eth_comfort_freebus - Program for decoding radio-signals sent by a ETH-…

Users » charly » Code » eth_comfort_freebus

Karl Zweimüller / Mbed 2 deprecated eth_comfort_freebus

Program for decoding radio-signals sent by a ETH-Window-Shutter-Contact, received with a RFM12B-module. The messages are sent to KNX via a freebus rs-interface. Details see http://mbed.org/users/charly/notebook/connecting-a-radio-window-shutter-contact-to-knx/

Dependencies: TextLCD mbed ConfigFile

eth_comfort.cpp@0:b79cb3278583, 2011-04-27 (annotated)

Committer:: charly
Date:: Wed Apr 27 19:02:00 2011 +0000
Revision:: 0:b79cb3278583

Who changed what in which revision?

User	Revision	Line number	New contents of line
charly	0:b79cb3278583	1	/** module for receiving data from eth comfort window sensor by ELV(R) with a RFM12 transceiver module by Hope
charly	0:b79cb3278583	2
charly	0:b79cb3278583	3	Details see discussion on http://www.mikrocontroller.net/topic/172034
charly	0:b79cb3278583	4	Frequenz 868,3
charly	0:b79cb3278583	5	Modulation FSK
charly	0:b79cb3278583	6	Hub +/- 15kHz
charly	0:b79cb3278583	7	Datenrate 10kbit Manchester
charly	0:b79cb3278583	8
charly	0:b79cb3278583	9	das Protokoll ist Machester codiert
charly	0:b79cb3278583	10	0x7e zz ll aa aa aa cmd crc crc
charly	0:b79cb3278583	11
charly	0:b79cb3278583	12	zz ist ein fortlaufender Zaehler
charly	0:b79cb3278583	13	ll die Blocklaenge 10,20,30 (20 = 9 Byte, 10= 10Byte ,30= ?)
charly	0:b79cb3278583	14	aa 3 Byte Adresse
charly	0:b79cb3278583	15	cmd der Befehl
charly	0:b79cb3278583	16	crc 16 bit checksumme
charly	0:b79cb3278583	17
charly	0:b79cb3278583	18	die Reihenfolge der Bits im Byte ist verdreht.
charly	0:b79cb3278583	19
charly	0:b79cb3278583	20	*/
charly	0:b79cb3278583	21	/*!
charly	0:b79cb3278583	22	* \file eth_comfort.cpp
charly	0:b79cb3278583	23	* \brief Read the messages from the ETH-Radio-Shutter
charly	0:b79cb3278583	24	* \author Karl Zweimüller based on code from WED 6.9.2009
charly	0:b79cb3278583	25	*/
charly	0:b79cb3278583	26
charly	0:b79cb3278583	27
charly	0:b79cb3278583	28	#include "eth_comfort.h"
charly	0:b79cb3278583	29
charly	0:b79cb3278583	30	/* orig AVR-values
charly	0:b79cb3278583	31	#define BIT_MAX 0x90
charly	0:b79cb3278583	32	#define BIT_MIN 0x10
charly	0:b79cb3278583	33	#define LEN_2T 0x44
charly	0:b79cb3278583	34	*/
charly	0:b79cb3278583	35
charly	0:b79cb3278583	36	//working: 300-80-200
charly	0:b79cb3278583	37	// nominal values are: 208-104-208 for 9600 bits/sec
charly	0:b79cb3278583	38	#define BIT_MAX 300 // maximum allowed time for one or two bits high or low
charly	0:b79cb3278583	39	#define BIT_MIN 80 // minimum allowed time for one or two bits high or low
charly	0:b79cb3278583	40	#define LEN_2T 200 // time-value to differentiate one or two bit length
charly	0:b79cb3278583	41
charly	0:b79cb3278583	42
charly	0:b79cb3278583	43	// Timer for bit-length-measurement
charly	0:b79cb3278583	44	Timer BitTime;
charly	0:b79cb3278583	45
charly	0:b79cb3278583	46
charly	0:b79cb3278583	47	eth_comfort::eth_comfort(PinName mosi, PinName miso, PinName sclk, PinName nsel, PinName rxdata, PinName rxled) {
