Dumping U8Plus Smartwatch ROM Via Vibration Motor

February 10, 2016 by Al Williams 24 Comments

[Lee] continues with his exploration of the U8Plus (a cheap smartwatch). He hasn’t got it all cracked, yet, but he did manage to get a dump of the device’s ROM using an unusual method. At first, [Lee] thought that the JTAG interface (or, at least, the pins presumed to be the JTAG interface) would be a good way to explore the device. However, none of the people experimenting with the device have managed to get it to work.

Instead, [Lee] went through the serial bootloader and dumped the flash memory. He found out, though, that the bootloader refused to read the ROM area. It would, however, load and run a program. Unfortunately, no one has found how to access the UART device directly, but they have found how to drive the vibration motor.

[Lee] took off the vibration motor and used it as an output port for a simple program to dump the ROM. An Arduino picked up the data at a low baud rate and produced an output file. This should allow more understanding of how to drive the watch hardware.

We covered the initial teardown of this watch earlier this year. Of course, if you don’t want to reverse engineer a smartwatch, you could always build your own.

Remote-Controlled Eyebrows For Your Birthday

February 10, 2016 by Elliot Williams 15 Comments

We’re not sure that [Alec]’s dad actually requested remote-controlled eyebrows for his birthday, but it looks like it’s what he got! As [Alec] points out, his father does have very expressive eyebrows, and who knows, he could be tired of raising and lowering them by himself. So maybe this is a good thing? But to us, it still looks a tiny bit Clockwork Orange. But we’re not here to pass judgement or discuss matters of free will. On to the project. (And the video, below the break.)

An ATmega328 (~~otherwise known as cheap Cloneduino~~ Alec wrote that the 328 was from a real Arduino) is trained to run motors in response to IR signals. An L293D and a couple of gear motors take care of the rest. Sewing bobbins and thread connect the motors to the eyebrows. And while it’s not entirely visible in the photo, and veers back into not-sure-we’d-do-this-at-home, a toothpick serves as an anchor for the thread and tape, secured just underneath the ‘brows for maximum traction.

We have to say, we initially thought it was going to be a high-voltage muscle-control hack, and we were relieved that it wasn’t.

Continue reading “Remote-Controlled Eyebrows For Your Birthday” →

A Wireless Wood Stove Monitor

February 8, 2016 by Kristina Panos 25 Comments

[Michel] has a wood stove in his basement for extra heat in the winter. While this is a nice secondary heat source, he has creosote buildup in the chimney to worry about. [Michel] knows that by carefully monitoring the temperature of the gases in the chimney, he can hit the sweet spot where his fire burns hot enough to keep the creosote under control and cool enough that it doesn’t burn down the house. To that end, he built a wireless wood stove monitor.

The first version he built involved an annoying 20 foot run between the basement and living room. Also, the thermocouple was mounted on the surface and made poor contact with the chimney. Wood Stove Monitor 2.0 uses a probe thermometer on an Exhaust Gas Temperature (EGT) thermocouple to measure the temperatures. The intel is fed to a thermocouple amplifier to provide a cold-compensation reference. This is shielded so that radiant heat from the stove doesn’t compromise the readings. An nRF24L01+ in the basement monitoring station communicates with another module sitting in the living room display so [Michel] can easily find out what’s going on downstairs. When it’s all said and done, this monitor will be part of a bigger project to monitor power all over the house.

Interested in using a wood stove to help heat your house? Why not build your own?

Another Use For Old Hard Drive Parts: Anemometer

February 7, 2016 by Elliot Williams 39 Comments

So you’ve just taken apart a hard drive, and you’re looking at all the pieces on your desktop. You’re somehow compelled to use them all in different projects. Why not pull out that very high quality bearing that keeps the platters spinning at high RPMs and build this simple anemometer with it? That’s what [Sergei Bezrukov] did, and it looks like a perfect el cheapo project.

The build is fairly low-tech and entirely sufficient. The cups are made from plastic containers that used to contain pantyhose. A Hall-effect sensor and a magnet take care of measuring the rotations, feeding its signal into a PIC that calculates the wind speed from the revolution rate. The rest of the housing is PVC, with some other miscellaneous parts found at the hardware store.

To calibrate the device, [Sergei] made a second hand-held unit that he could (presumably) drive around in a car to get a baseline wind speed, and then note down the revolution rate. Once you’ve got a good reference, holding the portable unit up to the permanent one transfers the calibration.

