A great tool for microcontroller hacking activities you might want to take on in the future is the Baudrate Converter, a device that automatically detects the baud rate of an MCU-based device you wish to hack. Using this method makes things a lot easier, so you don’t have to detect the actual baud rate using the PC or an oscilloscope – it saves a lot of time and energy and it’s also pretty simple to make.

The usual serial transmission has the Tx line on ‘high’ when idle and a single byte starts with a ‘low’ value (the startbit) and ends with a ‘high’ value (the stopbit). The idea is that, based on a few characters, the device measures the times the signal is ‘low’ and sorts them lowest to highest, detecting the real bit-time.

The baud rate converter uses the ATtiny2313 microcontroller from Atmel and the FT232 USB UART chip from FTDI. The latter supplies the power for the ATtiny. The converter has no capacitors for the crystal and runs at 20MHz using a 3.3V voltage, but it seems to be working nonetheless. The software that makes everything work is written in C and uses the 16-bit timer of the ATtiny extensively. After you connect the unknown serial port and send a few characters via a terminal-emulator, the device will detect the baud rate and the transmission of the bytes will be done accordingly, using the appropriate baud rate. If errors are detected, the converter will repeat the autobauding process.

The device has a detection range from 110 to 115200 and can help a great deal if you encounter baud rate conversion difficulties. The source code is available for released under GPLv3 license and is available for download in the link below (a .hex file is also available).

Baudrate Converter: [Link]

These days most pharmacies use LED pharmacy crosses posted at their entrance to let people know there is a pharmacy there. The reasons are obvious, they look cool&hi-tech, they can be seen from distance and they can be customized really easy (well, easy customizing pretty much depends on how the manufacturer approaches things).

If you try to search the web about schematics or example codes for this kind of circuit you wont find any, and again i think the reason is obvious, the crosses are quite expensive and so is the profit for the manufacturer. So nobody is gonna post schematics for such a project, unless you’re a hobbyist and you’re having fun with electronics.

The project consists of one ATmega64, three ULN2003 and five 5×7 LED matrix from Kingbright(TA20-11EWA). I had the idea to build something like this but so far i haven’t had the time nor the knowledge to get it done. So i asked Morgoth if he would like to participate in the project. I sent him the LED’s, the drivers and the PCB and he started working. As you can see not many parts are involved , but the secret lies in the microcontroller, it’s the programming that does the job.

In the next pictures you can see the microcontroller board with the ULN2003 darlington arrays:

The circuit was designed to receive messages trough serial interface from a computer and than display them. Morgoth also designed a custom terminal for windows which provides easy access to the display.

In this test phase a serial interface by wire was used to transmit data between the terminal and the ATmega64, but a wireless or bluetooth module could be integrated with no problem.

Also as a note, the LED’s don’t light up really bright, for that to happen you need to use drivers on the positive rail. This also applies if you’re planning to take the project to another level and use bigger LED’s

And now, watch some videos with the LED Pharmacy Cross beeing controlled from the computer:

• LED Pharmacy Cross ATmega source code
• LED Pharmacy Cross terminal source code

This is the reconstruction of a “Fakespace GL-8001” device with fully compatible serial interface via USB. This device fits into a very small SubD adapter housing, consumes low power (max. 20 mA), supports USB standby, may support a USB remote wakeup feature later, is much faster in responsiveness than the GL-8001, and the electronic components are fairly cheap, lower than 5 €.

Data gloves with miniaturized USB controlling device: [Link]

Parallel interfacing LCD with MCU  needs at least 6 I/O pins (4 bit mode) and maximun 11 I/O pins (8 bit mode). The I/O pin’s can be cut down to 3 pin by serial interfacing using shift registers. There are a few shift registers that can be used such as 74HC164, 74HC595, CD4094 and other compatible 8 bit shift register. Before you attempt to do serial interfacing, it helps to get familiar with parallel interfacing, you can find many reference from internet.

Serial interfacing LCD with PIC Microcontroller: [Link] – [Via]

And here is another infrared receiver, although its name says its universal that doesn’t mean the other Infrared Receivers aren’t. The project page first presents a MCU version of the receiver based on several types of PIC’s and than the symplified version without MCU, the one i also wrote about here. The goal is the same as for the other infrared receivers, to control your computer with any remote controller you have (TV, VCR, CD or Stereo).

UIR – Universal Infrared Receiver: [Link] – [Via]

These day’s most computers and laptops don’t have the RS232 port installed so if you can only connect something trough RS232 you’re looking at a problem. This project comes in handy, and gets you out of the problem. It’s really simple, few parts are involved and if you do it with SMD parts it can be pretty small(like in the picture).

USB to Serial (RS232)  Adapter: [Link]

This device transforms your PC into a powerful controller that you can use to program and automate machines, circuits, or just about anything you can imagine. Its flexible 29 I/O ports that you can configure to work ( bit by bit or in groups) as inputs or outputs makes it adaptable to a wide array of applications . Control of stepping motor system is unbelievably easy, thanks to its built-in Pulse Generator function. It even has encoder switch input functions, counting inputs, and port capture register. It is Visual Basic friendly, and more!

29 I/O Serial I/O PC Automation: [Link] – [Via]

This project is really easy to build, anyone can try it. After reading this tutorial anyone can build this. You just need the tools and the parts list and you can start building it. I first build this project about 2-3 years ago when I found the schematic on a website I don’t remember which website, and I gave it a try. Surprise, it worked! And it worked fine.

The receiver it’s very sensitive, you can send signals with a TV remote from 10 m away very easy. You don’t even need to point the remote at the receiver, it’s so sensitive it picks the signal that bounces from objects or walls. And if you think at the cost of this project parts list, it’s really cheap, about $4. You can build this on a board or just connect the parts between them.

There are various modes of assembly of this project: you can build the hole circuit inside the RS232 connector so only the IR sensor comes out, or you can build the circuit inside the connector and attach a wire with the sensor at the end. You can assemble it however you want. This is the schematic of the receiver, you can see that it uses an IR detector, a resistor, a diode, a capacitor and an rs232 serial connector. Very simple indeed.

If you take a look at the ir detector code the last two digits represent the frequency at which the IR detector receives signals. I successfully used different frequency ir detectors and all of them worked with any remote I had around the house. If you encounter problems with some kind of remote you should try changing the IT detector with one of another frequency(it is optimal to use the 38 KHz receiver).

After building the receiver connect it to your com port and lets talk a bit about the software part. The receiver needs a software that is going to decode the signals and control various other programs that you want to control. As a software you can use a free software named Winlirc or Girder which you can buy for about 40 $(note Girder must be use together with a plugin that recognizes signals coming from our receiver, the plugin is named Igor and you can download it from link1 or from link2 there are 2 versions available , you should try the first one and if that doesn’t works the second one will work).

I’m going to teach you how to use the receiver with girder and Igor plugin because this is what I used. After installing Girder you have to install the Igor plugin , if you encounter any problems you can check the plugin’s website for answers or you can write a comment here and I will be happy to answer you. Now after you plug in the receiver start Girder.

Now you have to go to configuration to hardware plugins and check Igor SFH-56 device and set the correct com port.(click Link to see a picture explaining configuration of Igor plugin).Now your software is ready to receive signals from the receiver. Now the small green led in the lower right side of Girder should blink every time you press a button on your remote signaling the software is receiving signals. Now all you have to do is start configuring Girder to control various other programs by learning different keys and their action. Here are some pictures of assembled receivers:

And here is the part list:

• TSOP 1738 : ir receiver x1
• resistor 3k3 x1
• capacitor 100 nF x1
• z diode 5v1 x1
• rs232 conector x1