Ultrasonic sensor comparison: HC-SR04, PING, Maxbotix

For many projects You will need to measure distance, let’s say You are building a robot and You don’t want to have it bouncing on the walls, aren’t You? One of the first ideas to get some orientation in surroundings is to use ultrasonic range sensor. We took three different sensors and do some basic […]

Logging and converting float values to Strings on Arduino

In Arduino You can use String class, which can be used to create log messages. Often You need to add some numeric values in this messages. It can be simple as that code:   String cmd = “curl –data \”key=”+key;   for (int i=0;i<ARRAY_SIZE;i++) {     cmd = cmd + “&field”+ (i+1) + “=” + value[i];   }   cmd = cmd + “\” http://api.thingspeak.com/update”; You may recognize […]

Project: Using Arduino YUN to control things remotely

Arduino YUN is very interesting product. Mixing OpenWRT and Arduino in one board is effective. OpenWRT does things related to WiFi connectivity, Arduino YUN does interact with physical world, and standard Arduino library makes connecting both parts easy. Now we need some simple project to demonstrate how You can control things remotely with Arduino YUN […]

Arduino as ISP or how to burn bootloader

Often You need burn bootloader onto ATmega chip. You can always buy chip with preloaded bootloader or ISP programmer like USBASP, however any working Arduino can be used as one. You can do as follows: download ArduinoISP sketch in working Arduino (menu File/Examples/ArduinoISP) as any other sketch connect chip in following way (on right are […]

P4A – PHP for Arduino part 2

In the previous post we’ve finished with reading files from SD card. Now we have to pass them through our PHP :) and send the results to the client. To make whole process more simple, we’re assuming each of the files is known to us. This means, we’re registering every file (URL) with addCommand. How […]

P4A – PHP for Arduino part 1

If you already know Arduino stuff a bit, maybe you want to connect it with a network somehow. It could be some network-enabled home automation solution or a set of sensors sending data to a database. So, here comes the Ethernet Shield to help you. First, a bit of history. Initially, the Ethernet Shield was […]