But the star of the show, that lets the anemometer spin effortlessly, is the sweet bearing that used to spin a hard-drive platter. If you haven’t played with one of these bearings before, you absolutely should. We just ran a post on taking apart a hard drive for its spare-parts goodness so you have no excuse. If you’re feeling goofy, you can mount one onto a board, step on it with the ball of your foot, and spin. They’re quality bearings, and you’ll be surprised how quickly you can spin as you pull your arms in.

Thank [Matt] for the tip!

A DOS Education In Your Browser

February 5, 2016 by Al Williams 32 Comments

In the 1970s and 1980s, a lot of us learned to program using good old-fashioned BASIC on machines ranging from Altairs, Commodores, Apple IIs, and the like. Sometime in the 80’s the IBM PC running MSDOS because the de facto standard, but it was still easy enough to launch BASIC and write a simple little program. Of course, there were other programs, some serious like C compilers, some semi-serious like flight simulators, and some pure fun like Wolfenstein 3D.

If you read Hackaday, you’ve probably noticed that a lot of people emulate old computers–including old MSDOS PCs–using a variety of techniques, including Raspberry PI boards running DOSBox or another emulator. Honestly, though, that’s a lot of effort just to run some old software, right? You can load up DOS emulators on your desktop too. That’s a little easier, but you still have to find software. But if you are as lazy as we are, you might want to check out the MSDOS collection at archive.org.

Continue reading “A DOS Education In Your Browser” →

Very, Very Low Power Consumption

February 5, 2016 by Brian Benchoff 27 Comments

We’re pretty far away from a world full of wall-warts at this point, and the default power supply for your consumer electronics is either a microUSB cable or lithium batteries. USB ports are ubiquitous enough, and lithium cells hold enough power that these devices can work for a very long time.

USB devices are common, and batteries are good enough for most devices, not all of them. There is still a niche where& extremely long battery lifetimes are needed and tapping into mains power is impractical. Think smoke detectors and security systems here. How do power supplies work for these devices? In one of the most recent TI application notes, TI showed off their extremely low power microcontrollers with a motion detector that runs for ten years with a standard coin cell battery. This is one of those small engineering marvels that comes by every few years, astonishing us for a few minutes, and then becomes par for the course a few years down the road.

The first thing anyone should think about when designing a battery-powered device that lasts for years is battery self-discharge. You’re not going to run a battery-powered device for ten years with a AA cell; the shelf life for an Energizer AA cell is just 10 years. Add in a few nanoAmps of drain, and you’ll be lucky to make it to 2020. The difference here is a CR2032 lithium-ion coin cell. Look at the datasheet for one of these cells, and they can easily sit on a shelf for 10 years, with 90% of the rated capacity remaining.

With the correct battery in the device, you’ll need a microcontroller that runs at a sufficiently low power for it to be useful in the mid-2020s. The product for this is the CC1310, a very, very low power ARM Cortex-M3 and sub 1GHz transmitter in one package.

Once that’s settled, it’s simply a matter of putting a sensor on the board – in this case a PIR sensor – and a few analog bits triggering an interrupt occasionally. Have the microcontroller in sleep mode most of the time, and that’s how you get a low-power device with a battery that will last a decade.

Bubble Free Resin Casting With A Modified Paint Tank

February 5, 2016 by Gerrit Coetzee 19 Comments

[thelostspore] was experimenting with resin casting, and discovered that he needed a pressure casting chamber in order to get clear casts. There are commercial solutions for sale, and they are really nice. However, many hackers are on a budget, and if you’re only casting every now and then you don’t need such a fancy set-up.

Re-purposing equipment like this is pretty common in the replica prop making community. Professional painters use a pressurized pot filled with paint to deliver to their spray guns. These pots can take 60-80 PSI and are built to live on a job site. By re-arranging some of the parts you can easily get a chamber that can hold 60 PSI for enough hours to successfully cast a part. Many import stores sell a cheap version, usually a bit smaller and with a sub-par gasket for around 80 US Dollars. [thelostspore] purchased one of these, removed the feed tube from lid and plugged the outlet. He then attached a quick release fitting to the inlet of the regulator.

We used this guide to build our own pressure casting set-up. Rather than plug up the outlet on ours, we put a ball valve with a muffler in its place to quickly and safely vent the chamber when the casting has set. We recommend putting a female quick connect coupling or another ball valve in combination with the male fitting (if your hose end is female). It is not super dangerous to do it the way the guide recommends, but this is safer, and you can disconnect the compressor from the tank without losing pressure.

All that was left was to test it. He poured an identical mold and it came out clear!