YourITronics

There are dozens of projects like this one on the web, but it’s nice to be able to chose the one you like most. Nothing special with this AVR ISP programmer, maybe just the idea that the author build it because hi’s hold programmer was working trough serial connection and as most modern devices work on USB he decided to make his programmer work on USB.

So, the solution was to replace the two transistors, that were used to adapt the RS-232 voltage levels to TTL voltage levels, with a USB to RS-232 chip such as FT-232BM.

USB ISP Programmer For AVR: [Link]

The circuit contains 2x TRW-24G modules, 1x AT90S2313 microcontroller and 1x MAX202 TTL to RS232 voltage level converter. When you power-on this circuit, the AVR it will configure the IC1 as receiver and IC3 as transmitter. I’m not gonna give you any more technical specifications because they are well documented on the authors page. I say you give it a try when you need to setup a wifi connections between AVR’s.

Experimenting Wireless Comunications With AVR ATtiny2313: [Link]

The RGBLED and mRGBLED controllers allow you to control the color of RGBLEDs.  This might sound trivial, but it actually takes a lot of resources to let you be able to set an RGBLED to any color you’d like.  In addition to just lighting an LED up with a given color, these boards also let you install a color or setup transition/animations effects.  They are easily controller via an RS232 connection (serial port) or an SPI connection (logic level).

The boards can be built reasonably inexpensively and there are PC boards available for either model.  All source code for the onboard PIC processor as well as the software for configuring and using the controllers is available.  The protocol is a simple protocol well documented.

I’m currently studying timers and pwm control on AVR’s so i can build my own projects related to controlling RGB LED’s. I hope I’ll get something up soon.

RGB LED PWM Control Project: [Link] - [via]

I say another, because we all know the DIY MP3 Player and the AVR Butterfly MP3 Player. This mp3 player can support up to 4 GB of storage (MMC or SD cards) runs from a single AAA battery and has full user control (volume, track, pause, skip, directory) with a 5-way micro joystick.

Also the LCD has contrast control, you can record voice and the firm-wire is totally upgradeable trough RS232. In fact this DIY MP3 player is the coolest I’ve seen so far and it’s full of tricks.

EchoMp3 Another DIY MP3 Player: [Link]

AVR Butterfly is an evaluation tool demonstrating the capabilities of the latest AVR Technology. The tool is shipped with preloaded firmware supporting temperature sensing, light measurement, voltage readings and music playback. The AVR Butterfly is controlled by an ATmega169.

It’s basically the cheapest development board on the market, $21.28 as we’re speaking at Digikey. I choose to start with the AVR Butterfly because it is also featured in all examples in the tutorial I’m reading. The tutorial is easy to follow and i recommend it if you want to start programming AVR’s in C language. You can find it at SmileyMicros.

The tutorial contains all you need to now, but some things are not entirely covered, and other things present incompatibility issues.

When ordering the Butterfly its also a good idea to order some pin headers because they are not included. When you take the Butterfly out of the box it should look like this:

Now it would be nicer if they would of included those pin headers in the package. And here is my Butterfly after i soldered the pin headers.

Another thing that i noticed about this step, is that my Butterfly doesn’t have the LDR, it seems that this version only comes with the NTC soldered on the back, which is also an analog sensor and it should be enough for developing code with analog sensors.

The next important thing that you need to solder is the RS232 cable, because the communication between the computer and the Butterfly is done via RS232.

Hers is a picture of my cable, and how it should be done. (disregard the connector i used, its taken from an old computer case, that’s why its saying turbo sw).

Notice how the RXD and TXD from Butterfly are reversed on the RS232 connector ? That’s because what you transmit here has to be received there. Pay attention on soldering this connector, you will avoid future headaches. But what if you don’t have an RS232 connector on your computer ? the answer is simple you buy a RS232 to USB converter cable, like i did:

I could of done myself the cable using the schematic from this article, but the parts cost more than a commercial cable, not to mention the hours you put in fabricating.

Now about the battery, the onboard CR2450 isn’t gonna last too long with the projects that you’re gonna work with. So its best to build an external power supply. I build mine with 2 x AA-R6 battery holder.

From this step on, you can approach things two ways, either use a breadboard or fabricate PCB’s. I don’t have a breadboard so i had to make pcb’s. Basically its just a board with 8 LED’s, 8 current limiting resistors and some headers for linking it to the Butterfly.

here is the Eagle schematic and board file.

details on how to fabricate the PCB are covered in my DIY PCB Tutorial.

Here are a couple of pictures with the board after being etched and after being assembled. The 8 LED board is going to be used with the Blinky Project.

I also did two small PCB’s for driving an RGB LED, one for a CA version and one for CC version.(Common Anode and Common Cathode). I will use this boards later when i will be experimenting with PWM control.

Here are the RGB LED boards assembled.

And to end this article here is a picture with the USB to RS232 cable connected to the AVR. Now all i have to do is read and learn the next 300 pages from the tutorial.

Now i started working on a lab power supply, i could of just buy one but its more fun to build it. Here is a picture where i just started the assembly. The project should be up soon at my personal projects page.