From 26577474efcb8874dad687467a8ba2f01678ff4c Mon Sep 17 00:00:00 2001 From: Chris--A Date: Fri, 20 Mar 2015 12:06:20 +1000 Subject: Updated EEPROM examples. Removed hard coded lengths, which were incorrect for standard Arduino's now. --- .../EEPROM/examples/eeprom_read/eeprom_read.ino | 28 ++++++++++++++++------ 1 file changed, 21 insertions(+), 7 deletions(-) (limited to 'libraries/EEPROM/examples/eeprom_read') diff --git a/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino b/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino index ebf79d6..8567ed7 100644 --- a/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino +++ b/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino @@ -31,13 +31,27 @@ void loop() Serial.print(value, DEC); Serial.println(); - // advance to the next address of the EEPROM - address = address + 1; - - // there are only 512 bytes of EEPROM, from 0 to 511, so if we're - // on address 512, wrap around to address 0 - if (address == 512) - address = 0; + /*** + 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. + ***/ + addr = addr + 1; + if(addr == EEPROM.length()) + addr = 0; + + /*** + 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; + ***/ delay(500); } -- cgit v1.2.3-18-g5258