Eeprom usage

[pawel]

Hi.
How mySensors usage eeprom memory?
How many bytes and with addresses?
I would like use eeprom memory to own application but I don't know with address will be free.

Thx.
Pawel

[hek]

You'll find the addresses used here:
https://github.com/mysensors/Arduino/blob/master/libraries/MySensors/MySensor.h#L44

If you only need 256 bytes you can use the library functions saveState()/loadState() which makes sure you won't mess up anything.

[marcusvdt]

@hek I have a quick question regarding the gw.saveState and consequently the gw.loadState instructions
As per the link and code you have mentioned, reproduced below:

// EEPROM start address for mysensors library data
#define EEPROM_START 0
// EEPROM location of node id
#define EEPROM_NODE_ID_ADDRESS EEPROM_START
// EEPROM location of parent id
#define EEPROM_PARENT_NODE_ID_ADDRESS (EEPROM_START+1)
// EEPROM location of distance to gateway
#define EEPROM_DISTANCE_ADDRESS (EEPROM_PARENT_NODE_ID_ADDRESS+1)
#define EEPROM_ROUTES_ADDRESS (EEPROM_DISTANCE_ADDRESS+1) // Where to start storing routing information in EEPROM. Will allocate 256 bytes.
#define EEPROM_CONTROLLER_CONFIG_ADDRESS (EEPROM_ROUTES_ADDRESS+256) // Location of controller sent configuration (we allow one payload of config data from controller)
#define EEPROM_FIRMWARE_TYPE_ADDRESS (EEPROM_CONTROLLER_CONFIG_ADDRESS+24)
#define EEPROM_FIRMWARE_VERSION_ADDRESS (EEPROM_FIRMWARE_TYPE_ADDRESS+2)
#define EEPROM_FIRMWARE_BLOCKS_ADDRESS (EEPROM_FIRMWARE_VERSION_ADDRESS+2)
#define EEPROM_FIRMWARE_CRC_ADDRESS (EEPROM_FIRMWARE_BLOCKS_ADDRESS+2)
#define EEPROM_LOCAL_CONFIG_ADDRESS (EEPROM_FIRMWARE_CRC_ADDRESS+2) // First free address for sketch static configuration

I understand it translates to:

ADDRESS	SIZE		ALIAS
0X000	1 BYTE		EEPROM_START, EEPROM_NODE_ID_ADDRESS
0X001	1 BYTE		EEPROM_PARENT_NODE_ID_ADDRESS
0X002	1 BYTE		EEPROM_DISTANCE_ADDRESS
0X003	256 BYTES		EEPROM_ROUTES_ADDRESS
0X103	24 BYTES	EEPROM_CONTROLLER_CONFIG_ADDRESS
0X11B	2 BYTES		EEPROM_FIRMWARE_TYPE_ADDRESS
0X11D	2 BYTES		EEPROM_FIRMWARE_VERSION_ADDRESS
0X11F	2 BYTES		EEPROM_FIRMWARE_BLOCKS_ADDRESS
0X121	2 BYTES		EEPROM_FIRMWARE_CRC_ADDRESS
0X123	???			EEPROM_LOCAL_CONFIG_ADDRESS

So it means when I perform these instructions:
lightStatus = state;
gw.saveState(0,state);

In what specific address am I saving the data? The instruction itself says position zero, so am I saving to the first address 0x123 in this case???

Thanks in advance.

[hek]

0x123

Yes, that sounds about right.

[bisschopsr]

Sound good! How can I write/read values over 255 to the EEPROM. This takes more then one byte.
If I write 255, I get: 255 0 (place 0 place 1)
256 will give: 0 255
257 will give: 1 255
etc.

Reading only reads the byte indicated with the function loadState()

Thanks in advance

Ralph

[fets]

@bisschopsr I think you can use hw_writeConfigBlock/hw_readConfigBlock with the "right" address

[bisschopsr]

Hi All,

Resolved this with a simple funtion splitting the value in byte long parts. Bit shifting and OR are a perfect fit for this :-).

The code:

void storeEeprom(int pos, int value) {
	// function for saving the values to the internal EEPROM
	// value = the value to be stored (as int)
	// pos = the first byte position to store the value in
	// only two bytes can be stored with this function (max 32.767)
	gw.saveState(pos, ((unsigned int)value >> 8 ));
	pos++;
	gw.saveState(pos, (value & 0xff));
}

int readEeprom(int pos) {
	// function for reading the values from the internal EEPROM
	// pos = the first byte position to read the value from 

	int hiByte;
	int loByte;

	hiByte = gw.loadState(pos) << 8;
	pos++;
	loByte = gw.loadState(pos);
	return (hiByte | loByte);
}