USB accelerometer sensor, tilt sensor

Nowadays everyone has accelerometer sensor in its own smartphone. It’s there for several reasons. First of all it’s used for detection of screen orientation relative to the gravity field. This is the sensor which gives your phone information when the screen should be switched from landscape mode to portrait. Beside this there are many other ideas how to use accelerometer. One of them is pedometer. An app or device which uses accelerometer to track your steps. Read more…

How to chose resistor for LED diode

LED diodes are non linear elements whom I-V characteristic depend from many external parameters such as temperature and manufacture. Mathematically I(U) dependence is described by Shockley diode equation. Unfortunately this exponential dependence, after adding resistor in series, becomes implicit function of current and supply voltage witch can be only solve numerically. That is why we have to simplify things for practical purposes. Here is useful table witch I use for fast choice of resistor for Read more…