Build an intervalometer with these simple fabrication techniques

[L] just finished building this intervalometer and his verbose documentation of the project has a little bit of everything. The fabrication uses common prototyping materials, and simple skills that are easy to master even for the beginner.

The hardware is based around an ATmega8 microcontroller. After snooping around the Internet [L] wanted to see if the voltage divider based focus and shutter commands that are present in some camera remote shutter controls would work for his model. Investigation with a commercial shutter release showed him how it was done, so he incorporated that into his design. When it comes to firmware for the device we really like his explanation of the menu system. There’s a lot of settings and he did a great job of planning the user interface to make them all work on the finished product.

The schematic and board layout were done with Eagle. During the layout process he made choices for easy assembly using strip board, and even walks us through the steps when cutting the traces and adding jumper wires. It’s nicely finished in this clear plastic case and demonstrated in the video after the break.

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Over-engineering a two-zone thermometer

We love the extra touches that [Andrianakis Haris] added to his two-zone electronic thermometer. It includes features that you just wouldn’t find on a mass-market commercial product because of issues like added cost. For example, you can see that the PCB juts up above the LCD display, allowing the module to be mounted on a pair of screws thanks to the keyhole shape that was drilled in the substrate. I increases the board size greatly, but on a small hobby run this won’t usually affect the price of the board depending on the fab house pricing model.

The design uses an ATmega8 microcontroller to monitor sensors in two different places. There is an onboard LM35 temperature sensor for monitoring the space where the unit resides. A remote sensor module uses a DHT-11 chip to gather data about temperature and humidity. That sensor is wired, but there is one wireless option for the device. Data can be pulled down from it via an optional Bluetooth module which can be soldered to a footprint on the back of the board.

Check out the video after the break to see temperature readings pulled down wirelessly. Continue reading “Over-engineering a two-zone thermometer”

Using an ATmega8 to program PIC24FJ chips

[Fezoj] likes to play around with microcontrollers and decided that he wanted to try a Bus Pirate as a new tool in his adventures. Since it’s open hardware he had his own board made and populated it himself. The trouble is, he works only with AVR chips and doesn’t have a PIC programmer. No problem, he figured out how to flash the PIC24FJ using an ATmega8.

To get started, he grabbed a copy of the flash programming specifications from Microchip. Once he had implemented the protocol in the AVR code, it was just a matter of getting the downloaded PIC firmware to the AVR. An RS232 chip gives him the serial connection he needs, with the help of his own programming software written with Visual Studio.

It’s not a robust solution for prototyping on the PIC platform, but maybe it could be developed for that purpose. For now, all he needed was a bootloader so that he could flash the Bus Pirate via a USB connection.

[via Dangerous Prototypes]

Synthesizing sound with a light sensitive pen and CRT television

Here’s the latest project from [Niklas Roy’s] workshop. Lumenoise is an audio synthesizer controlled by drawing with a light-sensitive pen on a CRT television.

The pen is a self-contained module which connects to the TV via audio and composite video RCA plugs. Inside the clear pen housing you’ll find a microcontroller which generates the audio and video. The business end of the pen contains a phototransistor which lets the ATmega8 take a reading from the video screen. Since the chip is generating that video signal, it’s possible to calculate the pen tip’s position on the screen and modulate the sound output based on that data. You can watch a recording of the results in the video after the break.

This is a very simple circuit to build, and [Niklas] makes the point that most of us have a CRT hanging around in a dark corner somewhere. We think this would be a fantastic¬†soldering¬†project to do with the kids, and that this would be right at home as a children’s museum piece because of the wow factor involved in playing around with it.

We can really tell from this and some of his past projects that [Niklas] just loves the 8-bit audio.

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Snooping around in the iclicker hardware and firmware

[Arko] was compelled to purchase an iclicker to use in some of his college courses. It’s similar in size to a television remote control except it only has six buttons and it communicates via radio frequency instead of infrared light. The idea is that classrooms have a base station that the instructor uses, and he or she can ask questions of the class and have instant feedback. Results are often projected on a screen for all to see but only the instructor can get at the breakdown of who answered in what way. In [Arko’s] case, the class awards participation points that you can only get by using this device. He decided to actually learn something from the expenditure by reverse engineering the device.

Preliminary hardware inspection told him that it uses an ATmega8 microcontroller and there’s a standard 6-pin ISP footprint just waiting to be populated with a surface mount pin header. Once he soldered on that header, he tried to read out the firmware but the iClicker reset itself. He guessed that there was something going on with the power and ground lines so he soldered directly to them and was able to dump the data–the security fuses are not set. He goes on to snoop in the EEPROM to find where the device ID is stored, and then to watch some of the SPI communications to see what the microcontroller is sending to the radio chip. But there’s a lot left to discover and he’s planning at least two follow-up post to share what he finds.

Just looking to repair your dead device? Check out this tip on battery problems with the iclicker.

LED headgear is marvel of free-formed circuitry

Hackaday contributor [Nick Schulze] popped out an impressive set of LED headgear for a hat-themed party.

[Nick] is no stranger to working with LEDs. Previously he built a blue 8x8x8 cube something like this other 512 node full color version. He had a bunch of LEDs left over from that project and decided to put them to good use.

The first part of the build is the frame itself, made from thick fencing wire. He just started bending it around his head and got an uncomfortable head-shaped hoop to which he could solder. From there, enameled copper wire wraps its way through the system, supplying logic levels to all of the LEDs. Everything is done without a circuit board of any kind. The LED drivers themselves are attached by first using a zip tie to affix a resistor to the frame, then by soldering the TLC5916 chip to that resistor. Even the ATmega8 is included dead-bug style by soldering it to the frame which we think servers as ground. Program it with the free-floating female pin header and you’ll get the fantastic animations seen in the video after the break.

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Your snapshot on a thermal printed receipt, instantly!

What could be better than a low-res black and white photograph printed instantly on paper that will yellow and crumple over time? Wow, we really need to work on our sales pitch. But all kidding aside, we love the idea that [Niklas Roy] came up with in order to build this thermal printing camera.

His Picasa album has two snapshots of the hardware. He’s using an LM1881 for video sync separation just like he did with his PING project. From there an ATmega8 microcontroller grabs each column from the image and prints it using the thermal printer. It looks like everything runs on a 9V battery which is nice for portability (although we still never got our hands on that rechargeable 9V we’ve been meaning to pick up). Perhaps just as impressive is that [Niklas] got this up and running with about 400 lines of code. Nice!

Of course you’ll want to see this in action so we’ve placed a video clip after the break. Just like old-timey cameras it looks like you’re going to need to sit still until the image is done printing.

Continue reading “Your snapshot on a thermal printed receipt, instantly!”