Communication i2c added readme

robotside/hexConverterv2.cpp

@@ -0,0 +1,134 @@
+#include <iostream>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/i2c-dev.h>
+#include <string>
+#include <stdio.h>
+#include <ros/ros.h>
+#include <stdlib.h>
+#include <std_msgs/MultiArrayLayout.h>
+#include <std_msgs/MultiArrayDimension.h>
+#include <std_msgs/UInt16MultiArray.h>
+
+
+
+using namespace std;
+
+int addr1 = 0x04;  //primary address //successive i2c devices
+int file_i2c; //primary address 
+int pwmVals[8];
+char *filename = (char*)"/dev/i2c-1";
+int i2c_slave_overflow = 32;
+
+void arrayCallback(const std_msgs::UInt16MultiArray::ConstPtr& array);
+
+bool writeStream(int file_i2c, string output) { 
+    if (output.length() <= i2c_slave_overflow) {
+        if (write(file_i2c, output.c_str(), output.length()) != output.length()) {
+            printf("\tFailed to write to the i2c bus.\n");
+        }
+    }
+    else {  
+        printf("\t\tinput too long |:| overflow bounds exceeded and message voided\n");
+    }
+    return true;
+}
+
+bool readStream(int file_i2c, char buf[]) {
+    int n=32; //this should be the number of expected characters
+    if (read(file_i2c, buf, n) != n) {
+        printf("\ti2c read transaction |:| failed\n");
+    }
+    else {
+        printf("\t%s\n", buf);
+    }
+}
+
+string intToHexDig(int value) {
+        string cHex;//this block can be written as a case statement, but im lazy
+        if (value == 15) {cHex = 'f';}
+        else if (value == 14) {cHex = 'e';}
+        else if (value == 13) {cHex = 'd';}
+        else if (value == 12) {cHex = 'c';}
+        else if (value == 11) {cHex = 'b';}
+        else if (value == 10) {cHex = 'a';}
+        else if (value == 9)  {cHex = '9';}
+        else if (value == 8)  {cHex = '8';}
+        else if (value == 7)  {cHex = '7';}
+        else if (value == 6)  {cHex = '6';}
+        else if (value == 5)  {cHex = '5';}
+        else if (value == 4)  {cHex = '4';}
+        else if (value == 3)  {cHex = '3';}
+        else if (value == 2)  {cHex = '2';}
+        else if (value == 1)  {cHex = '1';}
+        else if (value == 0)  {cHex = '0';}
+        return cHex;
+}
+
+string convertTo3BitHex(int decimal) {
+    string converted;
+    int firstChar = (int)(decimal/ (16 * 16));
+    int firstRemainder = (int)(decimal % (16 * 16));
+    int secondChar = (int)(firstRemainder / (16));
+    int secondRemainder = (int)(firstRemainder % (16));
+    int thirdChar = secondRemainder;
+    string cfirstChar, csecondChar, cthirdChar;
+    cfirstChar = intToHexDig(firstChar);
+    csecondChar = intToHexDig(secondChar);
+    cthirdChar = intToHexDig(thirdChar);
+
+    converted = converted + cfirstChar;
+    converted = converted + csecondChar;
+    converted = converted + cthirdChar;
+//    cout << converted << endl;
+//    cout << "done"<<endl;
+    return converted;
+}
+
+
+
+int main(int argc, char **argv) {
+	//Open i2c bus
+
+	if((file_i2c = open(filename, O_RDWR)) < 0) {
+		printf("\tFailed to open the i2c bus\n");
+	}
+	if(ioctl(file_i2c, I2C_SLAVE, addr1) < 0) {
+		printf("\tFailed to acquire bus access and/or talk to slave.\n");
+	}
+
+
+	ros::init(argc, argv, "pwmSubscriber");
+	ros::NodeHandle n;
+	ros::Subscriber subPWM = n.subscribe("array",1,arrayCallback);
+    while(ros::ok()){	
+        ros::spinOnce();
+    }
+	return 0;
+}
+
+
+
+void arrayCallback(const std_msgs::UInt16MultiArray::ConstPtr& array){
+	int i = 0;
+	for(std::vector<short unsigned int>::const_iterator it = array->data.begin(); it != array->data.end(); ++it){
+		pwmVals[i] = *it;
+		i++;
+	}
+    cout << pwmVals <<endl;
+	char hexVals[32];
+
+	string sinput1;
+	for (int i =0; i<8; i++){
+		int valueOf = pwmVals[i];
+		sinput1 = sinput1 + convertTo3BitHex(valueOf);
+		if(i<7){sinput1 = sinput1 + "~";}
+	}
+    cout << sinput1;
+    cout << endl;
+	writeStream (file_i2c, sinput1);
+    char buf2[32];
+	readStream(file_i2c, buf2);
+	return;
+}

robotside/i2c setup readme

@@ -0,0 +1,31 @@
+STEP I:
+  sudo apt-get install libi2c-dev i2c-tools
+STEP II:
+  sudo i2cdetect -y -r 1
+
+  should output...
+  0 1 2 3 4 5 6 7 8 9 a b c d e f
+00: — — — — — — — — — — — — —
+10: — — — — — — — — — — — — — — — —
+20: — — — — — — — — — — — — — — — —
+30: — — — — — — — — — — — — — — — —
+40: — — — — — — — — — — — — — — — —
+50: — — — — — — — — — — — — — — — —
+60: — — — — — — — — — — — — — — — —
+70: — — — — — — — — 
+
+STEP III:
+  connect the arduino to the nvidia with the provided arduino script and rerun 
+  sudo i2cdetect -y -r 1
+
+  should now output
+  0 1 2 3 4 5 6 7 8 9 a b c d e f
+00: — — — 04 — — — — — — — — —
+10: — — — — — — — — — — — — — — — —
+20: — — — — — — — — — — — — — — — —
+30: — — — — — — — — — — — — — — — —
+40: — — — — — — — — — — — — — — — —
+50: — — — — — — — — — — — — — — — —
+60: — — — — — — — — — — — — — — — —
+70: — — — — — — — — 
+

robotside/tester.cpp

@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ros/ros.h"
+
+#include "std_msgs/MultiArrayLayout.h"
+#include "std_msgs/MultiArrayDimension.h"
+
+#include "std_msgs/UInt16MultiArray.h"
+
+int main(int argc, char **argv)
+{
+
+
+	ros::init(argc, argv, "arrayPublisher");
+
+	ros::NodeHandle n;
+
+	ros::Publisher pub = n.advertise<std_msgs::UInt16MultiArray>("array", 1);
+
+	while (ros::ok())
+	{
+		std_msgs::UInt16MultiArray array;
+		//Clear array
+		array.data.clear();
+		//for loop, pushing data in the size of the array
+		for (int i = 0; i < 8; i++)
+		{
+			//assign array a random number between 0 and 255.
+			array.data.push_back(rand() % 255);
+		}
+		//Publish array
+		pub.publish(array);
+		//Let the world know
+		ROS_INFO("I published something!");
+		//Do this.
+		ros::spinOnce();
+		//Added a delay so not to spam
+		sleep(2);
+	}
+
+}