Changed arrangement in ngham_packets.h structs (be careful\!), added …

…NGHam SPP python example, started on NGHam SPP C-code, updated documentation.

.gitignore

@@ -1 +0,0 @@
-ngham_platform.c

README.md

@@ -23,26 +23,30 @@ Content:
 
 | File/folder       | Description |
 |:-----------       |:----------- |
+| documentation/    | More documentation. |
 | fec-3.0.1/        | FEC library by Phil Karn for Reed Solomon. (http://www.ka9q.net/code/fec/) |
-| other/            | More documentation. |
+| platform/         | User provided - MUST BE CUSTOMIZED. |
+| ccsds_scrambler.h | Pre-generated array from scrambling polynomial. |
+| crc_ccitt.h       | CRC-code used in NGHam. |
 | ngham.h           | The main NGHam encoder/decoder functions. |
 | ngham_packets.h   | Declarations of the TX/RX packet structs etc. |
-| ngham_platform.h  | User provided code - MUST BE CUSTOMIZED. |
-| crc_ccitt.h       | CRC-code used in NGHam. |
-| ccsds_scrambler.h | Pre-generated array from scrambling polynomial. |
+| ngham_paths.h     | User provided - MUST BE CUSTOMIZED. |
+| ngham_spp.h       | Serial port protocol for communication with the host.  |
+| ngham_spp_test.py | Python code for NGHAM SPP communication. |
+
 
 Not finished:
 
 | File/folder       | Description |
 |:-----------       |:----------- |
 | ngham_extensions.h        | An extension of the payload field in the NGHam radio protocol (enabled by a flag in the NGHam header).  |
-| ngham_spp.h            | Serial port protocol for communication with the host.  |
 
-Usage:
+Usage (for NGHam RF protocol):
 
