add initial ootx decoder

6 files changed, 392 insertions, 0 deletions

diff --git a/tools/ootx_decode/HMD_Datagen.c b/tools/ootx_decode/HMD_Datagen.c
new file mode 100644
index 0000000..d71d291
--- /dev/null
+++ b/tools/ootx_decode/HMD_Datagen.c
@@ -0,0 +1,99 @@
+// (C) 2016 Joshua Allen, MIT/x11 License.
+//
+//All MIT/x11 Licensed Code in this file may be relicensed freely under the GPL or LGPL licenses.
+
+/* generate data to test ootx decoding */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <time.h>
+#include <stdlib.h>
+
+uint32_t time_stamp = -525198892;
+
+char* fmt_str = "L Y HMD %d 5 1 206230 %d\n";
+
+void print_bit(uint8_t data);
+void print_preamble();
+void print_uint16(uint16_t d);
+void print_uint32(uint32_t d);
+void print_payload(char* data, uint16_t length);
+uint32_t crc32(uint32_t crc, uint8_t *buf, size_t size);
+
+int main(int argc, char* argv[])
+{
+	char* str = "Hello World!";
+//	printf("%s\n", str);
+
+	srand(time(NULL));
+
+	print_preamble();
+
+	uint16_t payload_lenth = strlen(str);
+	uint32_t crc = crc32(0xffffffff,(uint8_t*)str,payload_lenth);
+
+	print_uint16(payload_lenth);
+	print_payload(str,payload_lenth);
+	print_uint32(crc);
+
+	return 0;
+}
+
+void print_preamble() {
+	int i;
+	for (i=0;i<17;++i) print_bit(0);
+	print_bit(1);
+}
+
+void print_uint16(uint16_t d) {
+	int i;
+	for (i=0;i<16;++i) {
+		print_bit(d & 0x0001);
+		d>>=1;
+	}
+	print_bit(1);
+}
+
+void print_uint32(uint32_t d) {
+	int i = 0;
+	for (;i<16;++i) {
+		print_bit(d & 0x01);
+		d>>=1;
+	}
+	print_bit(1);
+
+	for (;i<32;++i) {
+		print_bit(d & 0x01);
+		d>>=1;
+	}
+	print_bit(1);
+}
+
+void print_payload(char* data, uint16_t length) {
+	int i;
+	for(i=0;i<length;i+=2) {
+		uint16_t d = *((uint16_t*)(data+i));
+//		printf("%d\n", d);
+		print_uint16(d);
+	}
+}
+
+void print_bit(uint8_t data) {
+	uint32_t length = 3000 + (rand()%2)*500 + data*1000 + (rand()%2)*2000;
+	length -= rand()%500;
+	printf(fmt_str, time_stamp, length);
+
+	time_stamp++;
+
+	/*
+	//to decode
+	// 3000 + x*500 + dbit*1000 + y*2000
+	length -= 3000;
+	if (length>=2000) { length-=2000; y = 0x01; }
+	if (length>=1000)  { length-=1000; dbit = 0x01; }
+	if (length>=500)  { x = 0x01; }
+	*/
+
+	//fire off a callback when a full OOTX packet is received
+}
\ No newline at end of file
diff --git a/tools/ootx_decode/Makefile b/tools/ootx_decode/Makefile
new file mode 100644
index 0000000..f72cbb5
--- /dev/null
+++ b/tools/ootx_decode/Makefile
@@ -0,0 +1,7 @@
+all: ootx_decode hmd_datagen
+
+hmd_datagen: HMD_Datagen.c crc32.c
+	gcc -Wall HMD_Datagen.c crc32.c -o hmd_datagen
+
+ootx_decode: ootx_decode.c ootx_decoder.c ootx_decoder.h
+	gcc -Wall ootx_decode.c ootx_decoder.c -o ootx_decode
\ No newline at end of file
diff --git a/tools/ootx_decode/crc32.c b/tools/ootx_decode/crc32.c
new file mode 100644
index 0000000..a719cbf
--- /dev/null
+++ b/tools/ootx_decode/crc32.c
@@ -0,0 +1,103 @@
+/*-
+ *  COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or
+ *  code or tables extracted from it, as desired without restriction.
