Add external EEPROM support for ESP8266

and support setting with MY_EXT_EEPROM definition

Author: virtual-maker

MySensors.h

@@ -55,6 +55,9 @@
 #include "hal/architecture/MyHwHAL.h"
 #include "hal/crypto/MyCryptoHAL.h"
 #if defined(ARDUINO_ARCH_ESP8266)
+#if defined(MY_EXT_EEPROM)
+#include "drivers/extEEPROM/extEEPROM.cpp"
+#endif
 #include "hal/architecture/ESP8266/MyHwESP8266.cpp"
 #include "hal/crypto/generic/MyCryptoGeneric.cpp"
 #elif defined(ARDUINO_ARCH_ESP32)

drivers/extEEPROM/extEEPROM.cpp

@@ -195,7 +195,11 @@ byte extEEPROM::read(unsigned long addr, byte *values, unsigned int nBytes)
 			return rxStatus;    //read error
 		}
 
+#if defined(ARDUINO_ARCH_ESP8266)
+		communication->requestFrom((int)ctrlByte, (int)nRead);
+#else
 		communication->requestFrom(ctrlByte, nRead);
+#endif	
 		for (byte i=0; i<nRead; i++) {
 			values[i] = communication->read();
 		}

hal/architecture/ESP8266/MyHwESP8266.cpp

@@ -28,10 +28,44 @@ bool hwInit(void)
 	while (!MY_SERIALDEVICE) {}
 #endif
 #endif
+#if defined(MY_EXT_EEPROM)
+	const uint8_t eepInit = eep.begin(MY_EXT_EEPROM_TWI_CLOCK, &Wire);
+	// check connection to external EEPROM and return result
+	return eepInit==0;
+#else
 	EEPROM.begin(EEPROM_size);
 	return true;
+#endif
 }
 
+#if defined(MY_EXT_EEPROM)
+void hwReadConfigBlock(void *buf, void *addr, size_t length)
+{
+	uint8_t *dst = static_cast<uint8_t *>(buf);
+	const int offs = reinterpret_cast<int>(addr);
+	(void)eep.read(offs, dst, length);
+}
+
+void hwWriteConfigBlock(void *buf, void *addr, size_t length)
+{
+	uint8_t *src = static_cast<uint8_t *>(buf);
+	const int offs = reinterpret_cast<int>(addr);
+	// use update() instead of write() to reduce e2p wear off
+	(void)eep.update(offs, src, length);
+}
+
+uint8_t hwReadConfig(const int addr)
+{
+	return eep.read(addr);
+}
+
+void hwWriteConfig(const int addr, uint8_t value)
+{
+	(void)eep.update(addr, value);
+}
+
+#else // !MY_EXT_EEPROM
+
 void hwReadConfigBlock(void *buf, void *addr, size_t length)
 {
 	uint8_t *dst = static_cast<uint8_t *>(buf);
@@ -63,6 +97,7 @@ void hwWriteConfig(const int addr, uint8_t value)
 {
 	hwWriteConfigBlock(&value, reinterpret_cast<void *>(addr), 1);
 }
+#endif //MY_EXT_EEPROM
 
 bool hwUniqueID(unique_id_t *uniqueID)
 {

hal/architecture/ESP8266/MyHwESP8266.h

@@ -22,7 +22,9 @@
 #include <SPI.h>
 #include <ESP8266WiFi.h>
 #include <WiFiUdp.h>
+#if !defined(MY_EXT_EEPROM)
 #include <EEPROM.h>
+#endif
 
 #ifdef __cplusplus
 #include <Arduino.h>
@@ -38,7 +40,19 @@
 #define MY_DEBUGDEVICE MY_SERIALDEVICE
 #endif
 
+#if defined(MY_EXT_EEPROM)
+// defines for external i2c EEPROM
+#define MY_EXT_EEPROM_I2C_ADDRESS	(0x50u)
+#define MY_EXT_EEPROM_SIZE			(kbits_1024)
+#define MY_EXT_EEPROM_PAGE_SIZE		(32u)
+
+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 MY_EXT_EEPROM_TWI_CLOCK		(eep.twiClock100kHz)	// can be set to 400kHz with precaution if other i2c devices on bus
+#else
 #define EEPROM_size (1024)
+#endif
 
 // Define these as macros to save valuable space
 #define hwDigitalWrite(__pin, __value) digitalWrite(__pin, __value)