Revision 0:375ecd0ed73d, committed 2011-05-12

Comitter:

ShockSoc

Date:

Thu May 12 09:24:27 2011 +0000

Commit message:

Changed in this revision

diff -r 000000000000 -r 375ecd0ed73d I2CR.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2CR.cpp	Thu May 12 09:24:27 2011 +0000
@@ -0,0 +1,184 @@
+#include "I2CR.h"
+
+//Constructor
+I2CR::I2CR() {
+
+    //set pins to i2c1
+    LPC_PINCON->PINSEL0 = LPC_PINCON->PINSEL0 | 0xF;
+    //set to no pull up/down resistors
+    LPC_PINCON->PINMODE0 = LPC_PINCON->PINMODE0 | 0xA;
+    //set to open drain mode
+    LPC_PINCON->PINMODE_OD0 = LPC_PINCON->PINMODE_OD0 | 0x3;
+
+    //turn on power
+    LPC_SC->PCONP = LPC_SC->PCONP | 0x00080000;
+
+    //set clock to 100kHz
+    LPC_I2C1->I2SCLL = 120;
+    LPC_I2C1->I2SCLH = 120;
+
+    //enable i2c1 i2en
+    LPC_I2C1->I2CONSET = 0x40;
+    //clear sta si and aa
+    LPC_I2C1->I2CONCLR = 0x2C;
+
+
+}
+
+//Write function
+int I2CR::write(int address, const char* data, int length) {
+    //MASTER TRANSMITTER
+
+    //send start condition
+    LPC_I2C1->I2CONSET = 0x20;
+
+    //block until interrupt
+    while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+    //i2stat should be 0x08. could check
+    if (LPC_I2C1->I2STAT != 0x08) {
+        printf("START %x\r\n",LPC_I2C1->I2STAT);
+        //stop if failed
+        LPC_I2C1->I2CONSET = 0x10;
+        return -1;
+    }
+
+    //clear start condition
+    LPC_I2C1->I2CONCLR = 0x20;
+
+    //load i2dat
+    LPC_I2C1->I2DAT = address;
+
+    //reset si
+    LPC_I2C1->I2CONCLR = 0x08;
+
+    //block until interrupt
+    while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+    //i2stat should be ack received
+    if (LPC_I2C1->I2STAT != 0x18) {
+        printf("ADD %x\r\n",LPC_I2C1->I2STAT);
+        //stop
+        LPC_I2C1->I2CONSET = 0x10;
+        return -1;
+    }
+
+    for (int i=0; i<length; i++) {
+    
+        //load i2dat
+        LPC_I2C1->I2DAT = data[i];
+
+        //reset si
+        LPC_I2C1->I2CONCLR = 0x08;
+
+        //block until interrupt
+        while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+        //i2stat should be ack received
+        if (LPC_I2C1->I2STAT != 0x28) {
+            printf("DATA%d %x\r\n",i,LPC_I2C1->I2STAT);
+            //stop
+            LPC_I2C1->I2CONSET = 0x10;
+            return -1;
+        }
+    }
+
+    //stop
+    LPC_I2C1->I2CONSET = 0x10;
+
+    //reset si
+    LPC_I2C1->I2CONCLR = 0x08;
+
+    return 0;
+}
+
+
+int I2CR::read(int address, char* data, int length) {
+
+    //MASTER RECEIVER
+
+    //send start condition
+    LPC_I2C1->I2CONSET = 0x20;
+
+    //block until interrupt
+    while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+    //i2stat should be 0x08. could check
+    if (LPC_I2C1->I2STAT != 0x08) {
+        printf("RSTART %x\r\n",LPC_I2C1->I2STAT);
+        //stop if failed
+        LPC_I2C1->I2CONSET = 0x10;
+        return -1;
+    }
+
+    //clear start condition
+    LPC_I2C1->I2CONCLR = 0x20;
+
+    //load i2dat with read bit set
+    LPC_I2C1->I2DAT = address | 0x1;
+
+    //reset si
+    LPC_I2C1->I2CONCLR = 0x08;
+
+    //block until interrupt
+    while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+    //i2stat should be 0x40 - ack received
+    if (LPC_I2C1->I2STAT != 0x40) {
+        printf("RADD %x\r\n",LPC_I2C1->I2STAT);
+        //stop
+        LPC_I2C1->I2CONSET = 0x10;
+        return -1;
+    }
+
+    for (int i=0; i<length-1; i++) {
+
+        //ack next byte
+        LPC_I2C1->I2CONSET = 0x4;
+
+        //reset si
+        LPC_I2C1->I2CONCLR = 0x08;
+
+        //block until interrupt
+        while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+        //i2stat should be 0x50, byte received, ack sent
+        if (LPC_I2C1->I2STAT != 0x50) {
+            printf("rDATA%d %x\r\n",i,LPC_I2C1->I2STAT);
+            //stop
+            LPC_I2C1->I2CONSET = 0x10;
+            return -1;
+        }
+
+        data[i] = LPC_I2C1->I2DAT;
+    }
+
+    //last byte
+    //nack next byte
+    LPC_I2C1->I2CONCLR = 0x4;
+
+    //reset si
+    LPC_I2C1->I2CONCLR = 0x08;
+
+    //block until interrupt
+    while ((LPC_I2C1->I2CONSET & 0x8) != 0x8) {}
+
+    //i2stat should be 0x58, byte received, nack sent
+    if (LPC_I2C1->I2STAT != 0x58) {
+        printf("lastd %x\r\n",LPC_I2C1->I2STAT);
+        //stop
+        LPC_I2C1->I2CONSET = 0x10;
+        return -1;
+    }
+
+    data[length-1] = LPC_I2C1->I2DAT;
+
+    //stop
+    LPC_I2C1->I2CONSET = 0x10;
+
+    //reset si
+    LPC_I2C1->I2CONCLR = 0x08;
+
+    return 0;
+
+}

diff -r 000000000000 -r 375ecd0ed73d I2CR.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2CR.h	Thu May 12 09:24:27 2011 +0000
@@ -0,0 +1,34 @@
+/**
+*   Author: Rob Hyams
+*   Date:   12.05.2011
+*   This is a beta library for use with I2C1. The standard mbed I2C
+*   is not currently functioning when using the v29 beta library.
+*   Therefore, this has been developed as a drop in replacement.
+*   Code is not particularly robust, but will handle incorrect
+*   communication by checking states.
+*
+*   Has been developed and tested with ADXL345 accelerometer
+*/
+
+
+
+#ifndef I2CR_H
+#define I2CR_H
+
+#include "mbed.h"
+
+class I2CR {
+
+public:
+    //Constructor
+    I2CR();
+    
+    //Write function
+    int write(int address, const char* data, int length);
+    
+    //Read function
+    int read(int address, char* data, int length);
+
+};
+
+#endif
\ No newline at end of file