Monthly Archives: September 2012

Square wave generator and capacitance meter with IC 555

Hello, today I will explain how to make two simple circuits with the integrated 555.


To make a square wave generator we only need a couple of resistors, a capacitor of 0.01µF and another capacitor wich value we will to determine according to the characteristics that we want to our circuit have, to do it we have to apply the following formula.

Continue reading

Distance measuring with the module US-100 or HC-SR04 for Arduino (p2)

Hello, I will explain how to do a simple alarm with the program of the previous post, this alarm will sound when the measured value drops bellow a threshold that will set with a potentiometer.

To use the ultrasonic sensor as an alarm, wich is activated when the distance falls below a certain threshold set by a potentiometer, we will add to the circuit in the previous post a piezo speaker and a potentiometer.

The connections are as follows:

Continue reading

How to read data from Arduino to Matlab through serial port

Hello, in this post I will explain how to read in Matlab data received with Arduino through the USB port.

To explain how to read the data from our Arduino in Matlab I have relied on the project: “Distance measuring with the module US-100 or HC-SR04 for Arduino”, once loaded into our Arduino we can run the Matlab code described below:

Continue reading

Distance measuring with the module US-100 or HC-SR04 for Arduino (p1)

Hello, the other day I mount this simple circuit to test a sensor to measure distances by ultrasound recently purchased. For this project we will need the following items:

A protoboard.

An Arduino (In my case Arduino UNO).

An ultrasonic sensor module US-100 or HC-RS04 (I don’t know if there are other similar ultrasound modules).

An LCD display.

Two potentiometers.

A few wires.

We must ensure that we remove the jumper from the ultrasound module that is placed on pins “UART Select”, once done do the following assembly:

Continue reading