, beyond running a power cable through the seal of the door (although [Claudio] notes that the device will run on a lithium battery as an option). The web server itself can be set up to send out alarms during any timeframe as well, allowing a user to customize his or her nighttime snacking window. If you’re looking for a less subtle approach, we’d recommend the fridge speakers with a volume setting of 11.
Right now there are thousands of computers connected to the Internet, dutifully calculating SHA-256 hashes and sending their results to other peers on the Bitcoin network. There’s a tremendous amount of computing power in this network, but [Ken] is doing it with a pencil and paper. Doing the math by hand isn’t exactly hard, but it does take an extraordinary amount of time; [Ken] can calculate about two-thirds of a hash per day.
The SHA-256 hash function used for Bitcoin isn’t really that hard to work out by hand. The problem, though, is that it takes a 64 byte value, sends it through an algorithm, and repeats that sixty-four times. There are a few 32-bit additions, but the rest of the work is just choosing the majority value in a set of three bits, rotating bits, and performing a mod 2.
Completing one round of a SHA-256 hash took [Ken] sixteen minutes and forty-five seconds. There are sixty-four steps in calculating the hash, this means a single hash would take about 18 hours to complete. Since Bitcoin uses a double SHA-256 algorithm, doing the calculations on a complete bitcoin block and submitting them to the network manually would take the better part of two days. If you’re only doing this as your daily 9-5, this is an entire weeks worth of work.
Just for fun, [Ken] tried to figure out how energy-efficient the bitcoin mining rig stored in his skull is. He can’t live on electricity, but donuts are a cheap source of calories, at about $0.23 per 200 kcalories. Assuming a metabolic rate of 1500 kcal/day, this means his energy cost is about 67 quadrillion times that of an ASIC miner.
Continue reading “Mining Bitcoins with Pencil and Paper”
We have finally figured out what the Internet of Things actually is. It turns out, it’s just connecting a relay to the Internet. Not a bad idea if you’re building a smart, Internet-connected thermostat, but you have no idea how bad the security can be for some of these devices. The Heatmiser WiFi thermostat is probably the worst of the current round of smart home devices, allowing anyone with even a tiny amount of skill to control one of these thermostats over the Internet.
The Heatmiser is a fairly standard thermostat, able to connect to an 802.11b network and controllable through iOS, Android, and browser apps. Setting this up on your home network requires you to forward port 80 (for browser access) and port 8068 (for iOS/Android access). A username, password, and PIN is required to change the settings on the device, but the default credentials of user: admin, password: admin, and PIN: 1234 are allowed. If you’re on the same network as one of these devices, these credentials can be seen by looking at the source of the webpage hosted on the thermostat.
if you connect to this thermostat with a browser, you’re vulnerable to cross-site request forgery. If you use the Android or iOS apps to access the device with the custom protocol on port 8068, things are even worse: there is no rate limiting for the PIN, and with only four digits and no username required, it’s possible to unlock this thermostat by trying all 10,000 possible PINs in about an hour.
There are about a half-dozen more ways to bypass the security on the Heatmiser thermostat, but the most damning is the fact there is no way to update the firmware without renting a programmer from Heatmiser and taking the device apart. Combine this fact with the huge amount security holes, and you have tens of thousands of installed devices that will remain unpatched. Absolutely astonishing, but a great example of how not to build an Internet connected device.
You may be used to seeing rack mounted equipment with wires going everywhere. But there’s nothing ordinary about what’s going on here. [Elecia White] and [Dick Sillman] are posing with the backbone servers they’ve been designing to take networking into the era that surpasses IPv6. That’s right, this is the stuff of the future, a concept called Content Centric Networking.
Join me after the break for more about CCN, and also a recap of my tour of PARC. This is the legendary Palo Alto Research Company campus where a multitude of inventions (like the computer mouse, Ethernet, you know… small stuff) sprang into being.
Continue reading “Content Centric Networking and a tour of (Xerox) PARC”
This is an oldie, but oh, man is this ever good. It’s a Nixie clock made without a microcontroller. In fact, there aren’t any logic chips in this circuit, either. As far as we can tell, the logic in this clock is made with resistors, diodes, caps, and neon tubes.
The design of this is covered in the creator’s webpage. This clock was inspired by a few circuits found in a 1967 book Electronic Counting Circuits by J.B. Dance. The theory of these circuits rely on the different voltages required to light a neon lamp (the striking voltage) versus the voltage required to stay lit (the maintaining voltage). If you’re exceptionally clever with some diodes and resistors, you can create a counting circuit with these lamps, and since it’s pretty easy to get the mains frequency, a neon logic clock starts looking like a relatively easy project.
This clock, like a lot of the author’s other work, is built dead bug style, and everything looks phenomenal. It looks like this clock is mounted to a plastic plate; a good thing, because something of this size would be very, very fragile.
Video below, thanks [jp] for sending this one in.
Continue reading “A Nixie Clock with Neon Bulb Logic”
[Eugene] wanted to use his vintage Leica M4 as a digital camera, and he had a Canon EOS 350D digital camera sitting around unused. So he Frankensteined them together and added a digital back to the Leica’s optical frontend.
It sounds simple, right? All you’d need to do is chop off the back from the EOS 350D, grind the digital sensor unit down to fit into exactly the right spot on the film plane, glue it onto an extra Leica M4 back door, and you’re set. Just a little bit of extremely precise hackery. But it’s not even that simple.
Along the way [Eugene] reverse-engineered the EOS 350D’s shutter and mirror box signals (using a Salae Logic probe), and then replicated these signals when the Leica shutter was tripped by wedging an Arduino MiniPro into an old Leica motor-winder case. The Arduino listens for the Leica’s bulb-flash signal to tell when the camera fires, and then sends along the right codes to the EOS back. Sweet.
There are still a few outstanding details. The shutter speed is limited by the latency in getting the signal from the Leica to the 350D back, so he’s stuck at shutter speeds longer than 1/8th of a second. Additionally, the Canon’s anti-IR filter didn’t fit, but he has a new one ordered. These quibbles aside, it’s a beautiful hack so far.
What makes a beautiful piece of work even more beautiful? Sharing the source code and schematics. They’re both available at his Github.
Of course, if you don’t mind completely gutting the camera, you could always convert your old Leica into a point and shoot.