Welcome back to Part 4, we now get to see some results of our work . The video below shows the ATtiny85 running at 5 volts with our standalone temperature logger software and retrieving the data from the ATtiny’s EEPROM and printing it on our computer screen.
Why did I mention “ATtiny85 running at 5 volts”? It’s because we aren’t quite done yet with this project, the next step which is Part 5 is to adjust our code and schematic to run the ATtiny85 on 2 AA batteries. Then after that we need to make a PCB of it!
Lets begin with Part 3 in which I’ll hook up the ATtiny85, program the simple LED blinking test, take it away from the Arduino, run it on a 9V battery and also how we are actually using the thermistor to calculate the temperature.
Firstly we’ll visit the website I gave in the first part, which shows us how to hook up the ATtiny85 to the Arduino so the Arduino can program it. Here is a mirror of the site and download files in case it’s down: HLT wiki Arduino A Ttiny 4585_files
We choose from the Arduino program to open up the ArduinoISP sketch which is below the “8. Strings” selection. Now just upload that to your Arduino.
Welcome to Part 2, here we’ll test our implemented code out on the Arduino for a proof of concept. As you’ll recall the Standalone Temperature Logger’s function is to record temperature every x minutes defined by the user and log this to the EEPROM.
The code is fairly simple and will be explained in this post. What hasn’t been coded is my implementation of a simpler 2 Wire protocol as this actually requires an ATtiny85, so I’d like to make sure the code is functional before continuing.
I plan to build a Standalone Temperature Logger with the minimum components as I can, I’ll be using the ATtiny85 and Arduino software to program it. Firstly I’ll have it run on the Arduino to confirm it’s working, then migrate it to the ATtiny85, make it run on battery and make a PCB of it all. It sounds like a simple concept, but I know there’s going to be more to it that meets the eye.
Use the minimum components possible
Power the project with batteries
Specify the logging delay time
Write temperature to EEPROM on-board
How to extract data from EEPROM
Now lets go through all these design characteristics.