library for implementing ir transmission
XMIT_IR.cpp
- Committer:
- cmulady
- Date:
- 2012-10-06
- Revision:
- 4:55946953c6e3
- Parent:
- 3:823708586b3e
- Child:
- 5:ad52a062d494
File content as of revision 4:55946953c6e3:
#include "mbed.h" #include "XMIT_IR.h" IRTransmitter::IRTransmitter(PinName TX, PinName PWM, PinName RX, int data_buff_len, void (*fptr)(void)) { ir_serial = new Serial(TX,RX); ir_pwm = new PwmOut(PWM); packet_buffer_out = new char[data_buff_len](); packet_buffer_in = new char[data_buff_len+3](); //Initialize modules (*ir_pwm).period(1.0/38000.0); //38kHz Modulation Freq (*ir_pwm) = 0.5; //pulse width = 50% (*ir_serial).baud(2400); (*ir_serial).attach(fptr,Serial::RxIrq); //Initialize Variables for(int i=0; i<data_buff_len+3; i++) packet_buffer_in[i] = 0; } IRTransmitter::~IRTransmitter() { delete ir_serial; delete ir_pwm; delete packet_buffer_out; delete packet_buffer_in; } void IRTransmitter::set_debug_port(Serial* port) { debug_port = port; } void IRTransmitter::MakePacket(char* data,int len) { char check =0x0; (*ir_serial).putc(ASCII_STX); for(int i=0; i<len; i++) { check^=data[i]; (*ir_serial).putc(data[i]); } (*ir_serial).putc(check); (*ir_serial).putc(ASCII_ETX); } /*char IRTransmitter::ReadPacket(char* data) { osEvent evt = ir_data_mailbox.get(); if(evt.status == osEventMail) { char* mail = (char*)evt.value.p; (*data) = (*mail); ir_data_mailbox.free(mail); return 0; } return 1; }*/ char IRTransmitter::ReadPacket(char* data, int len) { //Run this every few milliseconds to run through mailbox and check packet data. //The data array will update with new values once a packet has been validated. //Returns true if new data, false otherwise //Inputs: // -data: a character array to store data variables // -len: length of character array char return_state=0; osEvent evt = ir_data_mailbox.get(); while(evt.status == osEventMail) { char* mail = (char*)evt.value.p; (*data) = (*mail); //check for valid packet - update data if so update_packet_buffer(*data,len); /*(*debug_port).printf("\n"); for(int i=0; i<len+3; i++) { (*debug_port).printf("0x%02X.",packet_buffer_in[i]); } (*debug_port).printf(" PKT_VALID=0x%02X.",packet_is_valid(len));*/ if(packet_is_valid(len)==0) { return_state = 1; for(int i=0; i<len; i++) { data[i] = packet_buffer_in[i+1]; } } ir_data_mailbox.free(mail); if(return_state) { return return_state; } evt = ir_data_mailbox.get(); } return return_state; } char IRTransmitter::packet_is_valid(int data_len) { char check = 0; //check for valid packet if(packet_buffer_in[0]!=ASCII_STX) return 0x1; //bad start byte if(packet_buffer_in[data_len+2]!=ASCII_ETX) return 0x2; //bad end byte for(int i=1; i<data_len+1; i++) { check^=packet_buffer_in[i]; } if(check!=packet_buffer_in[data_len+1]) { return 0x3; //bad checksum } return 0; } void IRTransmitter::update_packet_buffer(char new_data, int data_len) { //Shift All data 1 cell over for(int i=0; i<data_len+2; i++) { packet_buffer_in[i] = packet_buffer_in[i+1]; } packet_buffer_in[data_len+2] = new_data; } void IRTransmitter::isr(char data) { char* mail = ir_data_mailbox.alloc(); mail[0] = (char)data; ir_data_mailbox.put(mail); }