+ *
+ *  First, the polynomial itself and its table of feedback terms.  The
+ *  polynomial is
+ *  X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
+ *
+ *  Note that we take it "backwards" and put the highest-order term in
+ *  the lowest-order bit.  The X^32 term is "implied"; the LSB is the
+ *  X^31 term, etc.  The X^0 term (usually shown as "+1") results in
+ *  the MSB being 1
+ *
+ *  Note that the usual hardware shift register implementation, which
+ *  is what we're using (we're merely optimizing it by doing eight-bit
+ *  chunks at a time) shifts bits into the lowest-order term.  In our
+ *  implementation, that means shifting towards the right.  Why do we
+ *  do it this way?  Because the calculated CRC must be transmitted in
+ *  order from highest-order term to lowest-order term.  UARTs transmit
+ *  characters in order from LSB to MSB.  By storing the CRC this way
+ *  we hand it to the UART in the order low-byte to high-byte; the UART
+ *  sends each low-bit to hight-bit; and the result is transmission bit
+ *  by bit from highest- to lowest-order term without requiring any bit
+ *  shuffling on our part.  Reception works similarly
+ *
+ *  The feedback terms table consists of 256, 32-bit entries.  Notes
+ *
+ *      The table can be generated at runtime if desired; code to do so
+ *      is shown later.  It might not be obvious, but the feedback
+ *      terms simply represent the results of eight shift/xor opera
+ *      tions for all combinations of data and CRC register values
+ *
+ *      The values must be right-shifted by eight bits by the "updcrc
+ *      logic; the shift must be unsigned (bring in zeroes).  On some
+ *      hardware you could probably optimize the shift in assembler by
+ *      using byte-swap instructions
+ *      polynomial $edb88320
+ *
+ *
+ * CRC32 code derived from work by Gary S. Brown.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+static uint32_t crc32_tab[] = {
+	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+	0xe963a535, 0x9e6495a3,	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+	0xf3b97148, 0x84be41de,	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,	0x14015c4f, 0x63066cd9,
+	0xfa0f3d63, 0x8d080df5,	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,	0x35b5a8fa, 0x42b2986c,
+	0xdbbbc9d6, 0xacbcf940,	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,	0x76dc4190, 0x01db7106,
+	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+uint32_t crc32(uint32_t crc, const void *buf, size_t size)
+{
+	const uint8_t *p;
+
+	p = buf;
+	crc = crc ^ ~0U;
+
+	while (size--)
+		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
+
+	return crc ^ ~0U;
+}
diff --git a/tools/ootx_decode/ootx_decode.c b/tools/ootx_decode/ootx_decode.c
new file mode 100644
index 0000000..803b39e
--- /dev/null
+++ b/tools/ootx_decode/ootx_decode.c
@@ -0,0 +1,50 @@
+// (C) 2016 Joshua Allen, MIT/x11 License.
+//
+//All MIT/x11 Licensed Code in this file may be relicensed freely under the GPL or LGPL licenses.
+
+/* ootx data decoder test*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+
+#include "ootx_decoder.h"
+
+//char* fmt_str = "L Y HMD %d 5 1 206230 %d\n";
+//extern std::istream cin;
+
+void my_test(ootx_packet* packet) {
+	packet->data[packet->length] = 0;
+	printf("%d %s 0x%X\n", packet->length, packet->data, packet->crc32);
+}
+
+int main(int argc, char* argv[])
+{
+	ootx_init_buffer();
+	ootx_packet_clbk = my_test;
+
+	char* line = NULL;
+	size_t line_len = 0;
+	char trash[100] = "";
+	uint32_t ticks = 0x00;
+
+	while (getline(&line,&line_len,stdin)>0) {
+//		printf("%s\n", line);
+		sscanf(line,"%s %s %s %s %s %s %s %d",
+			trash,
+			trash,
+			trash,
+			trash,
+			trash,
+			trash,
+			trash,
+			&ticks);
+//		printf("%d\n", ticks);
+
+		ootx_process_bit(ticks);
+	}
+
+	return 0;
+}
\ No newline at end of file
diff --git a/tools/ootx_decode/ootx_decoder.c b/tools/ootx_decode/ootx_decoder.c
new file mode 100644
index 0000000..70a88b5
--- /dev/null
+++ b/tools/ootx_decode/ootx_decoder.c
@@ -0,0 +1,112 @@
+// (C) 2016 Joshua Allen, MIT/x11 License.
+//
+//All MIT/x11 Licensed Code in this file may be relicensed freely under the GPL or LGPL licenses.