charly	0:b79cb3278583	48
charly	0:b79cb3278583	49	rfm12b_spi = new rfm12b(mosi,miso,sclk,nsel,rxdata);
charly	0:b79cb3278583	50
charly	0:b79cb3278583	51	// the ReceiveLED
charly	0:b79cb3278583	52	rxLED = new DigitalOut(rxled);
charly	0:b79cb3278583	53
charly	0:b79cb3278583	54	// init the eth_receiver
charly	0:b79cb3278583	55	init();
charly	0:b79cb3278583	56
charly	0:b79cb3278583	57	// Interrupt on every bit-change
charly	0:b79cb3278583	58	rfm12b_spi->attachISR(this, &eth_comfort::ISR);
charly	0:b79cb3278583	59
charly	0:b79cb3278583	60	// Init the RFM12B
charly	0:b79cb3278583	61	rfm12b_spi->RFM_init();
charly	0:b79cb3278583	62
charly	0:b79cb3278583	63	};
charly	0:b79cb3278583	64	//-------------------------------------------------------------------------
charly	0:b79cb3278583	65	// calcCRC16r()
charly	0:b79cb3278583	66	//-------------------------------------------------------------------------
charly	0:b79cb3278583	67	/**
charly	0:b79cb3278583	68	* @brief calculate reverse CRC
charly	0:b79cb3278583	69	* @param c 16bit value for crc
charly	0:b79cb3278583	70	* @param crc old crc value
charly	0:b79cb3278583	71	* @param mask crc polynom
charly	0:b79cb3278583	72	* @return crc value
charly	0:b79cb3278583	73	*/
charly	0:b79cb3278583	74	uint16_t eth_comfort::calcCRC16r( uint16_t c,uint16_t crc, uint16_t mask) { // reverse crc!!!!!!
charly	0:b79cb3278583	75	uint8_t i;
charly	0:b79cb3278583	76	for (i=0;i<8;i++) {
charly	0:b79cb3278583	77	if ((crc ^ c) & 1) {
charly	0:b79cb3278583	78	crc=(crc>>1)^mask;
charly	0:b79cb3278583	79	} else crc>>=1;
charly	0:b79cb3278583	80	c>>=1;
charly	0:b79cb3278583	81	};
charly	0:b79cb3278583	82	return(crc);
charly	0:b79cb3278583	83	}
charly	0:b79cb3278583	84
charly	0:b79cb3278583	85	// initialize eth_receiver
charly	0:b79cb3278583	86	void eth_comfort::init() {
charly	0:b79cb3278583	87
charly	0:b79cb3278583	88	rbyte=0;
charly	0:b79cb3278583	89	bit_cnt=0;
charly	0:b79cb3278583	90	buffer_cnt=0;
charly	0:b79cb3278583	91	decode=0;
charly	0:b79cb3278583	92	pack_ok=0;
charly	0:b79cb3278583	93
charly	0:b79cb3278583	94	// start timer for bit-length-measurement
charly	0:b79cb3278583	95	BitTime.start();
charly	0:b79cb3278583	96	message_received = false;
charly	0:b79cb3278583	97	// init the buffer
charly	0:b79cb3278583	98	last_message.cnt = 0;
charly	0:b79cb3278583	99	last_message.len = 0;
charly	0:b79cb3278583	100	last_message.adr = 0;
charly	0:b79cb3278583	101	last_message.cmd = 0;
charly	0:b79cb3278583	102	last_message.data = 0;
charly	0:b79cb3278583	103	last_message.xdata = 0;
charly	0:b79cb3278583	104	last_message.crc = 0;
charly	0:b79cb3278583	105
charly	0:b79cb3278583	106	new_message = last_message;
charly	0:b79cb3278583	107	}
charly	0:b79cb3278583	108
charly	0:b79cb3278583	109
charly	0:b79cb3278583	110	// is a new message readable
charly	0:b79cb3278583	111	bool eth_comfort::readable() {
charly	0:b79cb3278583	112	return(message_received);
charly	0:b79cb3278583	113	}
charly	0:b79cb3278583	114
charly	0:b79cb3278583	115	// read a eth-messsage
charly	0:b79cb3278583	116	eth_message eth_comfort::getMessage() {
charly	0:b79cb3278583	117	if (readable()) {
