Firmware for MC33926 evaluation on KL25Z-based EVB. This works with a Graphical User Interface (GUI) available on NXP.com to control a brushed DC motor using FRDM-33926ESEVM or FRDM-33926PNBEVM. The code enables control of the PWM frequency, duty cycle, enable/disable controls, invert, slew rate control, real-time current monitoring, and includes status flag pin monitoring for undervoltage, short circuit and over-temperature events.

Dependencies:   USBDevice mbed

Fork of Brushed_DC_Motor_Control_MC33926 by Travis Alexander

Revision:
0:f2f48fcea638
diff -r 000000000000 -r f2f48fcea638 main_copy.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main_copy.cpp	Fri Jun 12 17:51:20 2015 +0000
@@ -0,0 +1,261 @@
+#include "mbed.h"
+#include "USBHID.h"
+
+// We declare a USBHID device.
+// HID In/Out Reports are 64 Bytes long
+// Vendor ID (VID):     0x15A2
+// Product ID (PID):    0x0138
+// Serial Number:       0x0001
+USBHID hid(64, 64, 0x15A2, 0x0138, 0x0001, true);
+
+//Setup Digital Outputs for the LEDs on the FRDM
+//PwmOut red_led(LED1);
+//DigitalOut green_led(LED2);
+//DigitalOut blue_led(LED3);
+
+//Setup PWM and Digital Outputs from FRDM-KL25Z to FRDM-17510
+PwmOut IN1(PTC8); // Pin IN1 input to MC34931 (FRDM PIN Name)
+PwmOut IN2 (PTA5); // Pin IN2 input to MC34931 (FRDM PIN Name)
+DigitalOut EN(PTE0); // Pin EN input to MC34931 (FRDM PIN Name)
+DigitalOut DIS(PTA2); //  Pin D1 input to MC34931 (FRDM PIN Name)
+DigitalIn STATUS(PTB3);
+AnalogIn CFB(PTB0);
+//DigitalOut READY(PTC7); // Pin READY input to Motor Control Board (FRDM PIN Name)
+
+//Variables
+int pwm_freq_lo;
+int pwm_freq_hi;
+int frequencyHz = 500;
+int runstop = 0;
+int direction = 1;
+int braking;
+int dutycycle = 75;
+int newDataFlag = 0;
+int status = 0;
+uint16_t CurrFB; 
+uint16_t CFBArray[101];
+uint32_t CFBTotal;
+uint16_t CFBAvg;
+uint16_t CFBtemp;
+
+//storage for send and receive data
+HID_REPORT send_report;
+HID_REPORT recv_report;
+
+bool initflag = true;
+
+// USB COMMANDS
+// These are sent from the PC
+#define WRITE_LED       0x20
+#define WRITE_GEN_EN  0x40
+#define WRITE_DUTY_CYCLE  0x50
+#define WRITE_PWM_FREQ  0x60
+#define WRITE_RUN_STOP  0x70
+#define WRITE_DIRECTION  0x71
+#define WRITE_BRAKING  0x90
+#define WRITE_RESET  0xA0
+#define WRITE_D1  0xB1
+#define WRITE_D2_B  0xC1
+
+#define scaleFactor 0.11868
+
+// LOGICAL CONSTANTS
+#define OFF             0x00
+#define ON              0x01
+
+
+int main() 
+{
+    send_report.length = 64;
+    recv_report.length = 64;
+    
+    
+    while(1) 
+    {
+               //try to read a msg
+        if(hid.readNB(&recv_report)) 
+        {
+            switch(recv_report.data[0])     //byte 0 of recv_report.data is command   
+            {
+//-----------------------------------------------------------------------------------------------------------------
+//          COMMAND PARSER
+//-----------------------------------------------------------------------------------------------------------------
+////////
+                case WRITE_LED:
+                    break;
+////////                    
+
+////////              
+                 case  WRITE_DUTY_CYCLE:
+                    dutycycle = recv_report.data[1];
+                    newDataFlag = 1;
+                    break;
+////////                
+                 case  WRITE_PWM_FREQ:                      //PWM frequency can be larger than 1 byte
+                    pwm_freq_lo = recv_report.data[1];      //so we have to re-assemble the number
+                    pwm_freq_hi = recv_report.data[2] * 100;
+                    frequencyHz = pwm_freq_lo + pwm_freq_hi;
+                    newDataFlag = 1;
+                    break;
+////////                
+                case  WRITE_RUN_STOP:
+                    newDataFlag = 1;                
+                    if(recv_report.data[1] != 0)
+                    {
+                         runstop = 1;
+                    }
+                    else
+                    {
+                         runstop = 0;
+                    } 
+                    break;                    
+ 
+////////                
+                case  WRITE_DIRECTION:
+                    newDataFlag = 1;
+ 
+                    if(recv_report.data[1] != 0)
+                    {
+                         direction = 1;
+                    }
+                    else
+                    {
+                         direction = 0;
+                    }                    
+                    break;
+////////
+                case  WRITE_BRAKING:
+                    newDataFlag = 1;                
+                    if(recv_report.data[1] == 1)
+                    {