+
+/* ootx data decoder */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <assert.h>
+#include "ootx_decoder.h"
+
+//char* fmt_str = "L Y HMD %d 5 1 206230 %d\n";
+
+#define MAX_BUFF_SIZE 1024
+uint8_t* buffer = NULL;
+uint16_t buf_offset = 0;
+uint8_t bits_written = 0;
+uint16_t* payload_size = NULL;
+
+void (*ootx_packet_clbk)(ootx_packet* packet) = NULL;
+
+void ootx_init_buffer() {
+	buffer = (uint8_t*)malloc(MAX_BUFF_SIZE);
+	payload_size = (uint16_t*)buffer;
+	*payload_size = 0;
+}
+
+uint8_t ootx_decode_bit(uint32_t length) {
+	length = ((length/500)*500)+500;
+
+	length-=3000;
+	if (length>=2000) { length-=2000; }
+	if (length>=1000)  { return 0x01; }
+
+	return 0x00;
+}
+
+uint8_t ootx_detect_preamble(uint8_t dbit) {
+	static uint32_t preamble = 0x00;
+	preamble <<= 1;
+	preamble |= dbit;
+	if ((preamble & 0x0001ffff) == 0x01) return 1;
+	return 0;
+}
+
+void ootx_reset_buffer() {
+	buf_offset = 0;
+	buffer[buf_offset] = 0;
+	bits_written = 0;
+	*payload_size = 0;
+}
+
+void ootx_inc_buffer_offset() {
+	++buf_offset;
+//	if (buf_offset>=MAX_BUFF_SIZE) buf_offset = 0;
+	assert(buf_offset<MAX_BUFF_SIZE);
+	buffer[buf_offset] = 0;
+}
+
+void ootx_write_to_buffer(uint8_t dbit) {
+	uint8_t *current_byte = buffer+buf_offset;
+//	printf("%d\n", dbit);
+	*current_byte >>= 1;
+	*current_byte |= (0x80 * dbit);
+	++bits_written;
+	if (bits_written>7) {
+		bits_written=0;
+//		printf("%d\n", *current_byte);
+		ootx_inc_buffer_offset();
+	}
+}
+
+void ootx_process_bit(uint32_t length) {
+	static uint8_t bits_processed = 0;
+
+	uint8_t dbit = ootx_decode_bit(length);
+	++bits_processed;
+
+//	printf("z %d %d\n", bits_processed,dbit);
+//	printf("d %d\n", bits_processed,dbit);
+
+	if ( ootx_detect_preamble(dbit) ) {
+		/*	data stream can start over at any time so we must
+			always look for preamble bits */
+//		printf("Preamble found\n");
+		ootx_reset_buffer();
+		bits_processed = 0;
+	}
+	else if(bits_processed>16) {
+		//every 17th bit needs to be dropped
+//		printf("drop %d\n", dbit);
+		bits_processed = 0;
+	}
+	else
+	{
+		ootx_write_to_buffer(dbit);
+
+		if (buf_offset >= (*payload_size+6)) {
+			/*	once we have a complete ootx packet, send it out in the callback */
+			ootx_packet op;
+
+			op.length = *(uint16_t*)buffer;
+			op.data = buffer+2;
+			op.crc32 = *(uint32_t*)(buffer+2+op.length);
+			if (ootx_packet_clbk) ootx_packet_clbk(&op);
+
+			ootx_reset_buffer();
+		}
+	}
+}
+
diff --git a/tools/ootx_decode/ootx_decoder.h b/tools/ootx_decode/ootx_decoder.h
new file mode 100644
index 0000000..b714b53
--- /dev/null
+++ b/tools/ootx_decode/ootx_decoder.h
@@ -0,0 +1,21 @@
+// (C) 2016 Joshua Allen, MIT/x11 License.
+//
+//All MIT/x11 Licensed Code in this file may be relicensed freely under the GPL or LGPL licenses.
+
+#ifndef OOTX_DECODER_H
+#define OOTX_DECODER_H
+
+#include <stdint.h>
+
+typedef struct {
+	uint16_t length;
+	uint8_t* data;
+	uint32_t crc32;
+} ootx_packet;
+
+void ootx_init_buffer();
+void ootx_process_bit(uint32_t length);
+
+extern void (*ootx_packet_clbk)(ootx_packet* packet);
+
+#endif
\ No newline at end of file