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.

Continue reading “Synthesizing sound with a light sensitive pen and CRT television”

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.

Continue reading “LED headgear is marvel of free-formed circuitry”

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!”

Augmented reality game could come from the seventies

[Niklas Roy] sent in a project he just completed called PING! Augmented Pixel. At first glance the entire build is just a plain jane retro video game stuffed into an ATmega8 but looks can be deceiving. The video game is actually an augmented reality device that inserts a pixel into a video feed. The bouncing pixel can be manipulated with a camera – push the pixel and it goes off in another direction.

The project runs on an ATmega8 clocked at 16 MHz, and reads the video feed with the help of an LM1881 sync separator. There’s no schematics, but he thankfully included some code for his project. Everything is set up for PAL video, but this could be easily adapted for NTSC. Any Hack A Day readers want to take up the challenge of building this from just a description?

[Niklas] says there’s no reason this couldn’t have been done by Atari in the late seventies. There were economic reasons for not putting out a video camera controller, of course, and the R&D department may have been too busy playing Breakout with their eyebrows.

Check out the demo of the augmented pixel after the break.

Continue reading “Augmented reality game could come from the seventies”

Build your own Programmable Logic Controller

[Q] is an Electrical Engineer who works in an industrial setting. He frequently uses Programmable Logic Controllers at work but had never built one himself. He decided to undertake the project at home and managed to build a PLC that outputs 120V AC or 12 V DC and has optoisolated inputs.

On the circuit board you’ll find an ATmega8 and an EEPROM for extra data storage. Six outputs are controlled by relays since they are able to output either alternating or direct current. There are eight inputs which use optical isolators as buffers to protect the microcontroller.

So what did he end up using this for? It was part of his Christmas light setup last year. The image above shows the PLC in a water-tight electrical box with extension cords running to each of the devices he wishes to control. The example code is what he used on the X-mas setup, but it should be enough of a guide to program this to work with just about any application.