+                            braking = 1;
+                    }
+                    else
+                    {
+                            braking = 0;
+                    }
+                    break;
+////////                   
+                case WRITE_D1:
+                    newDataFlag = 1;                                
+                    if(recv_report.data[1] == 1)
+                    {
+                        DIS = 1;
+                    }
+                    else
+                    {
+                        DIS = 0;
+                    }
+                    break;                    
+////////
+                case WRITE_D2_B:
+                    newDataFlag = 1;                
+                    if(recv_report.data[1] == 1)
+                    {
+                       EN  = 0;
+                    }
+                    else
+                    {
+                       EN = 1;
+                    }
+                    break;                    
+                
+////////                
+                default:
+                    break;
+            }// End Switch recv report data[0]
+
+//-----------------------------------------------------------------------------------------------------------------
+//      end command parser    
+//-----------------------------------------------------------------------------------------------------------------
+
+            status = STATUS;    
+            send_report.data[0] = status;      // Echo Command
+            send_report.data[1] = recv_report.data[1];      // Echo Subcommand 1
+            send_report.data[2] = recv_report.data[2];      // Echo Subcommand 2
+            send_report.data[3] = 0x00;
+            send_report.data[4] = 0x00;
+            send_report.data[5] = 0x00;
+            send_report.data[6] = (CFBAvg << 8) >> 8;
+            send_report.data[7] = CFBAvg >> 8;
+              
+            //Send the report
+            hid.send(&send_report);
+        }// End If(hid.readNB(&recv_report))
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//End of USB message handling        
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+        CurrFB = CFB.read_u16();
+        CFBArray[0] = CurrFB;
+        CFBTotal = 0;
+        int i = 0;
+        for(i=0; i<100; i++)
+        {
+        CFBTotal = CFBTotal + CFBArray[i];
+        }
+        CFBAvg =  CFBTotal / 100;
+        
+        for(i=100; i>=0; i--)
+        {
+           
+           CFBArray[i+1] = CFBArray[i];
+        }
+
+        if(newDataFlag != 0)                            //GUI setting changed
+        {
+            newDataFlag = 0;
+            if(runstop != 0)                            //Running 
+            {
+                if(direction == 0)                      //reverse
+                {
+                    if(braking == 1)                    //dynamic
+                    {
+                        IN1.period(1/(float)frequencyHz);    
+                        IN1 = (float)dutycycle/100.0;
+                        IN2 = 1;
+                    }
+                    else                                //coast
+                    {
+                        IN1 = 0;
+                        IN2.period(1/(float)frequencyHz);  
+                        IN2 = (float)dutycycle/100.0;                                    
+                    }
+                }
+                else                                    //forward
+                {
+                    if(braking == 1)                    //dynamic    
+                    {
+                        IN1 = 1;
+                        IN2.period(1/(float)frequencyHz); 
+                        IN2 = (float)dutycycle/100.0;   
+                    }
+                    else                                //coast
+                    {
+                        IN1.period(1/(float)frequencyHz);  
+                        IN1 = (float)dutycycle/100.0;                                    
+                        IN2 = 0;
+                    }
+                }                                    
+           }
+           else                                         //Stopped
+           {
+                if(braking == 1)    //braking
+                {
+                    IN1.period(1);
+                    IN2.period(1);
+                    IN1.write(1);
+                    IN2.write(1);    
+                }
+                else                //coasting
+                {
+                    IN1.period(1);
+                    IN2.period(1);                 
+                    IN1.write(0);
+                    IN2.write(0);  
+
+                }
+            }
+        }
+    }
+}