charly	0:b79cb3278583	118	last_message = new_message;
charly	0:b79cb3278583	119	message_received = false;
charly	0:b79cb3278583	120	return(new_message);
charly	0:b79cb3278583	121	} else
charly	0:b79cb3278583	122	// we should return nothing here!
charly	0:b79cb3278583	123	return(last_message);
charly	0:b79cb3278583	124	}
charly	0:b79cb3278583	125
charly	0:b79cb3278583	126	/** ISR Interrupt routine for received data
charly	0:b79cb3278583	127	* triggers on every pin change high/low and low/high
charly	0:b79cb3278583	128	* does all the encoding of the signal including manchester decoding!
charly	0:b79cb3278583	129	* as the eth doesn't send a good signal, which the rfm12 could decode for himself
charly	0:b79cb3278583	130	* didn't test for myself - just got the code from someone else and ported to mbed!
charly	0:b79cb3278583	131	*/
charly	0:b79cb3278583	132	void eth_comfort::ISR() { // pin change on rxin ->interrupt
charly	0:b79cb3278583	133	//led2=!led2;
charly	0:b79cb3278583	134	b=BitTime.read_us(); // time since last change
charly	0:b79cb3278583	135	BitTime.reset();
charly	0:b79cb3278583	136
charly	0:b79cb3278583	137	if ((b>BIT_MAX)\|\|(b<BIT_MIN)) { // is bit time in range?
charly	0:b79cb3278583	138	state=0;
charly	0:b79cb3278583	139	} else {
charly	0:b79cb3278583	140
charly	0:b79cb3278583	141
charly	0:b79cb3278583	142	if (state==0) { // wait for first bitchange 2T
charly	0:b79cb3278583	143	if (b>LEN_2T)state=1;
charly	0:b79cb3278583	144	//if((rxin)!=0)state=0; // level should be low
charly	0:b79cb3278583	145	} else if (state<=10) { // wait for 5 fullbit without bitchange 10 shortbits
charly	0:b79cb3278583	146	if (b<LEN_2T)state++;
charly	0:b79cb3278583	147	else state=1; // bitchange found back to state 1
charly	0:b79cb3278583	148	} else if (state==11) { // now expecting bitchange (last bit in 7e is 0)
charly	0:b79cb3278583	149	if (b<LEN_2T) {
charly	0:b79cb3278583	150	state=0; // no bitchange -> back to search
charly	0:b79cb3278583	151	};
charly	0:b79cb3278583	152	state=20; // now we found 7e sync finished
charly	0:b79cb3278583	153	rbyte=0x7e; // set shift value to 0
charly	0:b79cb3278583	154	bit_cnt=8; // clear bitcounter
charly	0:b79cb3278583	155	buffer_cnt=0; // clear buffercounter
charly	0:b79cb3278583	156	bcnt=0;
charly	0:b79cb3278583	157	lastbit=0;
charly	0:b79cb3278583	158
charly	0:b79cb3278583	159	} else if (state==20) {
charly	0:b79cb3278583	160	if (b>LEN_2T) { // check for bitchange
charly	0:b79cb3278583	161	if (lastbit!=0) {
charly	0:b79cb3278583	162	rbyte=(rbyte>>1); // last bit was 1 new is 0
charly	0:b79cb3278583	163	bcnt=0;
charly	0:b79cb3278583	164	lastbit=0;
charly	0:b79cb3278583	165	} else {
charly	0:b79cb3278583	166	rbyte=(rbyte>>1)\|0x80; // last bit was 0 new is 1
charly	0:b79cb3278583	167	bcnt++;
charly	0:b79cb3278583	168	lastbit=1;
charly	0:b79cb3278583	169	}
charly	0:b79cb3278583	170	state=20; // fullbit compleate
charly	0:b79cb3278583	171	bit_cnt++; // increase bit counter
charly	0:b79cb3278583	172	} else {
charly	0:b79cb3278583	173	state=21; // bit is halfbit, wait for next halfbit
charly	0:b79cb3278583	174	};
