Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Building microphone preamp for microcontroller analog input

Microphone is another analog signal sensor which converts sound wave energy into electrical signal. Some microphones does this directly (dynamic microphones), some need additional electrical source like electret. Electret microphone is simply a capacitor which one moving diaphragm which by moving changes capacitance. It can be captured with simple RC circuit. But the signal is very low and barely detectable with microcontroller ADC. This is why normally there are microphone preamp used that gains microphone signal, filters it and gives a DC offset so it would fir perfectly to full rail of ADC input. David actually have made two iterations of microphone preamp circuits. Previous was NPN transistor based which performed pretty good, but this time he wanted to bet even better signal and so he used operational amplifier. He selected TLC272 opamp which can work from single rail and down to 3V which makes it ideal choice for 5V and 3.3V microcontroller circuits. He found that this circuit performs pretty good even on low sound and produces lower noise than NPN version. Bellow you can see how he tested… Continue reading

DIY 3D Controller is as easy as ABC!

The global recession has given a very deep impact to everyone. Go figure, there are millions of innocent people lost their jobs, either they’re being fired with or without reasonable excuses. Life is tough, especially for those who cannot find the suitable job after a long period! If you’re one of the unfortunate and you got the talent in DIY stuffs, then this is the perfect moment to show off your ability! Let’s have a closer look on the 3D Controller, the main purpose of this project is to make a 3D hand-position sensing system and preserve some semblance of functionality. Those components that you’re needed are: Arduino Processing Wire cutters Soldering iron Box cutter Three 270k resistors Three 10k resistors Solder Wire Aluminium foil Cardboard Scotch tape Shielded wire Three alligator clips 3-pin header Zip-tie Hot glue By the way, you also can modify this 3D Controller by applying some cool features on it, such as: Build massive sensors; You can try to optimize the resistors and code for things that vibrate quickly; You can transform it into a… Continue reading