Lupin's weblog

I wired up a DS1621 digital thermometer IC to the PM. With this IC it’s possible to measure the temperature very easily.

I communicate with the sensor using the same I²C bus functions as for EEPROM access (just one small additional function). The sensor outputs the temperature as 9 bits of data.

The black IC in front is wired to the PM using magnet wire.

My cheap clock/thermometer agrees with the DS1621.

Included in the zip file are instructions to wire up the sensor to the PM, so you can add a temperature sensor to your PM too (and read the temperature if you’ve got a flashcart ).

I wrote some I²C functions for the PM, they can be used to access the savestate EEPROM. The functions should be quite easy to use. I uploaded a sample of writing a few bytes to the EEPROM and reading them back. You can find it in the PM section.

PlayerOne discovered how to read from the EEPROM, the website of the Embedded Systems Academy had some useful informations to implement the functions like it’s specified by the I²C protocol.

Download the example.