Ross Squires / SoftSerial

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Fork of SoftSerial by Erik -

SoftSerial_rx.cpp@1:f8b4b764ace7, 2014-04-26 (annotated)

Committer:
Sissors
Date:
Sat Apr 26 15:13:01 2014 +0000
Revision:
1:f8b4b764ace7
Parent:
0:8edaa7abe724
Child:
3:7238e9bb74d2
RX basic functional

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 0:8edaa7abe724 1 #include "SoftSerial.h"
Sissors 0:8edaa7abe724 2
Sissors 0:8edaa7abe724 3 int SoftSerial::_getc( void ) {
Sissors 1:f8b4b764ace7 4 while(!readable());
Sissors 1:f8b4b764ace7 5 out_valid = false;
Sissors 1:f8b4b764ace7 6 return out_buffer;
Sissors 1:f8b4b764ace7 7 }
Sissors 0:8edaa7abe724 8
Sissors 1:f8b4b764ace7 9 int SoftSerial::readable(void) {
Sissors 1:f8b4b764ace7 10 return out_valid;
Sissors 1:f8b4b764ace7 11 }
Sissors 1:f8b4b764ace7 12
Sissors 1:f8b4b764ace7 13 //Start receiving byte
Sissors 0:8edaa7abe724 14 void SoftSerial::rx_gpio_irq_handler(void) {
Sissors 1:f8b4b764ace7 15 rx->fall(NULL);
Sissors 1:f8b4b764ace7 16 rx_bit = 0;
Sissors 1:f8b4b764ace7 17 rx_error = false;
Sissors 1:f8b4b764ace7 18 rxout.attach_us(this, &SoftSerial::rx_handler, bit_period + (bit_period >> 1)); //Start reading first data byte
Sissors 0:8edaa7abe724 19 };
Sissors 1:f8b4b764ace7 20
Sissors 1:f8b4b764ace7 21 void SoftSerial::rx_handler(void) {
Sissors 1:f8b4b764ace7 22 rx_bit++;
Sissors 1:f8b4b764ace7 23 rxout.attach_us(this, &SoftSerial::rx_handler, bit_period);
Sissors 1:f8b4b764ace7 24
Sissors 1:f8b4b764ace7 25 //Receive data
Sissors 1:f8b4b764ace7 26 int val = rx->read();
Sissors 1:f8b4b764ace7 27 if (rx_bit <= _bits) {
Sissors 1:f8b4b764ace7 28 read_buffer |= val << (rx_bit - 1);
Sissors 1:f8b4b764ace7 29 return;
Sissors 1:f8b4b764ace7 30 }
Sissors 1:f8b4b764ace7 31
Sissors 1:f8b4b764ace7 32 //Receive parity
Sissors 1:f8b4b764ace7 33 bool parity_count;
Sissors 1:f8b4b764ace7 34 if (rx_bit == _bits + 1) {
Sissors 1:f8b4b764ace7 35 switch (_parity) {
Sissors 1:f8b4b764ace7 36 case Forced1:
Sissors 1:f8b4b764ace7 37 if (val == 0)
Sissors 1:f8b4b764ace7 38 rx_error = true;
Sissors 1:f8b4b764ace7 39 return;
Sissors 1:f8b4b764ace7 40 case Forced0:
Sissors 1:f8b4b764ace7 41 if (val == 1)
Sissors 1:f8b4b764ace7 42 rx_error = true;
Sissors 1:f8b4b764ace7 43 return;
Sissors 1:f8b4b764ace7 44 case Even:
Sissors 1:f8b4b764ace7 45 case Odd:
Sissors 1:f8b4b764ace7 46 parity_count = val;
Sissors 1:f8b4b764ace7 47 for (int i = 0; i<_bits; i++) {
Sissors 1:f8b4b764ace7 48 if (((read_buffer >> i) & 0x01) == 1)
Sissors 1:f8b4b764ace7 49 parity_count = !parity_count;
Sissors 1:f8b4b764ace7 50 }
Sissors 1:f8b4b764ace7 51 if ((parity_count) && (_parity == Even))
Sissors 1:f8b4b764ace7 52 rx_error = true;
Sissors 1:f8b4b764ace7 53 if ((!parity_count) && (_parity == Odd))
Sissors 1:f8b4b764ace7 54 rx_error = true;
Sissors 1:f8b4b764ace7 55 return;
Sissors 1:f8b4b764ace7 56 }
Sissors 1:f8b4b764ace7 57 }
Sissors 1:f8b4b764ace7 58
Sissors 1:f8b4b764ace7 59 //Receive stop
Sissors 1:f8b4b764ace7 60 if (rx_bit < _bits + (bool)_parity + _stop_bits) {
Sissors 1:f8b4b764ace7 61 if (!val)
Sissors 1:f8b4b764ace7 62 rx_error = true;
Sissors 1:f8b4b764ace7 63 return;
Sissors 1:f8b4b764ace7 64 }
Sissors 1:f8b4b764ace7 65
Sissors 1:f8b4b764ace7 66 //The last stop bit
Sissors 1:f8b4b764ace7 67 if (!val)
Sissors 1:f8b4b764ace7 68 rx_error = true;
Sissors 1:f8b4b764ace7 69
Sissors 1:f8b4b764ace7 70 if (!rx_error) {
Sissors 1:f8b4b764ace7 71 out_valid = true;
Sissors 1:f8b4b764ace7 72 out_buffer = read_buffer;
Sissors 1:f8b4b764ace7 73 }
Sissors 1:f8b4b764ace7 74 read_buffer = 0;
Sissors 1:f8b4b764ace7 75 rxout.detach();
Sissors 1:f8b4b764ace7 76 rx->fall(this, &SoftSerial::rx_gpio_irq_handler);
Sissors 1:f8b4b764ace7 77 }
Sissors 1:f8b4b764ace7 78