charly	0:b79cb3278583	175	} else if (state==21) { // no bitchange
charly	0:b79cb3278583	176	if (b<LEN_2T) { // next bit must be a halfbit
charly	0:b79cb3278583	177	if (lastbit==0) {
charly	0:b79cb3278583	178	rbyte=(rbyte>>1); // last bit was 0 new is 0
charly	0:b79cb3278583	179	lastbit=0;
charly	0:b79cb3278583	180	bcnt=0;
charly	0:b79cb3278583	181	} else {
charly	0:b79cb3278583	182	rbyte=(rbyte>>1)\|0x80; // last bit was 1 new is 1
charly	0:b79cb3278583	183	lastbit=1;
charly	0:b79cb3278583	184	bcnt++;
charly	0:b79cb3278583	185	}
charly	0:b79cb3278583	186	state=20;
charly	0:b79cb3278583	187	bit_cnt++;
charly	0:b79cb3278583	188	} else {
charly	0:b79cb3278583	189	state=0; // bit is no halfbit -> Manchester violation
charly	0:b79cb3278583	190	// state=20;
charly	0:b79cb3278583	191	};
charly	0:b79cb3278583	192	} else if (state==22) { // after 5 bit 1 skip one bit 0
charly	0:b79cb3278583	193	if (b>LEN_2T) { // check for bitchange (next bit 0)
charly	0:b79cb3278583	194	lastbit=0;
charly	0:b79cb3278583	195	state=20;
charly	0:b79cb3278583	196	} else {
charly	0:b79cb3278583	197
charly	0:b79cb3278583	198	lastbit=1;
charly	0:b79cb3278583	199	//state=11;
charly	0:b79cb3278583	200	state=21;
charly	0:b79cb3278583	201	}
charly	0:b79cb3278583	202	bcnt=0;
charly	0:b79cb3278583	203
charly	0:b79cb3278583	204
charly	0:b79cb3278583	205	}
charly	0:b79cb3278583	206	if (bcnt==5)state=22;
charly	0:b79cb3278583	207
charly	0:b79cb3278583	208	if (bit_cnt>7) { // wait for 8 bits
charly	0:b79cb3278583	209	buf[buffer_cnt]=rbyte; // save value into buffer
charly	0:b79cb3278583	210	if (buffer_cnt<1020) {
charly	0:b79cb3278583	211	buffer_cnt++;
charly	0:b79cb3278583	212	};
charly	0:b79cb3278583	213	pack_ok=1; // set receiveflag
charly	0:b79cb3278583	214	bit_cnt=0; // clear bitcounter
charly	0:b79cb3278583	215	rxLED = ! rxLED; //show received byte
charly	0:b79cb3278583	216	//////////////////////////////////////////////////////////////////////////////////////////////////////////
charly	0:b79cb3278583	217	//here we received another byte
charly	0:b79cb3278583	218
charly	0:b79cb3278583	219	// we have to check if we are ready with the message
charly	0:b79cb3278583	220	if (buffer_cnt>8) {
charly	0:b79cb3278583	221	if (buf[2]==0x10) blocklength=10;
charly	0:b79cb3278583	222	else if (buf[2]==0x20) blocklength=9;
charly	0:b79cb3278583	223	else blocklength=99;
charly	0:b79cb3278583	224	j=0;
charly	0:b79cb3278583	225	crc_ok = false;
charly	0:b79cb3278583	226	for (i=0;i<=buffer_cnt;i++) {
charly	0:b79cb3278583	227	//pc.printf("%02X ",buf[i]);
charly	0:b79cb3278583	228	j++;
charly	0:b79cb3278583	229	if (j==blocklength) {
charly	0:b79cb3278583	230	//check crc
charly	0:b79cb3278583	231	if (blocklength==9) {
charly	0:b79cb3278583	232	crc=0xbdb7;
charly	0:b79cb3278583	233	for (k=0;k<7;k++) { // crc over first 7 byte
charly	0:b79cb3278583	234	crc=calcCRC16r(buf[k],crc,0x8408);
charly	0:b79cb3278583	235	}
charly	0:b79cb3278583	236	//swap the two crc-bytes
charly	0:b79cb3278583	237	swapped = ((crc >> 8) & 0xff) \| ((crc << 8) & 0xff00);
charly	0:b79cb3278583	238	//pc.printf("CRC: %04X ",swapped);
