Storing Data: EEPROM, SD Cards and File Formats

10 Lektionen in dieser Stufe

1. Internal EEPROM: Bytes That Survive Power Loss
   Read and write single bytes of the ATmega328P's 1 kB non-volatile memory. · Lab: Count power-ups in EEPROM and display the count at each start.
2. Storing Structs with EEPROM.put and EEPROM.get
   Save and restore whole settings records in one call. · Lab: Store brightness, interval and a name and reload them at start-up.
3. Write Endurance and Wear-Reducing Strategies
   Respect the limited number of write cycles and write only when needed. · Lab: Compare write counts of naive saving with update-on-change and delayed saving.
4. Validating Stored Settings with a Version Byte and CRC
   Detect blank, outdated or corrupted data and fall back to defaults. · Lab: Add a version and CRC to the settings block and corrupt one byte to test recovery.
5. microSD Cards: Wiring, Voltage and FAT Formatting
   Connect a card module safely and prepare a card the library can read. · Lab: Initialise the card and print its type and size.
6. Creating, Appending and Reading Files
   Open files in the right mode and close them properly. · Lab: Write lines to a file, read them back and list the card's directory.
7. CSV Logging with Real-Time Clock Timestamps
   Produce spreadsheet-ready files with a header and ISO timestamps. · Lab: Log temperature, humidity and pressure every ten seconds and open the file in a spreadsheet.
8. Surviving Power Cuts: Flush Intervals and File Rotation
   Limit data loss on sudden power-off and keep files small by rotating them daily. · Lab: Pull power during logging and check how much data survived with different flush settings.
9. Reading Configuration Files from the Card
   Parse simple key and value text so users can change settings without reprogramming. · Lab: Read logging interval and device name from a config file with defaults for missing keys.
10. External I2C EEPROM and FRAM for Larger Data
    Add non-volatile memory beyond the internal 1 kB and compare endurance and speed. · Lab: Write and verify a 1 kB block on both chips and time the operations.

Abschlussprojekt

A stand-alone environmental data logger with timestamped CSV files, a validated settings block and safe behaviour on power loss.

Teile für diese Stufe

• 1 × UNO-compatible board
• 1 × USB cable matching the board
• 1 × Solderless breadboard 830 points
• 1 × Jumper wire set male-male and male-female
• 1 × microSD card module with level shifting
• 1 × microSD card 8–32 GB
• 1 × DS3231 real-time clock module with battery
• 1 × BME280 pressure, humidity and temperature module
• 1 × I2C EEPROM module 24LC256
• 1 × I2C FRAM module
• 2 × Tactile push button
• 2 × LED 5 mm assorted
• 2 × Resistor 220 ohm
• 1 × OLED display 0.96 inch I2C 128x64

In jeder Lektion legst du die passenden Teile direkt in den Warenkorb. Arduino-kompatibel →