diff options
Diffstat (limited to 'libraries/EEPROM/examples')
8 files changed, 370 insertions, 26 deletions
diff --git a/libraries/EEPROM/examples/eeprom_clear/eeprom_clear.ino b/libraries/EEPROM/examples/eeprom_clear/eeprom_clear.ino index b18ff2c..49eb5fe 100644 --- a/libraries/EEPROM/examples/eeprom_clear/eeprom_clear.ino +++ b/libraries/EEPROM/examples/eeprom_clear/eeprom_clear.ino @@ -2,22 +2,34 @@ * EEPROM Clear * * Sets all of the bytes of the EEPROM to 0. + * Please see eeprom_iteration for a more in depth + * look at how to traverse the EEPROM. + * * This example code is in the public domain. - */ #include <EEPROM.h> void setup() { - // write a 0 to all 512 bytes of the EEPROM - for (int i = 0; i < 512; i++) + + /*** + Iterate through each byte of the EEPROM storage. + + 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. + ***/ + + for ( int i = 0 ; i < EEPROM.length() ; i++ ) EEPROM.write(i, 0); // turn the LED on when we're done digitalWrite(13, HIGH); } -void loop() -{ -} +void loop(){ /** Empty loop. **/ } diff --git a/libraries/EEPROM/examples/eeprom_crc/eeprom_crc.ino b/libraries/EEPROM/examples/eeprom_crc/eeprom_crc.ino new file mode 100644 index 0000000..8461d56 --- /dev/null +++ b/libraries/EEPROM/examples/eeprom_crc/eeprom_crc.ino @@ -0,0 +1,50 @@ +/*** + Written by Christopher Andrews. + CRC algorithm generated by pycrc, MIT licence ( https://github.com/tpircher/pycrc ). + + A CRC is a simple way of checking whether data has changed or become corrupted. + This example calculates a CRC value directly on the EEPROM values. + The purpose of this example is to highlight how the EEPROM object can be used just like an array. +***/ + +#include <Arduino.h> +#include <EEPROM.h> + +void setup(){ + + //Start serial + Serial.begin(9600); + while (!Serial) { + ; // wait for serial port to connect. Needed for Leonardo only + } + + //Print length of data to run CRC on. + Serial.print( "EEPROM length: " ); + Serial.println( EEPROM.length() ); + + //Print the result of calling eeprom_crc() + Serial.print( "CRC32 of EEPROM data: 0x" ); + Serial.println( eeprom_crc(), HEX ); + Serial.print( "\n\nDone!" ); +} + +void loop(){ /* Empty loop */ } + +unsigned long eeprom_crc( void ){ + + const unsigned long crc_table[16] = { + 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, + 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, + 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, + 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c + }; + + unsigned long crc = ~0L; + + for( int index = 0 ; index < EEPROM.length() ; ++index ){ + crc = crc_table[( crc ^ EEPROM[index] ) & 0x0f] ^ (crc >> 4); + crc = crc_table[( crc ^ ( EEPROM[index] >> 4 )) & 0x0f] ^ (crc >> 4); + crc = ~crc; + } + return crc; +}
\ No newline at end of file diff --git a/libraries/EEPROM/examples/eeprom_get/eeprom_get.ino b/libraries/EEPROM/examples/eeprom_get/eeprom_get.ino new file mode 100644 index 0000000..6620999 --- /dev/null +++ b/libraries/EEPROM/examples/eeprom_get/eeprom_get.ino @@ -0,0 +1,66 @@ +/*** + eeprom_get example. + + This shows how to use the EEPROM.get() method. + + To pre-set the EEPROM data, run the example sketch eeprom_put. + This sketch will run without it, however, the values shown + will be shown from what ever is already on the EEPROM. + + This may cause the serial object to print out a large string + of garbage if there is no null character inside one of the strings + loaded. + + Written by Christopher Andrews 2015 + Released under MIT licence. +***/ + +#include <EEPROM.h> + +void setup(){ + + float f = 0.00f; //Variable to store data read from EEPROM. + int eeAddress = 0; //EEPROM address to start reading from + + Serial.begin( 9600 ); + while (!Serial) { + ; // wait for serial port to connect. Needed for Leonardo only + } + Serial.print( "Read float from EEPROM: " ); + + //Get the float data from the EEPROM at position 'eeAddress' + EEPROM.get( eeAddress, f ); + Serial.println( f, 3 ); //This may print 'ovf, nan' if the data inside the EEPROM is not a valid float. + + /*** + As get also returns a reference to 'f', you can use it inline. + E.g: Serial.print( EEPROM.get( eeAddress, f ) ); + ***/ + + /*** + Get can be used with custom structures too. + I have separated this into an extra function. + ***/ + + secondTest(); //Run the next test. +} + +struct MyObject{ + float field1; + byte field2; + char name[10]; +}; + +void secondTest(){ + int eeAddress = sizeof(float); //Move address to the next byte after float 'f'. + + MyObject customVar; //Variable to store custom object read from EEPROM. + EEPROM.get( eeAddress, customVar ); + + Serial.println( "Read custom object from EEPROM: " ); + Serial.println( customVar.field1 ); + Serial.println( customVar.field2 ); + Serial.println( customVar.name ); +} + +void loop(){ /* Empty loop */ }
\ No newline at end of file diff --git a/libraries/EEPROM/examples/eeprom_iteration/eeprom_iteration.ino b/libraries/EEPROM/examples/eeprom_iteration/eeprom_iteration.ino new file mode 100644 index 0000000..650c90a --- /dev/null +++ b/libraries/EEPROM/examples/eeprom_iteration/eeprom_iteration.ino @@ -0,0 +1,57 @@ +/*** + eeprom_iteration example. + + A set of example snippets highlighting the + simplest methods for traversing the EEPROM. + + Running this sketch is not necessary, this is + simply highlighting certain programming methods. + + Written by Christopher Andrews 2015 + Released under MIT licence. +***/ + +#include <EEPROM.h> + +void setup() { + + /*** + Iterate the EEPROM using a for loop. + ***/ + + for( int index = 0 ; index < EEPROM.length() ; index++ ){ + + //Add one to each cell in the EEPROM + EEPROM[ index ] += 1; + } + + /*** + Iterate the EEPROM using a while loop. + ***/ + + int index = 0; + + while( index < EEPROM.length() ){ + + //Add one to each cell in the EEPROM + EEPROM[ index ] += 1; + index++; + } + + /*** + Iterate the EEPROM using a do-while loop. + ***/ + + int idx = 0; //Used 'idx' to avoid name conflict with 'index' above. + + do{ + + //Add one to each cell in the EEPROM + EEPROM[ idx ] += 1; + idx++; + }while( idx < EEPROM.length() ); + + +} //End of setup function. + +void loop(){}
