Functions to write and read string objects

examples/Example1_BasicReadWrite/Example1_BasicReadWrite.ino

@@ -1,72 +1,81 @@
-/*
-  Read and write settings and calibration data to an external I2C EEPROM
-  By: Nathan Seidle
-  SparkFun Electronics
-  Date: December 11th, 2019
-  License: This code is public domain but you buy me a beer if you use this 
-  and we meet someday (Beerware license).
-  Feel like supporting our work? Buy a board from SparkFun!
-  https://www.sparkfun.com/products/14764
-
-  This example demonstrates how to read and write various variables to memory.
-
-  The I2C EEPROM should have all its ADR pins set to GND (0). This is default
-  on the Qwiic board.
-
-  Hardware Connections:
-  Plug the SparkFun Qwiic EEPROM to an Uno, Artemis, or other Qwiic equipped board
-  Load this sketch
-  Open output window at 115200bps
-*/
-
-#include <Wire.h>
-
-#include "SparkFun_External_EEPROM.h" // Click here to get the library: http://librarymanager/All#SparkFun_External_EEPROM
-ExternalEEPROM myMem;
-
-void setup()
-{
-  Serial.begin(115200);
-  Serial.println("Qwiic EEPROM example");
-
-  Wire.begin();
-
-  if (myMem.begin() == false)
-  {
-    Serial.println("No memory detected. Freezing.");
-    while (1)
-      ;
-  }
-  Serial.println("Memory detected!");
-
-  Serial.print("Mem size in bytes: ");
-  Serial.println(myMem.length());
-
-  //Yes you can read and write bytes, but you shouldn't!
-  byte myValue1 = 200;
-  myMem.write(0, myValue1); //(location, data)
-
-  byte myRead1 = myMem.read(0);
-  Serial.print("I read: ");
-  Serial.println(myRead1);
-
-  //You should use gets and puts. This will automatically and correctly arrange
-  //the bytes for larger variable types.
-  int myValue2 = -366;
-  myMem.put(10, myValue2); //(location, data)
-  int myRead2;
-  myMem.get(10, myRead2); //location to read, thing to put data into
-  Serial.print("I read: ");
-  Serial.println(myRead2);
-
-  float myValue3 = -7.35;
-  myMem.put(20, myValue3); //(location, data)
-  float myRead3;
-  myMem.get(20, myRead3); //location to read, thing to put data into
-  Serial.print("I read: ");
-  Serial.println(myRead3);
-}
-
-void loop()
-{
-}
+/*
+  Read and write settings and calibration data to an external I2C EEPROM
+  By: Nathan Seidle
+  SparkFun Electronics
+  Date: December 11th, 2019
+  License: This code is public domain but you buy me a beer if you use this 
+  and we meet someday (Beerware license).
+  Feel like supporting our work? Buy a board from SparkFun!
+  https://www.sparkfun.com/products/14764
+
+  This example demonstrates how to read and write various variables to memory.
+
+  The I2C EEPROM should have all its ADR pins set to GND (0). This is default
+  on the Qwiic board.
+
+  Hardware Connections:
+  Plug the SparkFun Qwiic EEPROM to an Uno, Artemis, or other Qwiic equipped board
+  Load this sketch
+  Open output window at 115200bps
+*/
+
+#include <Wire.h>
+
+#include "SparkFun_External_EEPROM.h" // Click here to get the library: http://librarymanager/All#SparkFun_External_EEPROM
+ExternalEEPROM myMem;
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println("Qwiic EEPROM example");
+
+  Wire.begin();
+
+  if (myMem.begin() == false)
+  {
+    Serial.println("No memory detected. Freezing.");
+    while (1)
+      ;
+  }
+  Serial.println("Memory detected!");
+
+  Serial.print("Mem size in bytes: ");
+  Serial.println(myMem.length());
+
+  //Yes you can read and write bytes, but you shouldn't!
+  byte myValue1 = 200;
+  myMem.write(0, myValue1); //(location, data)
+
+  byte myRead1 = myMem.read(0);
+  Serial.print("I read: ");
+  Serial.println(myRead1);
+
+  //You should use gets and puts. This will automatically and correctly arrange
+  //the bytes for larger variable types.
+  int myValue2 = -366;
+  myMem.put(10, myValue2); //(location, data)
+  int myRead2;
+  myMem.get(10, myRead2); //location to read, thing to put data into
+  Serial.print("I read: ");
+  Serial.println(myRead2);
+
+  float myValue3 = -7.35;
+  myMem.put(20, myValue3); //(location, data)
+  float myRead3;
+  myMem.get(20, myRead3); //location to read, thing to put data into
+  Serial.print("I read: ");
+  Serial.println(myRead3);
+
+  String myString = "Hi, I am just a simple test string";
+  unsigned long nextEEPROMLocation = myMem.putString(30, myString);
+  String myRead4 = "";
+  myMem.getString(30, myRead4);
+  Serial.print("I read: ");
+  Serial.println(myRead4);
+  Serial.print("Next available EEPROM location: ");
+  Serial.println(nextEEPROMLocation);  
+}
+
+void loop()
+{
+}

