Revision 0:a51016633386, committed 2014-12-16

Comitter:

martinsimpson

Date:

Tue Dec 16 09:13:45 2014 +0000

Commit message:

First Published Program 24AA02 2K EEPROM using i2c Address

Changed in this revision

diff -r 000000000000 -r a51016633386 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Dec 16 09:13:45 2014 +0000
@@ -0,0 +1,117 @@
+#include "mbed.h"
+ 
+#define MCP24AA02_ADDR     (0xA0) // 24AA02 2K EEPROM using i2c Address
+                                  // for the 22AA025 variant this can be 0xA0,0xA2,0xA4,0xA6,0xA8,0xAA,0xAC,0xAE
+                                  // since LSB is used to to control a WRITE(0) or a READ(1) Operation
+#define WRITE              (0x00) // 24AA02 2K EEPROM using i2c Write bit
+#define READ               (0x01) // 24AA02 2K EEPROM using i2c Read bit
+#define MCP24AA02_MID      (0xFA) // Manufacturer ID Address (Read Only 0x29==Microchip)
+#define MCP24AA02_DID      (0xFB) // Device ID Adress (Read Only 0x41==4 is i2c family and 1 is 2K device)
+                                  // Information from Microchip Datasheet DS20005202A Part #24AA02UID/24AA025UID
+/* This is a very simple program to demonstrate the ease of use of the i2c bus utilising an EEPROM.
+   Do not forget that Pull Up resistors are required on the SDA and SCL lines
+   (Typically 2K ohms for 400KHz bus speeds)
+   These are required since devices connected with the i2c will have 'open drain' (or open collector)
+   circuitry to allow wire 'ORing' of their respective connections
+   Used with a stm32-Nucleo-F401RE
+*/
+
+I2C i2c(I2C_SDA, I2C_SCL); //I2C Class Pin Assignments see I2C.h
+ 
+Serial pc(SERIAL_TX, SERIAL_RX); //Serial Class Pin Assignments see Serial.h
+
+void readID(int addy)
+{
+    char ucdata_write[1];
+    char ucdata_read[1];
+    ucdata_write[0] = addy; //MCP24AA02_DID, Address here for Device ID
+    
+    while (i2c.write((MCP24AA02_ADDR|WRITE), ucdata_write, 1, 0)){} //Wait for ACK if EEPROM is in 'write' cycle
+    
+    {
+        i2c.read((MCP24AA02_ADDR|READ),ucdata_read,1,0);
+        if (ucdata_read[0]==0x29)
+        {
+            pc.printf("Code=%#x (Microchip Technology ltd.(c))\n\r",ucdata_read[0]);return;
+        }
+        if (ucdata_read[0]==0x41)
+        {
+            pc.printf("Code=%#x (2K EEPROM Using i2c)\n\r",ucdata_read[0]);
+        }
+        else
+        {
+            pc.printf("0x%x 0x%X %c\n\r",addy,ucdata_read[0],(ucdata_read[0]));
+        }    
+     }
+}
+
+void readEE(int addy)
+{
+    char ucdata_write[1];
+    char ucdata_read[1];
+    ucdata_write[0] = addy; //Address here to read
+    while (i2c.write((MCP24AA02_ADDR|WRITE), ucdata_write, 1, 0)){} //Wait for ACK if EEPROM is in 'write' cycle
+    i2c.read((MCP24AA02_ADDR|READ),ucdata_read,1,0); //Note 'OR' Address with Read bit
+    pc.printf("%#X %c",ucdata_read[0],ucdata_read[0]);
+ }
+
+void writeEE(int addy,int data)
+{
+    char ucdata_write[2];
+    ucdata_write[0] = addy;
+    ucdata_write[1] = data;
+    while (i2c.write((MCP24AA02_ADDR|WRITE), ucdata_write, 1, 0)){} //Wait for ACK if EEPROM is in 'write' cycle
+    i2c.write((MCP24AA02_ADDR|WRITE),ucdata_write,2,0); //Note 'OR' Adress with Write bit
+    pc.printf("%04d %c\t",addy,data);
+}
+
+void eraseEE(void)
+{
+    for (int i=0;i<0xFA;i++) //0xFA to 0xFF are read only with Manufacture/Hardware ID and a Unique Serial Number
+    {
+        writeEE(i,0xFF);
+    }
+}
+
+int main()
+{
+    unsigned int uibaudrate=115200;
+    pc.baud(uibaudrate);
+    
+    unsigned int uifrequency=400000; //400KHz for i2c Max
+    i2c.frequency (uifrequency);
+
+    char ucdata_write[1];    
+    if (!i2c.write((MCP24AA02_ADDR|WRITE), ucdata_write, 1, 0))// Check for ACK from EPPROM
+    {
+        pc.printf("\n\rHello World ");
+        pc.printf("at %u BAUD and %uKHz i2c Frequency\n\r",uibaudrate,uifrequency/1000);
+        pc.printf("Using mbed.org Martin\n\r");
+        readID(MCP24AA02_MID);
+        readID(MCP24AA02_DID);
+        //  Uncomment the following 6 lines of code to write Data into the EEPROM
+        /*
+        writeEE(0x00,0x4D); // ASCII M
+        writeEE(0x01,0x61); // ASCII a
+        writeEE(0x02,0x72); // ASCII r
+        writeEE(0x03,0x74); // ASCII t
+        writeEE(0x04,0x69); // ASCII i
+        writeEE(0x05,0x6E); // ASCII n
+        pc.printf("\n\r");
+        */
+
+        //Uncomment the following line to Erase the EEPROM
+        // eraseEE();
+    
+        for (int i=0;i<=0x5;i++) //Just going to read the first 6 (zero to five) locations in the EEPROM
+        {
+            readEE(i);pc.printf("\t");          //A Bit of formating going to tab into 8 columns
+            if (!((i+1)%8)){pc.printf("\n\r");} //of data
+        }
+    }
+    else
+    {
+        pc.printf("\n\rCannot get an ACK from the Device check connections!\n\r");
+    }
+}
+  
\ No newline at end of file

diff -r 000000000000 -r a51016633386 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Dec 16 09:13:45 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/4fc01daae5a5
\ No newline at end of file