\ No newline at end of file diff --git a/libraries/EEPROM/examples/eeprom_put/eeprom_put.ino b/libraries/EEPROM/examples/eeprom_put/eeprom_put.ino new file mode 100644 index 0000000..186cf95 --- /dev/null +++ b/libraries/EEPROM/examples/eeprom_put/eeprom_put.ino @@ -0,0 +1,56 @@ +/*** + eeprom_put example. + + This shows how to use the EEPROM.put() method. + Also, this sketch will pre-set the EEPROM data for the + example sketch eeprom_get. + + Note, unlike the single byte version EEPROM.write(), + the put method will use update semantics. As in a byte + will only be written to the EEPROM if the data is actually + different. + + Written by Christopher Andrews 2015 + Released under MIT licence. +***/ + +#include <EEPROM.h> + +struct MyObject{ + float field1; + byte field2; + char name[10]; +}; + +void setup(){ + + Serial.begin(9600); + while (!Serial) { + ; // wait for serial port to connect. Needed for Leonardo only + } + + float f = 123.456f; //Variable to store in EEPROM. + int eeAddress = 0; //Location we want the data to be put. + + + //One simple call, with the address first and the object second. + EEPROM.put( eeAddress, f ); + + Serial.println("Written float data type!"); + + /** Put is designed for use with custom structures also. **/ + + //Data to store. + MyObject customVar = { + 3.14f, + 65, + "Working!" + }; + + eeAddress += sizeof(float); //Move address to the next byte after float 'f'. + + EEPROM.put( eeAddress, customVar ); + Serial.print( "Written custom data type! \n\nView the example sketch eeprom_get to see how you can retrieve the values!" ); +} + +void loop(){ /* Empty loop */ }
\ No newline at end of file diff --git a/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino b/libraries/EEPROM/examples/eeprom_read/eeprom_read.ino index ebf79d6..68c4ffc 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 + /*** + 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. + ***/ 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) + if(address == EEPROM.length()) address = 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. + + ++address &= EEPROM.length() - 1; + ***/ delay(500); } diff --git a/libraries/EEPROM/examples/eeprom_update/eeprom_update.ino b/libraries/EEPROM/examples/eeprom_update/eeprom_update.ino new file mode 100644 index 0000000..831056f --- /dev/null +++ b/libraries/EEPROM/examples/eeprom_update/eeprom_update.ino @@ -0,0 +1,69 @@ +/*** + EEPROM Update method + + Stores values read from analog input 0 into the EEPROM. + These values will stay in the EEPROM when the board is + turned off and may be retrieved later by another sketch. + + If a value has not changed in the EEPROM, it is not overwritten + which would reduce the life span of the EEPROM unnecessarily. + + Released using MIT licence. + ***/ + +#include <EEPROM.h> + +/** the current address in the EEPROM (i.e. which byte we're going to write to next) **/ +int address = 0; + +void setup(){ /** EMpty setup **/ } + +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; + + /*** + Update the particular EEPROM cell. + these values will remain there when the board is + turned off. + ***/ + EEPROM.update(address, val); + + /*** + The function EEPROM.update(address, val) is equivalent to the following: + + if( EEPROM.read(address) != val ){ + EEPROM.write(address, val); + } + ***/ + + + /*** + 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. + ***/ + address = address + 1; + if(address == EEPROM.length()) + address = 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. + + ++address &= EEPROM.length() - 1; + ***/ + + delay(100); +} diff --git a/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino b/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino index c047887..f07446c 100644 --- a/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino +++ b/libraries/EEPROM/examples/eeprom_write/eeprom_write.ino @@ -8,31 +8,51 @@ #include <EEPROM.h> -// the current address in the EEPROM (i.e. which byte -// we're going to write to next) -int addr = 0; +/** the current address in the EEPROM (i.e. which byte we're going to write to next) **/ +int addr = 0; -void setup() -{ -} +void setup(){ /** Empty setup. **/} 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. + /*** + 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; - // write the value to the appropriate byte of the EEPROM. - // these values will remain there when the board is - // turned off. + /*** + Write the value to the appropriate byte of the EEPROM. + these values will remain there when the board is + turned off. + ***/ + EEPROM.write(addr, val); - // advance to the next address. there are 512 bytes in - // the EEPROM, so go back to 0 when we hit 512. + /*** + 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 == 512) + 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(100); } |