I2C eeprom write fix for SAMD (#786)

* I2C eeprom write fix for samd

* Implement extEEPROM library for SAMD

core/MyHwSAMD.cpp

@@ -41,62 +41,30 @@ ISR (WDT_vect)
 */
 
 
-
-void i2c_eeprom_write_byte(unsigned int eeaddress, byte data )
-{
-	int rdata = data;
-	Wire.beginTransmission(I2C_EEP_ADDRESS);
-	Wire.write((int)(eeaddress >> 8)); // MSB
-	Wire.write((int)(eeaddress & 0xFF)); // LSB
-	Wire.write(rdata);
-	Wire.endTransmission();
-}
-
-byte i2c_eeprom_read_byte(unsigned int eeaddress )
-{
-	byte rdata = 0xFF;
-	Wire.beginTransmission(I2C_EEP_ADDRESS);
-	Wire.write((int)(eeaddress >> 8)); // MSB
-	Wire.write((int)(eeaddress & 0xFF)); // LSB
-	Wire.endTransmission();
-	Wire.requestFrom(I2C_EEP_ADDRESS,1);
-	if (Wire.available()) {
-		rdata = Wire.read();
-	}
-	return rdata;
-}
-
 void hwReadConfigBlock(void* buf, void* adr, size_t length)
 {
 	uint8_t* dst = static_cast<uint8_t*>(buf);
-	int offs = reinterpret_cast<int>(adr);
-	while (length-- > 0) {
-		*dst++ = i2c_eeprom_read_byte(offs++);
-	}
+	const int offs = reinterpret_cast<int>(adr);
+	(void)eep.read(offs, dst, length);
+
 }
 
 void hwWriteConfigBlock(void* buf, void* adr, size_t length)
 {
 	uint8_t* src = static_cast<uint8_t*>(buf);
-	int offs = reinterpret_cast<int>(adr);
-	while (length-- > 0) {
-		i2c_eeprom_write_byte(offs++, *src++);
-	}
+	const int offs = reinterpret_cast<int>(adr);
+	// use update() instead of write() to reduce e2p wear off
+	(void)eep.update(offs, src, length);
 }
 
 uint8_t hwReadConfig(int adr)
 {
-	uint8_t value;
-	hwReadConfigBlock(&value, reinterpret_cast<void*>(adr), 1);
-	return value;
+	return eep.read(adr);
 }
 
 void hwWriteConfig(int adr, uint8_t value)
 {
-	uint8_t curr = hwReadConfig(adr);
-	if (curr != value) {
-		hwWriteConfigBlock(&value, reinterpret_cast<void*>(adr), 1);
-	}
+	(void)eep.update(adr, value);
 }
 
 void hwInit()
@@ -105,7 +73,8 @@ void hwInit()
 #if defined(MY_GATEWAY_SERIAL)
 	while (!MY_SERIALDEVICE) {}
 #endif
-	Wire.begin();
+	// ext. EEPROM on sensebender GW
+	eep.begin(MY_EXT_EEPROM_TWI_CLOCK);
 }
 
 void hwWatchdogReset()

core/MyHwSAMD.h

@@ -20,22 +20,27 @@
 #define MyHwSAMD_h
 
 #include "MyHw.h"
-#include <Wire.h>
 
 #ifdef __cplusplus
 #include <Arduino.h>
-//#include <SPI.h>
 #endif
 
 #include <avr/dtostrf.h>
-#define I2C_EEP_ADDRESS 0x50
+
+// defines for sensebender gw variant.h
+#define MY_EXT_EEPROM_I2C_ADDRESS	(0x50)
+#define MY_EXT_EEPROM_SIZE			(kbits_512)
+#define MY_EXT_EEPROM_PAGE_SIZE		(32u)
+#define MY_EXT_EEPROM_TWI_CLOCK		(twiClock400kHz)
+
+extEEPROM eep(MY_EXT_EEPROM_SIZE, 1, MY_EXT_EEPROM_PAGE_SIZE,
+              MY_EXT_EEPROM_I2C_ADDRESS);	//device size, number of devices, page size
+
 
 #define min(a,b) ((a)<(b)?(a):(b))
 #define max(a,b) ((a)>(b)?(a):(b))
 #define snprintf_P(s, f, ...) snprintf((s), (f), __VA_ARGS__)
 
-uint8_t configBlock[1024];
-
 // Define these as macros to save valuable space
 #define hwDigitalWrite(__pin, __value) digitalWrite(__pin, __value)
 #define hwDigitalRead(__pin) digitalRead(__pin)