 1. Provide your own sync word correlator and GMSK (de)modulator. 
 2. The demodulator should start outputting data only after sync word is detected.
-3. ngham_platform.h/c must be customized for the platform you are using.
+3. Build all files in the root except "ngham_spp.c". From the folder "fec-3.0.1", build "decode_rs_char.c", "encode_rs_char.c" and "init_rs_char.c".
+3. "ngham_paths.h" and the code in "platform/" must be customized.
 
 ```
 // Initialize Reed Solomon arrays - only do this once!

other/sketchbooks_(for_own_reference)/ngham_extension_preliminary.txt → documentation/sketchbooks_(for_own_reference)/ngham_extension_preliminary.txt

@@ -4,29 +4,28 @@ Multple types of data can be fitted inside a NGHam packet, by starting with a ne
 
 Extension data types:
 0x00 Binary data of unknown type
-0x01 Address
+0x01 Ham address - everything after an adress belongs to the transmitting station
 0x02 Statistics
 0x03 Statistics for timing reference
 0x04 Position
 0x05 Voice
 0x06 JPEG image
+0x07 Repeated ham adress (originates from another station)
 
 ** Address **
-Size is 6-17 B - eg. LA3JPA to broadcast will be 10 B, LA1K to broadcast is 8B, LA1K123Y to LA1K100Y is 17B
- * 2-7B source: 4 bit LEN (1-8), 4 bit SSID, LEN x 6 bit (chars), fill to n*8 - LA3JPA-3
- * 1-7B destination: 4 bit LEN (0-8, 0=broadcast), 4 bit SSID, LEN x 6 bit (chars), fill to n*8 - LA3JPA-3
+Size is 6-17 B - eg. LA3JPA to broadcast will be 8B, LA1K to broadcast is 6B, LA1K123Y to LA1K100Y is 16B
+ * 2-7B mycall: 4 bit LEN (1-8), 4 bit SSID, LEN x 6 bit (chars), fill to n*8 - LA3JPA-3
  * 1B sequence number
- * 1B extended fields, packet type:
+ * 1B fields, packet type:
+     1b destcall_en - if this is not a broadcast packet, insert destination callsign
      1b hopping_field_en
      1b timeslot_field_en
      1b connected_field_en
- * 1B hopping: 1b reserved, 1b add_path_trace, 1b fill_in_hop_finished, 1b fill_in_hop_left, 2b hops_finished, 2b hops_left
-     If path_trace_en is set, fill_in_hops_finished+hops_finished callsigns follow (maximum 4):
-     2-7B: 4 bit LEN (1-8), 4 bit SSID, LEN x 6 bit (chars), fill to n*8 - LA3JPA-3
+ * 1-7B destcall: 4 bit LEN (1-8), 4 bit SSID, LEN x 6 bit (chars), fill to n*8 - LA3JPA-3
+ * 1B hopping: 2b reserved, 1b fill_in_hop_finished, 1b fill_in_hop_total, 2b hops_finished, 2b hops_total (not including fill-in)
  * 2B timeslot information
  * 1B connected mode information: 0=cts, 1=rts, 2=ack, 3=nack
 
-
 ** Position **
 If address is enabled, use broadcast. Address size will therefore be 11 B.
 Wait one full timeslot period to generate adress book, then picks random free timeslot
@@ -47,3 +46,9 @@ Takes less than 140 ms to transmit at 4800 baud. Will fit in 60 B payload size w
  * Comment
  * Icon
 ( * 2B timeslot information: 12b first timeslot, 4 b timeslot modulo (transmits every 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024) )
+
+
+Repeated packet:
+Address
+Repeated address
+Position

ngham.c

@@ -5,14 +5,17 @@
 
 #include "ngham.h"
 
-#include "fec-3.0.1/char.h"			// Reed Solomon code from Phil Karn
-#include "fec-3.0.1/rs-common.h"
+#include "fec-3.0.1/fec.h"			// RS code from Phil Karn
+#include "fec-3.0.1/char.h"			// RS code specific to 8-bit symbol size
+#include "fec-3.0.1/rs-common.h"	// RS control block struct
 #include <stddef.h>					// For NULL etc.
 #include <string.h>					// For memcpy
 #include "ccsds_scrambler.h"		// Pre-generated array from scrambling polynomial
 #include "ngham_packets.h"			// Structs for TX and RX packets
 #include "crc_ccitt.h"
-#include "ngham_platform.h"				// CRC-code
+
+#include "ngham_paths.h"
+#include PATH_NGHAM_PLATFORM
 
 // There are seven different sizes.
 // Each size has a correlation tag for size, a total size, a maximum payload size and a parity data size.
@@ -141,7 +144,7 @@ void ngham_decode(uint8_t d){
 	static uint32_t size_tag;
 
 	switch (decoder_state){
-
+		
 		case NGH_STATE_SIZE_TAG:
 			size_tag = 0;
 			ngham_action_reception_started();

ngham_packets.c

@@ -12,4 +12,5 @@ void rx_pkt_init(rx_pkt_t *p){
 void tx_pkt_init(tx_pkt_t *p){
 	p->pl_len = 0;
 	p->ngham_flags = 0;
+	p->priority = PKT_PRIORITY_NORMAL;
 }

ngham_packets.h

@@ -27,23 +27,33 @@
 // If the following flag is set in a packet, NGHam extensions are used and first byte is type
 #define NGHAM_FLAG_TYPE_EXTENSION	0x01
 
-typedef struct{
+#define SPP_PL_MAX 512
+
+typedef struct __attribute__ ((packed)){
+	uint32_t timestamp;		// Time stamp of sync word detection
 	uint16_t pl_len;
-	uint8_t pl[PKT_PL_SIZE];
-	uint8_t ngham_flags;
-	uint8_t rssi;			// In dBm + 200
 	uint8_t noise;			// Same as above
+	uint8_t rssi;			// In dBm + 200
 	uint8_t errors;			// Recovered symbols
