GPS for accurate synchronization and position measurement must use precise clock, so GPS satellites are equipped with atomic clocks. Clock accuracy is amazing ± 1 second in 1 million years. Using GPS module is available not only acquire position, speed, bet also time and date, so in this post I’ll explain how to do it.
Sirf II module has RS-232 interface for communication and it can be connected to PC Com port. Atmega in Arduino board has UART interface. RS-232 basically is the same UART, only zeros and ones voltage levels are different. To match levels MAX232 driver is used. Today’s GPS modules have UART port, so there isn’t any need for MAX232.
Arduino GPS clock using NMEA protocol - [Link]
Old wish to make digitally controlled FM tuner come true when I found on Ebay cheap module with TEA5767 (Low-power FM stereo radio for handheld applications).
This module size is only 11.2mm x 11mm. TEA 5767 supports I2C.
For antenna i have used just 75 cm long wire, because that is 1/4 of wavelength at 100 MHz. TEA5767 doesn’t have audio amplifier, sound output level is very low, headphone can not be connected directly. During testing i had connected audio output to PC audio system.
Arduino FM receiver with TEA5767 - [Link]
LCD in this picture has 2×16 characters, so in quick way horizontal bar could have 16 steps resolution, but it’s not enough. Each character is formed from 5×8 pixels. Every character can be sliced in to 5 pieces. After that we can have 5*16 = 80 steps. First step is to create 5 custom characters. More about createChar() please read at arduino.cc.
Arduino LCD horizontal progress bar using custom characters - [Link]
This is a very simple capacity tester. It consists of single resistor that discharges battery. Arduino measures the voltage drop across resistor. According to Ohm’s Law current = voltage/resistance. Every second value of current is divided by 3600 and summed up to get the capacity expressed in Ah (Amp per hour).
I have used two parallel connected resistors that total resistance is 6.9 ohm. Make sure that they have proper power rating, if you don’t want them to convert to smoke. If voltage across 6.9 ohm resistor is 3.7 V, then current – 0.54 A, power ~ 2W.
Arduino Lithium-ion battery capacity tester/discharge monitor - [Link]
Did you know each Arduino has a unique serial number in its USB interface that you can use to distinguish one Arduino from another? If you deal with multiple Arduinos, knowing exactly which one is plugged into your computer can be a real time-saver. But actually getting at this serial number and mapping it to COM ports can be challenging. For Windows computers, here’s “listComPorts”, implemented both in GCC C code and in VBScript, both available from my usbSearch github repository.
listComPorts – Windows command-line tool for USB-to-serial - [Link]
I was looking for, what I thought, was a simple clock/timer design. Something with a remote and a big display that could be read from across the gym and that I could program with up/down counting but also intervals specific to CrossFit like Fight Gone Bad or tabatas. I wanted to incorporate a bell to give it a gym feel and something that could be heard over loud music. This journey took me through many designs, chips, a custom board, wood working and a whole lot of learning!
Arduino CrossFit Timer - [Link]
Luca explains how to boot your PC with a Wake on Lan command sent from an Arduino. Setup the WOL feature on your PC, then use the sendWOL() command to send a magic packet via and ENC28J60 ethernet chip: [via]
The wake command is issued sending on the network a specific packet, called Magic Packet. This packet is receved by all the devices connected to local network because it presents – as destination MAC address – the broadcast address (FF:FF:FF:FF:FF:FF). It includes six bytes valued FF, followed by the target PC’s MAC address repeated 16 times.
Boot your PC with the Arduino using the Wake on Lan command - [Link]
We want to show you how to use the popular Arduino to produce a device capable of recognizing passive transponder (TAG). But this is not the usual RFID key, because the system can activate a relay if a recognised TAG is read, but also we took the opportunity to make an application that use cloud-computing. The basic version, which is a simple key relay consists of an Arduino and the RFID shield based on a ID-12 of Innovations: placing a transponder already learned, the relay is activated. The extended version of our project uses an Arduino, the RFID Shield and the Ethernet Shield with which we can access the Internet and stored, using the Google Docs service, the transponder data.
Arduino RFID shield on the Cloud - [Link]
A lot of people who bought the TiDiGino ask me how to test it. The Gsm Remote Control is provided with bootloader, so you have to insert the prefered sketch that you can find in code.google. Daniele Denaro wrote a good sketch for TiDiGino, and I’m reporting his tutorial. Ask me (and him) all do you need.
Author Daniele Denaro
Be careful, because you have to manipulate the environment of development (IDE) 1.0 to insert the new hardware. In particular replace the file “boards.txt” (see below). In this new version of the file has been added to the section on hardware TiDiGino. You should also add the folder “tidigino” that “boards.txt” references (see below). The changes will be visible to restart the IDE.
Software and firmware for TiDiGino - [Link]
Kerry uses a DIY serial display to show debugging data sent from an Arduino’s UART. Sometimes the data comes too fast to read, so he added a 4K buffer and controls to scroll thorough the history. [via]
…if your application generates a lot of messages, it would still be hard to spot the relevant information as you can only see the last couple of lines of the data.
So my solution is to add a none-volatile off-screen buffer to the serial display so that multiple rows of data can be captured during run time and retained for later debugging.
Serial port monitor with 2×20 LCD and 4K text buffer - [Link]