TV-B_Gone is another fun DIY microcontroller project. It's a simple remote control for TV that has function only Turn Off. So, there is only one button, power button. No Longer dumb advertisemsent on your TV, just use this cool microcontroller project to switch it off.
You can get this device on the market. But if you want to build it by yourself there are good news for you. Lady Ada an Mitch has build an open source version of the TV-B-Gone. it means you can download the schematic and the layout based on open source license.
How does it work?
If you hit the button it plays simply every shut down code stored in microcontroller and send it out to IR led. The transistors are used to drive a stronger current through the IR-LEDs. The latest TV-B-Gone kit have a range of about 50 meters. For the power supply you can use two battery AA.
Guitar is one of the most favourite music instrument. To get great sound you need to tune it first. There are many guitar tuner based on electronic circuit that can be use to tune guitar easily. One of them is Digital Guitar Tuner using microcontroller AVR Atmel 2323 created by Jesper.
"This microcontroller project is a simple, but accurate for Digital Guitar Tuner. It samples the input, which can be directly from the mics of an electric guitar, or from a microphone, it you're using an acoustic guitar. The circuit also can be used for tuning other instruments."
The samples are then checked against stored values for the strings, and the two LED's will show the tuning status - "Too Low", "Too High" or "In Tune" when both LED's are lit. The tuner will automatically switch between the six strings. The circuit is pretty simple. A small transistor amp pumps up the input signal to something the AVR can see on it's input pin. The other two I/O pins are used for driving the LED's. The input sensivity is around 50-60 mV. This gives a 2-3 V swing on the input pin, enough for the 2323 to read this as high and low levels.
If you interest to build this project, you can download the document, source code, schematic here (zip file)
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Is it possible to use DRAM with microcontroller AVR? Yes, it is possible. Jesperh has proved it. He hooked up a DRAM to a small processor (in this case an Microcontroller Atmel 8515), and handle the RAS/CAS sequencing and refresh in software. The type of DRAM is Hitatchi M5M44800, a 512k*8 DRAM!. Bigger than the original memory of microcontroller AT90S8515 that is 512 byte RAM. The project use C to programm it. The chip required small power consumption, only takes about 2-3 mA when just refreshing and with a low access rate.
But, the consequency is it will be relatively slow and put some extra load on the CPU, but if you need a cheap, large RAM memory and can accept the overhead, this is the way to go. But, with more bigger memory you get. It would not to bad to try isn't.
If you need source code, schematic, and documentatiaon about this microcontroller project click here (zip).
Another project by jesper
1. AVR digital counter
2. Temperature Controller
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