Purpose: Log data from a sensor in an SD card, and use a hashing function to create a unique signature of the data log and prevent any tampering with existing data.
Parts:
- Arduino Uno
- DHT11 temperature and humidity sensor
- SD card reader
- HC05 bluetooth connector (not included in program yet)
Schematics: I will provide schematics diagram later but for now: - Connect SD card reader CS pin to Arduino/10 - Connect DHT11 signal pin to Arduino/2
Dependencies:
- Sha1 library:
- I am using this library: https://github.com/Cathedrow/Cryptosuite.
- Installation: Make a 'libraries' directory with your Arduino sketches folder if you do not already have one. Copy the 'Sha' directory into that directory. Restart Arduino to rescan for new libraries.
- I found some issues when using the library at first due to some deprecations. I made small changes and included the new version in this project.
- SD library
- DHT library
Known issues:
- the program currently fails after several iterations. This is likely due to abusive use of String and string operations, and cluttering of the Heap memory. I am curerrntly working on a refactoring of the code using functions to move memory to the Stack and char instead of String.