Posts Tagged PWM
Xduino v0.12 to be released
Posted by Ram in ARM, Cortex-M3, Xduino release on July 24, 2009
Here is an example for dimming the LED connected to PA4 while attaching interrupt to PB8 and PB9. It has been tested with Xduino v0.3 (more projects and examples will be added in the near future)
/* Xduino v0.3 */ #include "main.h" using namespace compatArduino; void InterruptPB9(void) { Serial1.printf("(interrupt 9!!! %d) ", digitalRead(PB9)); } void InterruptPB8(void) { Serial1.printf("(interrupt 8!!! %d) ", digitalRead(PB8)); } int LedPin = PB7; // as labelled on ARM Cortex-M3 board int main(void) { float version=0.3; double fnumber=1234.5678; char myinput; doInit(); //Initialize Xduino components, this line is required Serial1.begin(115200); //USART1 Serial1.printf("Starting Xduino (v%f) example program...",version); Serial1.printf("hello!! %d %d %d ",1,2,3); Serial1.printf("The floating point number is %d ",fnumber); pinMode(LedPin,OUTPUT); pinMode(PB1,OUTPUT); pinMode(PB8,INPUT); pinMode(PB9,INPUT); digitalWrite(PB1,HIGH); attachInterrupt(PB9,InterruptPB9,CHANGE); attachInterrupt(PB8,InterruptPB8,RISING); while(1) { if(Serial1.available()) { myinput=Serial1.read(); Serial1.printf("This system has been up for %lu milliseconds. ",millis()); if(myinput=='a') { digitalWrite(PB1,HIGH); } // press a to turn PB1 to HIGH state if(myinput=='b') { digitalWrite(PB1,LOW); } // press b to turn PB1 to HIGH state if(myinput=='n') { noInterrupts(); } // press n to disable all existing interrupts if(myinput=='i') { interrupts(); } // press i to enable all existing interrupts Serial1.printf("Input is %c ... ",myinput); } //using analogWrite on channel 1 which is PA4 to dim the LED connected to it for(int i=0;i<=0x0FFF;i+=0xFF) // smoothly turn PA4 (DAC port 1) on { analogWrite(1,i); delay(50); } for(int j=0x0FFF;j>=0;j-=0xFF) // smoothly turn PA4 (DAC port 1) off { analogWrite(1,j); delay(50); } analogWrite(1,0xFFF); // Turn on PA4 fully at once delay(100); digitalWrite(LedPin,LOW); // Turn off PA4 fully at once delay(100); } //## END while(1) } //## END main()
Xduino v0.12 should come out within the next few days and it will have Serial buffer, Round-robin general purpose library, ADC (Analog input) and might also have DAC (Analog output) functionalities. Note DAC function does not exist in Arduino (yet). PWM function should be coming out soon as well but might not always be needed as there are 2 DAC channels on the ARM Cortex-M3 STM32F10ret6 board which is being used for testing. Arduino compatibility syntax will be provided on the new functions as well.