diff options
Diffstat (limited to 'libraries/EEPROM/examples/eeprom_write')
| -rw-r--r-- | libraries/EEPROM/examples/eeprom_write/eeprom_write.ino | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino b/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino index f07446c..f9bea64 100644 --- a/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino +++ b/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino @@ -9,18 +9,19 @@ #include <EEPROM.h> /** the current address in the EEPROM (i.e. which byte we're going to write to next) **/ -int addr = 0; +int addr = 0; -void setup(){ /** Empty setup. **/} +void setup() { + /** Empty setup. **/ +} -void loop() -{ +void loop() { /*** Need to divide by 4 because analog inputs range from 0 to 1023 and each byte of the EEPROM can only hold a value from 0 to 255. ***/ - + int val = analogRead(0) / 4; /*** @@ -28,28 +29,29 @@ void loop() these values will remain there when the board is turned off. ***/ - + EEPROM.write(addr, val); /*** - Advance to the next address, when at the end restart at the beginning. - + Advance to the next address, when at the end restart at the beginning. + Larger AVR processors have larger EEPROM sizes, E.g: - Arduno Duemilanove: 512b EEPROM storage. - Arduino Uno: 1kb EEPROM storage. - Arduino Mega: 4kb EEPROM storage. - + Rather than hard-coding the length, you should use the pre-provided length function. - This will make your code portable to all AVR processors. + This will make your code portable to all AVR processors. ***/ addr = addr + 1; - if(addr == EEPROM.length()) + if (addr == EEPROM.length()) { addr = 0; - + } + /*** - As the EEPROM sizes are powers of two, wrapping (preventing overflow) of an + As the EEPROM sizes are powers of two, wrapping (preventing overflow) of an EEPROM address is also doable by a bitwise and of the length - 1. - + ++addr &= EEPROM.length() - 1; ***/ |