Eye catching LED ring display

There is always a dilemma on how to build an indicator for your next project. There are many options like LCDs, LEDs, VFD. Sometimes one or another is enough, but eventually you want something eye catching and obvious that could be seen from distance. For instance for water meter a dial based display probably is better than LCD. IT can be seen from distance and is informative to tell how mutch water is in tank. John simply built a LED ring display out of 16 single color LEDs. He needed to use shift register, but he thought that popular 74xx595 chip is very current limited. Total current draw shouldn’t exceed 50mA which is like 2 more powerful LEDs at a time. So he looked for more proper shift register and came op with better one – TLC59282 16-bit shift register which is capable of sinking 30mA on each pin. Neat feature of this chip is that it comes with current setting pin, meaning that you only need single resistor for setting current for all LEDs. This saves space on the… Continue reading

Xylophone plays itself

This is completely home made xylophone made with CNC milling machine. But to be it completely awesome Nerdkits have made it automatic by adding also home made solenoids that actuate each sound by hammering bars with bolt head. They made xylophone universal that could be interfaced to any microcontroller board. It accepts serial data stream that is paralleled with shift register. This way you need 3 MCU pins to drive eight solenoids. And of course shift register is an additional protection of MCU from solenoids. There is a simple example program playing tunes with Atmega168 microcontroller. Continue reading

Arduino Nano with Marcel MM5450 and 8×8 LED matrix

Microcontroller is a very special and useful electronic device, as it equips with many incredible features and makes the electronic projects become easier! However, once you’re dealing with a microcontroller, you might having difficulty – You couldn’t have the enough pins to perform the jobs. Well, you might have the option here: Choose to move up to a hundred pins microcontroller and the problem is solved up immediately! However, your wallet is heavily burnt up, as you need to pay an enormous price for the chip. Or, you would prefer to pass off the IO complexity to another chip. In this case, the amazing combination – Arduino Nano board with Marcel MM5450 and 8×8 LED matrix. Basically, this device is an LED driver that works as a travel log, or a “Shift Register”. For your information, there are 25 pins outputs, where each of the outputs can provide up to 15mA! In addition, it has a communication protocol that allows easy control with only two pins. By using the device, you can easily test out the simple text scroller and… Continue reading