As convenient as cell phones are, sometimes these power-hungry devices let us down right at the worst time. We’re talking about battery life and how short it is in modern cell phones. Sure that’s totally inconvenient sometimes but it could be way worse. For example: during a natural disaster. A cyclone hit [Ganesh’s] home city and the entire area had lost power for 10 days. He couldn’t plug in his phone to charge it even if he wanted to. After realizing how dependent we are on the electrical grid, he did something about and built a phone charger out of parts he had kicking around.
The charger is quite simple. The user cranks on a DC motor and the output power goes into a LM2596-based step-down voltage regulator. The output of the regulator is then connected to a female USB connector so that any USB cord can be plugged in. As long as the motor is cranked fast enough to put out at least 8vdc, a steady stream of 5v will be available at the USB connector. Max current output of the system has been measured at 550mA.
[Ganesh] admits this isn’t a practical every-day charger but in a pinch it will certainly do the trick. It is even possible to build a makeshift charger out of a cordless drill.
Continue reading “DIY Phone Charger Born From Cyclone Disaster”
There’s pandemonium on the streets. You look down from your 4 story apartment and see hundreds of people marching and chanting. You pick up your phone and call your buddy, expecting it to link up to the nearest cell tower which will route your call to where it needs to go. Instead, without your knowledge, you link to a tricked-out police surveillance truck a few blocks away. They intercept your call and listen to the conversation in hopes of tracking the protest.
Continue reading “Ask Hackaday: Stopping The Stingray”
Thanks to the worldwide proliferation of smartphones, tiny high-resolution displays are common and cheap. Interfacing these displays with anything besides a phone has been a problem. [twl] has a board that does just that, converting HDMI to something these displays can understand, and providing a framebuffer so these displays can be written to through small microcontrollers.
[twl] is using a rather large FPGA to handle all the conversion from HDMI to the DSI the display understands. He’s using an Xilinx Spartan-6-SLX9, one of the most hobbyist friendly devices that is able to be hand soldered. Also on the board is a little bit of SDRAM for a framebuffer, HDMI input, and a power supply for the LCD and its backlight.
On the things [twl] has in his ‘to-do’ list, porting Doom to run on a cellphone display is obviously right at the top. He also wants to test the drawing commands for the Arduino side of his board, allowing any board with the suffix ~’ino to paint graphics and text on small, cheap, high-resolution displays. That’s a capability that just doesn’t exist with products twice [twl]’s projected BOM, and we can’t wait to see what he comes up with.
You can check out the demo video of [twl]’s board displaying the output of a Raspberry Pi below. If you look very closely, you’ll notice the boot/default screen for the display adapter is the Hackaday Jolly Wrencher.
Continue reading “Using Cell Phone Screens with any HDMI Interface”
It’s happened. It’s finally happened. In a move that has hipsters donning their good flannel and breaking out that case of Genesee they were saving for a special occasion, the rotary cell phone is now a reality.
[Jaromir] created this astonishingly retro future device as an entry for the NXP LPC810 challenge, a contest to do the most with an ARM Cortex M0+ microcontroller in an 8-pin package. Having only six I/O pins for controlling a GSM module, display a few buttons, and the fancy rotary dial meant [Jaromir] needed to expand his I/O some way. He chose a shift register to handle the buttons and display in a somewhat impressive demonstration of using a shift register as both an input and output expander at the same time.
From the videos [Jaromir] uploaded, the rotary cell phone isn’t ready for Think Geek to do a production run quite yet. He needs to enter the PIN for the SIM card, AT commands for the GSM module, and is, of course, a horrible method of user input for the younglings who have only seen rotary phones in old movies. That being said, it’s a rotary cell phone running on an 8-pin microcontroller. What more do you want?
Videos of this awesome this truly awesome phone in action below. If you’d like to build your own – and why wouldn’t you – all the files are available on [Jaromir]’s git
Continue reading “The Rotary Cell Phone”
If you’re like us, you probably have a box (or more) of wall warts lurking in a closet or on a shelf somewhere. Depending on how long you’ve been collecting cell phones, that box is likely overflowing with 5V chargers: all with different connectors. Bring them back to life by doing what [Martin Melchior] did: chop off the ends and solder on a bunch of USB jacks.
You’ll want to use chargers rated for at least 500mA (if not 1A) for this project, or you may be wasting your time considering how much current devices pull these days. Get your polarity right, solder on a USB jack, and you’re finished. Sure, it’s a no-brainer kind of project, but it can clean out some of your closet and give you a charging station for every room of your home and the office. [Martin] glued the USB jack directly onto the adapters, so there are no tangled cords to worry about. iPhone users will need to do the usual kungfu if you want your Apple device to charge.
Since our ‘ol buddy [Caleb] left Hackaday for EE Times, he’s been very busy. One of his latest projects is doing Antique Electronics Autopsies. This time around it’s a 1953 Heathkit Grid Dip Meter. It’s a beautiful piece of engineering with Point to Point wiring and metal gears.
We love microcontroller breakout boards, and so does [Tim] apparently. He built a breadboard friendly breakout for the NXP LPC812. It’s an ARM Cortex M0+ with 16kb of Flash and 4kb of SRAM. The entire breakout board is smaller than the through-hole DIP LPC1114. When are we going to see these on Tindie, [Tim]? Here’s the Git with the board files. You can also pick up a board at OSH Park – $3.30 for a set of three.
What do you do when you have the perfect idea for a Kickstarter, but don’t have the funds for the perfect sales pitch? The obvious solution is to start an Indiegogo campaign to raise funds for your Kickstarter. Unfortunately, this campaign has already been successfully funded, so it’s already too late to get in on the ground floor. Relevant xkcd.
We’ve seen this DIY cell phone before but now it’s just about ready for production. [David] at the MIT Media Lab has been working on a bare-bones, ATMega & GSM module phone for a while now, and now you can grab the firmware and board files. Make your own cell phone!
Here comes Hanukkah, so drink your gin and tonica. Here’s a pedal powered menorahica so put on your yarmulke, it’s time to celebrate Hanukkah.