keywords.txt

@@ -31,6 +31,8 @@ get	KEYWORD2
 put	KEYWORD2
 setI2CBufferSize	KEYWORD2
 getI2CBufferSize	KEYWORD2
+putString	KEYWORD2
+getString	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)

src/SparkFun_External_EEPROM.cpp

@@ -119,6 +119,26 @@ constexpr uint16_t ExternalEEPROM::getI2CBufferSize()
 {
   return I2C_BUFFER_LENGTH_TX;
 }
+uint32_t ExternalEEPROM::putString(uint32_t eepromLocation, String &strToWrite)
+{
+  uint16_t strLen = strToWrite.length() + 1; 
+  write(eepromLocation, (uint8_t*)strToWrite.c_str(), strLen);
+  return eepromLocation + strLen;
+}
+void ExternalEEPROM::getString(uint32_t eepromLocation, String &strToRead)
+{
+  if(strToRead.length()){
+    strToRead.remove(0,strToRead.length());
+  }
+  uint8_t tmp = 65; // dummy
+  while(tmp != 0){
+    tmp = read(eepromLocation);
+    if(tmp != 0){
+      strToRead += static_cast<char>(tmp);
+    }
+      eepromLocation++;
+    }   
+}
 //Read a byte from a given location
 uint8_t ExternalEEPROM::read(uint32_t eepromLocation)
 {

src/SparkFun_External_EEPROM.h

@@ -147,13 +147,16 @@ class ExternalEEPROM
     write(idx, ptr, sizeof(T)); //Address, data, sizeOfData
     return t;
   }
+
+  uint32_t putString(uint32_t eepromLocation, String &strToWrite);
+  void getString(uint32_t eepromLocation, String &strToRead);
 
 private:
   // Default settings are for onsemi CAT24C51 512Kbit I2C EEPROM used on SparkFun Qwiic EEPROM Breakout
   struct_memorySettings settings = {
       .i2cPort = &Wire,
-      .deviceAddress = 0b1010000, 			// 0x50; format is 0b1010 + (A2 A1 A0) or 0b1010 + (B0 A1 A0) for larger (>512kbit) EEPROMs
-      .memorySize_bytes = (uint32_t)512 * 1024 / 8,	// equals 64 KB
+      .deviceAddress = 0b1010000,           // 0x50; format is 0b1010 + (A2 A1 A0) or 0b1010 + (B0 A1 A0) for larger (>512kbit) EEPROMs
+      .memorySize_bytes = (uint32_t)512 * 1024 / 8, // equals 64 KB
       .pageSize_bytes = 64,
       .pageWriteTime_ms = 5,
       .pollForWriteComplete = true