charly	0:b79cb3278583	239	if (((buf[7]<<8) \| buf[8]) == swapped) crc_ok = true;
charly	0:b79cb3278583	240	else crc_ok = false;
charly	0:b79cb3278583	241	//pc.printf("%s", (crc_ok==true) ? "OK" : "Not OK");
charly	0:b79cb3278583	242	if (crc_ok) {
charly	0:b79cb3278583	243	/*
charly	0:b79cb3278583	244	pc.printf("\n\rCounter: %02X\n\r",buf[1]);
charly	0:b79cb3278583	245	pc.printf( " Dev-ID: %02X %02X %02X\n\r",buf[3],buf[4],buf[5]);
charly	0:b79cb3278583	246	//pc.printf( "Battery: %s\n\r", (buf[6]&0x80 != 0x00) ? "WEAK" : "GOOD");
charly	0:b79cb3278583	247	pc.printf( "Window : %s\n\r\n\r", (buf[6]&0x01 != 0x00) ? "OPEN" : "CLOSE");
charly	0:b79cb3278583	248	lcd.cls();
charly	0:b79cb3278583	249	lcd.printf("#:%02X ID: %02X%02X%02X\n",buf[1],buf[3],buf[4],buf[5]);
charly	0:b79cb3278583	250	lcd.printf("Window : %s\n", (buf[6]&0x01 != 0x00) ? "OPEN" : "CLOSE");
charly	0:b79cb3278583	251	*/
charly	0:b79cb3278583	252
charly	0:b79cb3278583	253	// insert buf into message
charly	0:b79cb3278583	254	new_message.cnt = buf[1];
charly	0:b79cb3278583	255	new_message.len = buf[2];
charly	0:b79cb3278583	256	new_message.adr = buf[3]<<16 \| buf[4]<<8 \| buf[5];
charly	0:b79cb3278583	257	new_message.cmd = buf[6];
charly	0:b79cb3278583	258	new_message.data = buf[7];
charly	0:b79cb3278583	259	new_message.xdata = 0;
charly	0:b79cb3278583	260	new_message.crc = swapped;
charly	0:b79cb3278583	261
charly	0:b79cb3278583	262	//is the new message different from the old message?
charly	0:b79cb3278583	263	// or is another sender on air?
charly	0:b79cb3278583	264	if ((new_message.cnt != last_message.cnt) \|\| (new_message.adr != last_message.adr)) {
charly	0:b79cb3278583	265	last_message = new_message;
charly	0:b79cb3278583	266	message_received = true;
charly	0:b79cb3278583	267	}
charly	0:b79cb3278583	268
charly	0:b79cb3278583	269	} //crc_ok
charly	0:b79cb3278583	270	} //block_length = 9
charly	0:b79cb3278583	271	} //j==blocklength
charly	0:b79cb3278583	272	} //for
charly	0:b79cb3278583	273
charly	0:b79cb3278583	274
charly	0:b79cb3278583	275	//start receive from beginning
charly	0:b79cb3278583	276	buffer_cnt=0;
charly	0:b79cb3278583	277	bit_cnt=0;
charly	0:b79cb3278583	278	startbit=0;
charly	0:b79cb3278583	279	state=0;
charly	0:b79cb3278583	280	//pc.printf("\n\r-----------------------------\n\r");
charly	0:b79cb3278583	281	//clear the buffer
charly	0:b79cb3278583	282	for (i=0;i<1023;i++)buf[i]=0;
charly	0:b79cb3278583	283	*rxLED = 0; //turn off receive led
charly	0:b79cb3278583	284	} //buffer_cnt >8
charly	0:b79cb3278583	285	//////////////////////////////////////////////////////////////////////////////////////////////////////////
charly	0:b79cb3278583	286	//
charly	0:b79cb3278583	287	}
charly	0:b79cb3278583	288	}
charly	0:b79cb3278583	289
charly	0:b79cb3278583	290	}
charly	0:b79cb3278583	291
charly	0:b79cb3278583	292
charly	0:b79cb3278583	293
charly	0:b79cb3278583	294

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	27 Apr 2011
Imports:	15
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	3
Followers:	3

eth_comfort.cpp@0:b79cb3278583, 2011-04-27 (annotated)

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