I have been drooling over the Amtel’s ATtiny84 mcu ever since JCW released the JeeNode Micro few months ago. It is an amazing piece of art, you can basically have a single-chip micro controller that can do most of the tasks an Arduino can, it even has a in-built oscillator and can run at 8Mhz. Sweet. Then I saw Nathan Chantrell’s article on building a remote temperature sensor using this same mcu and could not resist getting one myself. It would be a nice addition to my emoncms, so I was ordering a ATtiny84, a TMP36 and a RFM12B the next minute. In the mean time, I was getting ready for it by installing the necessary patches to the Arduino IDE to get it working with this mcu. I own a tinyUSB ISP programmer already, so I didn’t need to worry about programming the chip with an Arduino. So once I got the parts, I follwed strictly Nathan’s instructuions and couple hours later I had a remote temperature sensor that sends data to my emoncms every minute.
Here are some pictures
I am tempted to create a PCB for this project and power it from a coin cell battery, lest see how this will go. There is a I2C protocol library available for this mcu so I may expand the project with a I2C port so I may become a remote “anything” sensor given that you have I2C sensors for almost anything you can think of.
Let me know if you would be interested in such sensor PCB and that may become my next hobby project 🙂