-	uint32_t timestamp;		// Time stamp of sync word detection
+	uint8_t ngham_flags;
+	uint8_t pl[PKT_PL_SIZE];
 }rx_pkt_t;
 
-typedef struct{
+typedef struct __attribute__ ((packed)){
 	uint16_t pl_len;
-	uint8_t pl[PKT_PL_SIZE];
-	uint8_t ngham_flags;
 	uint8_t priority;
+	uint8_t ngham_flags;
+	uint8_t pl[PKT_PL_SIZE];
 }tx_pkt_t;
 
+// NGHam SPP header
+typedef struct __attribute__ ((packed)){
+	uint8_t start;
+	uint16_t crc;
+	uint8_t pl_type;
+	uint8_t pl_len;
+}ngh_spphdr_t;
+
 void rx_pkt_init(rx_pkt_t *p);
 void tx_pkt_init(tx_pkt_t *p);
 

ngham_paths.h

@@ -0,0 +1,7 @@
+// Path to main NGHAM platform specific code
+#define PATH_NGHAM_PLATFORM "c:/lagring/prosjekter/owl_vhf/firmware/ngham_owl_platform.h"
+// #define PATH_NGHAM_PLATFORM "platform/platform.h"
+
+// Path to NGHAM serial port protocol platform code
+#define PATH_NGHAM_PLATFORM_SPP "c:/lagring/prosjekter/owl_vhf/firmware/ngham_owl_platform_spp.h"
+// #define PATH_NGHAM_PLATFORM_SPP "platform/platform_spp.h"

ngham_spp.c

@@ -0,0 +1,103 @@
+//**************************************************************//
+// NGHam protocol - Jon Petter Skagmo, LA3JPA, 2014.            //
+// Licensed under LGPL.                                         //
+//**************************************************************//
+
+#include "ngham_packets.h"
+#include "crc_ccitt.h"
+
+#include "ngham_paths.h"
+#include PATH_NGHAM_PLATFORM_SPP
+
+#define SPP_START			0x24	// Packet start byte definition
+
+#define SPP_STATE_START 	0x00	// States
+#define SPP_STATE_HEADER	0x01
+#define SPP_STATE_PAYLOAD	0x02
+
+#define SPP_TYPE_RF			0x00	// Packet types
+#define SPP_TYPE_LOCAL		0x01
+#define SPP_TYPE_CMD		0x02
+
+void ngham_pack_byte(port_ctx_t* ctx, uint8_t c){
+	switch(ctx->state){
+		case SPP_STATE_START:
+			if (c == SPP_START){
+				ctx->state = SPP_STATE_HEADER;	// Start found; go to next state
+				ctx->d_ip = 1;	// Starts at next first as SPP_START is already received
+			}
+			break;
+
+		case SPP_STATE_HEADER:
+			((uint8_t*)&ctx->ngh_spp)[ctx->d_ip++] = c;	// Fill header
+			if (ctx->d_ip >= sizeof(ngh_spphdr_t)){
+				ctx->d_ip = 0;
+				ctx->state = SPP_STATE_PAYLOAD;
+			}
+			break;
+
+		case SPP_STATE_PAYLOAD:
+			if (ctx->d_ip < PORT_BUF_SIZE) ctx->d[ctx->d_ip++] = c;	// Fill ctx->d with payload
+			if (ctx->d_ip >= ctx->ngh_spp.pl_len){
+				ctx->state = SPP_STATE_START;
+
+				// Calc CRC of type, length and payload
+				int j;
+				uint16_t crc = 0xffff;
+				for (j=3; j<5; j++) crc = crc_ccitt_byte(((uint8_t*)&ctx->ngh_spp)[j], crc);
+				for (j=0; j<ctx->d_ip; j++) crc = crc_ccitt_byte(ctx->d[j], crc);
+				crc ^= 0xffff;
+				if (crc == ctx->ngh_spp.crc){
+					switch(ctx->ngh_spp.pl_type){
+						case SPP_TYPE_RF:
+							{
+								// Data to be sent
+								tx_pkt_t p;
+								tx_pkt_init(&p);
+								p.ngham_flags = ctx->d[0];	// First byte in NGH SPP RF type is flags
+								p.pl_len = ctx->d_ip-1;
+								for (j=0; j<p.pl_len; j++) p.pl[j] = ctx->d[j+1];
+								PACKER_CALL(&p);
+
+								// TODO: Generate response!
+							}
+							break;
+						case SPP_TYPE_CMD:
+							{
+								// Prepare command and response
+								ngh_spphdr_t hdr;
+								uint8_t r[sizeof(hdr)+SPP_PL_MAX];
+								hdr.start = SPP_START;
+								hdr.pl_type = SPP_TYPE_CMD;
+								hdr.pl_len = 0;
+								cmd(ctx->d, ctx->ngh_spp.pl_len, &r[sizeof(hdr)], &hdr.pl_len);	// Run command
+								for (j=3; j<5; j++) r[j] = ((uint8_t*)&hdr)[j];		// Copy length and type into header
+								hdr.crc = crc_ccitt(&r[3], hdr.pl_len+2);
+								for (j=0; j<3; j++) r[j] = ((uint8_t*)&hdr)[j];		// Copy CRC and stat into header
+								port_output(ctx, r, sizeof(hdr)+hdr.pl_len);		// Send to port
+							}
+							break;
+					}
+				}
+			}
+			break;
+	}
+}
+
+void ngham_unpack(rx_pkt_t* p){
+	int j;
+	ngh_spphdr_t hdr;
+	hdr.start = SPP_START;
+	hdr.crc = 0xffff;
+	hdr.pl_type = SPP_TYPE_RF;
+	hdr.pl_len = p->pl_len+4;
+
+	// Calc CRC
+	for (j=3; j<5; j++) hdr.crc = crc_ccitt_byte(((uint8_t*)&hdr)[j], hdr.crc);
+	for (j=0; j<hdr.pl_len; j++) hdr.crc = crc_ccitt_byte(((uint8_t*)&p->noise)[j], hdr.crc);	// SPP-protocol must match with rx_pkt_t struct
+	hdr.crc ^= 0xffff;
+
+	// Copy remaining and send to port
+	UNPACKER_CALL(PACKER_NGHAM, (uint8_t*)&hdr, sizeof(ngh_spphdr_t));
+	UNPACKER_CALL(PACKER_NGHAM, (uint8_t*)&p->noise, hdr.pl_len);
+}

ngham_spp.h

@@ -3,3 +3,10 @@
 // Licensed under LGPL.                                         //
 //**************************************************************//
 
+#include <stdint.h>
+
+#include "ngham_paths.h"
+#include PATH_NGHAM_PLATFORM_SPP
+
+void ngham_pack_byte(port_ctx_t* ctx, uint8_t c);
+void ngham_unpack(rx_pkt_t* p);