What is it?

One wire programmer, which can be used to read the stored data and to write additional data in "One Wire" EEPROMS, Sensors , etc. chips. It is based on Arduino Leonardo ver.3, on which additional functionality is added. The device has installed bootloader. It generates on board the 12 V voltage needed for the programming of the EEPROM and can automatically apply the voltage under request at the One wire bus. Of course it can be used also as standard Arduino Leonardo board with taking into account the additional functionality of the digital pins 6 and 7.

Why did you make it?

I had a Dell laptop charger, which I replaced with universal one, but it was not working because of the Dells chargers comparability check. This check is performed by the use of one wire EEPROM installed in the charger. This chip communicates with the laptop and sends unique digital signature. To overcome the problem I needed a programmer to write the correct signature in a empty DS2501 EEPROM chip. Such programmers is difficult to find on the market and they are very expensive. I decided to design my own programmer. That programmer also has to be multi-functional - so I decided the base the design over Arduino board keeping its main functionality.

What makes it special?

Arduino Leonardo with embedded one wire programmer, which can not only read data from one wire devices, but it can also write data to them without use of any additional circuitry or shields. The programmer uses the Standard "OneWire" Arduino library. As one wire data pin is used the Arduino digital pin 7. The 12 V programming voltage is enabled by forcing the digital pin 6 LOW. In the Arduino sketch, in the setup section, the following two lines should be included :

pinMode(6, OUTPUT); digitalWrite(6, HIGH);

When the data is loaded in and have to be stored permanently - the pin 6 is forced LOW for the programming time defined in the EEPROM datasheet.