--- /dev/null
+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 David Prentice (david.prentice [at] farming [dot] uk)\r
+ Copyright 2009 Peter Danneger\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+#include "SoftUART.h"\r
+\r
+volatile uint8_t srx_done, stx_count;\r
+volatile uint8_t srx_data, srx_mask, srx_tmp, stx_data;\r
+\r
+unsigned char SoftUART_IsReady(void)\r
+{\r
+ return !(stx_count);\r
+}\r
+\r
+unsigned char SoftUART_TxByte(unsigned char c)\r
+{\r
+ while (stx_count);\r
+\r
+ stx_data = ~c;\r
+ stx_count = 10;\r
+\r
+ return c;\r
+}\r
+\r
+unsigned char SoftUART_IsReceived(void)\r
+{\r
+ return srx_done;\r
+}\r
+\r
+unsigned char SoftUART_RxByte(void)\r
+{\r
+ while (!(srx_done));\r
+\r
+ srx_done = 0;\r
+\r
+ return srx_data;\r
+}\r
+\r
+void SoftUART_Init(void)\r
+{\r
+ OCR2B = TCNT2 + 1; // force first compare\r
+ TCCR2A = (1 << COM2B1) | (1 << COM2B0); // T1 mode 0\r
+ TCCR2B = (1 << FOC2B) | (1 << CS21); // CLK/8, T1 mode 0\r
+ TIMSK2 = (1 << OCIE2B); // enable tx and wait for start\r
+ EICRA = (1 << ISC01); // -ve edge\r
+ EIMSK = (1 << INT0); // enable INT0 interrupt\r
+\r
+ stx_count = 0; // nothing to send\r
+ srx_done = 0; // nothing received\r
+ STXPORT |= 1 << STX; // TX output\r
+ STXDDR |= 1 << STX; // TX output\r
+ SRXPORT |= (1 << SRX); // pullup on INT0\r
+}\r
+\r
+/* ISR to detect the start of a bit being sent from the transmitter. */\r
+ISR(INT0_vect)\r
+{\r
+ OCR2A = TCNT2 + (BIT_TIME / 8 * 3 / 2); // scan 1.5 bits after start\r
+\r
+ srx_tmp = 0; // clear bit storage\r
+ srx_mask = 1; // bit mask\r
+\r
+ TIFR2 = (1 << OCF2A); // clear pending interrupt\r
+\r
+ if (!(SRXPIN & (1 << SRX))) // still low\r
+ {\r
+ TIMSK2 = (1 << OCIE2A) | (1 << OCIE2B); // wait for first bit\r
+ EIMSK &= ~(1 << INT0);\r
+ }\r
+}\r
+\r
+/* ISR to manage the reception of bits to the transmitter. */\r
+ISR(TIMER2_COMPA_vect)\r
+{\r
+ if (srx_mask)\r
+ {\r
+ if (SRXPIN & (1 << SRX))\r
+ srx_tmp |= srx_mask;\r
+\r
+ srx_mask <<= 1;\r
+\r
+ OCR2A += BIT_TIME / 8; // next bit slice\r
+ }\r
+ else\r
+ {\r
+ srx_done = 1; // mark rx data valid\r
+ srx_data = srx_tmp; // store rx data\r
+ TIMSK2 = (1 << OCIE2B); // enable tx and wait for start\r
+ EIMSK |= (1 << INT0); // enable START irq\r
+ EIFR = (1 << INTF0); // clear any pending\r
+ }\r
+}\r
+\r
+/* ISR to manage the transmission of bits to the receiver. */\r
+ISR(TIMER2_COMPB_vect)\r
+{\r
+ OCR2B += BIT_TIME / 8; // next bit slice\r
+\r
+ if (stx_count)\r
+ {\r
+ if (--stx_count != 9) // no start bit\r
+ {\r
+ if (!(stx_data & 1)) // test inverted data\r
+ TCCR2A = (1 << COM2B1) | (1 << COM2B0);\r
+ else\r
+ TCCR2A = (1 << COM2B1);\r
+\r
+ stx_data >>= 1; // shift zero in from left\r
+ }\r
+ else\r
+ {\r
+ TCCR2A = (1 << COM2B1); // START bit\r
+ }\r
+ }\r
+} \r
--- /dev/null
+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 David Prentice (david.prentice [at] farming [dot] uk)\r
+ Copyright 2009 Peter Danneger\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+#ifndef _SOFT_UART_\r
+#define _SOFT_UART_\r
+\r
+ /* Includes: */\r
+ #include <avr/io.h>\r
+ #include <avr/interrupt.h>\r
+ #include "SoftUART.h"\r
+\r
+ /* Macros: */\r
+ #define BAUD 9600\r
+ #define BIT_TIME (uint16_t)((F_CPU + (BAUD / 2)) / BAUD)\r
+\r
+ #define SRX PD0\r
+ #define SRXPIN PIND\r
+ #define SRXPORT PORTD\r
+\r
+ #define STX PD1\r
+ #define STXPORT PORTD\r
+ #define STXDDR DDRD\r
+\r
+ /* Function Prototypes: */\r
+ unsigned char SoftUART_IsReady(void);\r
+ unsigned char SoftUART_TxByte(unsigned char c);\r
+ unsigned char SoftUART_IsReceived(void);\r
+ unsigned char SoftUART_RxByte(void);\r
+ void SoftUART_Init(void);\r
+\r
+#endif
\ No newline at end of file
projects / pub / USBasp.git / commitdiff