main.cpp

00001 /*
00002 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
00003 % Generate WAVE Signal - 25/04/2018                %
00004 % Arkadi Rafalovich - % Arkadiraf@gmail.com         %
00005 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
00006 % Updates:
00007 % Disable interrupt during chirp out, fixes systic interrupt delays at 1ms interval for 0.5 us
00008 Pinout:
00009 DAC -- PA_4 -- A2
00010 
00011 I/O -- PA_5 -- D13 (Status LED, Condition)
00012 I/O -- PA_6 -- D12 (Toggle Pin, Loop Freq)
00013 Analog PA_0 -- A0  (Potentiometer)
00014 
00015 */
00016 #include "mbed.h"
00017 #include "signal.h"
00018 #define PULSE_RATE 10.0f // in HZ
00019 #define FREQ_POT_EN // Potentiometer to set PULSE Rate
00020 #define MIN_FREQ 0.1f //(HZ)
00021 #define SAMPLE_RATE_375_KHZ // basic sample rate is 1Mhz, this mode adds delay in between sample to meet the audio sample rate
00022 
00023 float pulseRate=PULSE_RATE;
00024 // Serial over USB as input device
00025 Serial pc(SERIAL_TX, SERIAL_RX);
00026 
00027 // mbed variables, Settings
00028 AnalogOut out(PA_4);
00029 AnalogIn potFreq(A0);
00030 // Potentiometer analog INPUT
00031 
00032 // digital pins
00033 DigitalOut led(LED1);
00034 DigitalOut outPulse(PA_6); // Toggle pin, Loop Freq
00035 
00036 // User Button as interrupt
00037 DigitalIn mybutton(USER_BUTTON);
00038 
00039 //DAC declarations
00040 DAC_HandleTypeDef hdac1;
00041 
00042 // Dac Register for direct method of setting DAC value`s
00043 __IO uint32_t Dac_Reg = 0;
00044 
00045 // Variables
00046 bool toggle_state=0;
00047 
00048 // nop operation
00049 inline void NOP()
00050 {
00051     __ASM volatile ("nop");    // one tick operation, Use to adjust frequency by slowing down the proccess
00052 }
00053 
00054 /* DAC1 init function */
00055 void DAC1_Init(void);
00056 
00057 // Main procedure
00058 int main()
00059 {
00060     DAC1_Init();
00061 
00062     HAL_DAC_Start(&hdac1, DAC_CHANNEL_1);
00063 
00064     // define Dac Register for direct method of setting DAC value`s
00065     Dac_Reg = (uint32_t) (hdac1.Instance);
00066     Dac_Reg += __HAL_DHR12R1_ALIGNEMENT(DAC_ALIGN_12B_R);
00067 
00068     // set outputs
00069     outPulse.write(0);
00070     led.write(0);
00071     // Output value using DAC
00072     // HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_1, DAC_ALIGN_12B_R, ADCValueOut);
00073     *(__IO uint32_t *) Dac_Reg = (uint16_t)(4095/2);
00074 
00075     // Infinite loop
00076     while(true) {
00077         if (mybutton.read()==0) { // if button pressed, generate pulse out
00078             led.write(1);
00079 
00080             /////////////////////////////////////////////////////////////////////////////////
00081             __disable_irq();    // Disable Interrupts
00082             // generate chirp out
00083             for (int ii=0; ii<NUM_SAMPLES; ii++) {
00084                 // toogle io for loop frequency
00085                 toggle_state=!toggle_state;
00086                 outPulse.write(toggle_state);
00087                 // generate delay for 1MHz Sample rate
00088                 for (int jj=0; jj<31; jj++) {
00089                     NOP();
00090                 }
00091                 // micro nops :)
00092                 NOP();
00093                 NOP();
00094                 NOP();
00095                 NOP();
00096                 NOP();
00097                 NOP();
00098                 NOP();
00099                 
00100                 #ifdef SAMPLE_RATE_375_KHZ
00101                 // generate delay
00102                 for (int jj=0; jj<61; jj++) {
00103                     NOP();
00104                 }
00105                 // micro nops :)
00106                 //NOP();
00107                 //NOP();
00108                 NOP();
00109                 NOP();
00110                 NOP();
00111                 #endif
00112                 // Output value using DAC
00113                 // HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_1, DAC_ALIGN_12B_R, ADCValueOut);
00114                 *(__IO uint32_t *) Dac_Reg = chirpData[ii];
00115             }
00116             // Output value using DAC
00117             // HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_1, DAC_ALIGN_12B_R, ADCValueOut);
00118             *(__IO uint32_t *) Dac_Reg = (uint16_t)(4095/2);
00119             __enable_irq();     // Enable Interrupts
00120             //////////////////////////////////////////////////////////////////////////////////
00121 
00122             // generate delay between pulses
00123             // delay post pulse // sets the pulse rate
00124             float waitTime = (1.0f/(2.0f*pulseRate) - (((float)NUM_SAMPLES)/1000000.0f));
00125             if (waitTime > 0) {
00126                 led.write(0);
00127                 wait(waitTime);
00128                 led.write(1);
00129                 wait(1.0f/(2.0f*pulseRate));
00130             } else {
00131                 wait(0.5);
00132                 printf("!!! Error Wait time is negative %f !!!\r\n", waitTime);
00133                 wait(0.5);
00134             }
00135         } // end button press
00136         led.write(0);
00137 
00138         // update freq based on potentiometer
00139 #ifdef FREQ_POT_EN 
00140         pulseRate = potFreq * PULSE_RATE;
00141         if (pulseRate < MIN_FREQ) pulseRate = MIN_FREQ;
00142         //printf("Pulse Rate %f\r\n", pulseRate);     
00143 #endif
00144     }// end while(True)
00145 }
00146 
00147 
00148 // init dac
00149 
00150 /* DAC1 init function */
00151 void DAC1_Init(void)
00152 {
00153     DAC_ChannelConfTypeDef sConfig;
00154 
00155     // DAC Initialization
00156     hdac1.Instance = DAC;
00157     if(HAL_DAC_Init(&hdac1) != HAL_OK) {
00158         printf("!!! Error in DAC initialization !!!\r\n");
00159     }
00160 
00161     // DAC channel OUT1 config
00162     sConfig.DAC_Trigger = DAC_TRIGGER_NONE;
00163     sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
00164     if (HAL_DAC_ConfigChannel(&hdac1, &sConfig, DAC_CHANNEL_1) != HAL_OK) {
00165         printf("!!! Error in DAC channel initialization !!!\r\n");
00166     }
00167 }