I just published the minimal version of the data logger project. The minimal version uses the built-in EEPROM of the microcontroller to log sensor data. I decided to create this additional minimal version because it works for very simple cases and does not need any external memory.
The data logging mode is controlled using a BCD DIL switch. Using this switch you can select logging mode, read mode and format mode.
The documentation is explaining how to create this data logger in detail. All about the parts, how to build the hardware, how to build the software and a detailed page which explains the software in detail. There is also a short overview of the project and how to use the final device.
Start reading the detailed documentation here:
If you have any questions or feedback about this project, feel free to leave comments on these pages.