3 // ** Acurite 5n1 functions **
5 const float acurite_winddirections[] =
6 { 337.5, 315.0, 292.5, 270.0, 247.5, 225.0, 202.5, 180,
7 157.5, 135.0, 112.5, 90.0, 67.5, 45.0, 22.5, 0.0 };
9 static int acurite_raincounter = 0;
11 static int acurite_crc(uint8_t row[BITBUF_COLS], int cols) {
12 // sum of first n-1 bytes modulo 256 should equal nth byte
15 for ( i=0; i < cols; i++)
17 if ( sum % 256 == row[cols] )
23 static int acurite_detect(uint8_t *pRow) {
25 if ( pRow[0] != 0x00 ) {
26 // invert bits due to wierd issue
27 for (i = 0; i < 8; i++)
28 pRow[i] = ~pRow[i] & 0xFF;
29 pRow[0] |= pRow[8]; // fix first byte that has mashed leading bit
31 if (acurite_crc(pRow, 7))
32 return 1; // passes crc check
37 static float acurite_getTemp (uint8_t highbyte, uint8_t lowbyte) {
39 int highbits = (highbyte & 0x0F) << 7 ;
40 int lowbits = lowbyte & 0x7F;
41 int rawtemp = highbits | lowbits;
42 float temp = (rawtemp - 400) / 10.0;
46 static int acurite_getWindSpeed (uint8_t highbyte, uint8_t lowbyte) {
47 // range: 0 to 159 kph
48 // TODO: sensor does not seem to be in kph, e.g.,
49 // a value of 49 here was registered as 41 kph on base unit
50 // value could be rpm, etc which may need (polynomial) scaling factor??
51 int highbits = ( highbyte & 0x1F) << 3;
52 int lowbits = ( lowbyte & 0x70 ) >> 4;
53 int speed = highbits | lowbits;
57 static float acurite_getWindDirection (uint8_t byte) {
58 // 16 compass points, ccw from (NNW) to 15 (N)
59 int direction = byte & 0x0F;
60 return acurite_winddirections[direction];
63 static int acurite_getHumidity (uint8_t byte) {
65 int humidity = byte & 0x7F;
69 static int acurite_getRainfallCounter (uint8_t hibyte, uint8_t lobyte) {
70 // range: 0 to 99.99 in, 0.01 in incr., rolling counter?
71 int raincounter = ((hibyte & 0x7f) << 7) | (lobyte & 0x7F);
75 static int acurite5n1_callback(uint8_t bb[BITBUF_ROWS][BITBUF_COLS],int16_t bits_per_row[BITBUF_ROWS]) {
76 // acurite 5n1 weather sensor decoding for rtl_433
80 // run through rows til we find one with good crc (brute force)
81 for (i=0; i < BITBUF_ROWS; i++) {
82 if (acurite_detect(bb[i])) {
90 fprintf(stdout, "SENSOR:TYPE=ACURITE_5IN1,");
93 fprintf(stderr, "%02X ", buf[i]);
94 fprintf(stderr, "CRC OK\n");
97 if ((buf[2] & 0x0F) == 1) {
98 // wind speed, wind direction, rainfall
100 float rainfall = 0.00;
101 int raincounter = acurite_getRainfallCounter(buf[5], buf[6]);
102 if (acurite_raincounter > 0) {
103 // track rainfall difference after first run
104 rainfall = ( raincounter - acurite_raincounter ) * 0.01;
106 // capture starting counter
107 acurite_raincounter = raincounter;
110 fprintf(stdout, "WINDSPEED=%d,",
111 acurite_getWindSpeed(buf[3], buf[4]));
112 fprintf(stdout, "WINDDIRECTION=%0.1f,",
113 acurite_getWindDirection(buf[4]));
114 fprintf(stdout, "RAINGAUGE=%0.2f\n", rainfall);
116 } else if ((buf[2] & 0x0F) == 8) {
117 // wind speed, temp, RH
118 fprintf(stdout, "WINDSPEED=%d,",
119 acurite_getWindSpeed(buf[3], buf[4]));
120 fprintf(stdout, "TEMP=%2.1f,",
121 acurite_getTemp(buf[4], buf[5]));
122 fprintf(stdout, "HUMIDITY=%d\n",
123 acurite_getHumidity(buf[6]));
130 debug_callback(bb, bits_per_row);
135 static int acurite_rain_gauge_callback(uint8_t bb[BITBUF_ROWS][BITBUF_COLS], int16_t bits_per_row[BITBUF_ROWS]) {
136 // This needs more validation to positively identify correct sensor type, but it basically works if message is really from acurite raingauge and it doesn't have any errors
137 if ((bb[0][0] != 0) && (bb[0][1] != 0) && (bb[0][2]!=0) && (bb[0][3] == 0) && (bb[0][4] == 0)) {
138 float total_rain = ((bb[0][1]&0xf)<<8)+ bb[0][2];
139 total_rain /= 2; // Sensor reports number of bucket tips. Each bucket tip is .5mm
140 fprintf(stdout, "SENSOR:TYPE=ACURITE_RAIN_GAUGE,RAIN=%2.1f\n", total_rain);
141 fprintf(stderr, "Raw Message: %02x %02x %02x %02x %02x\n",bb[0][0],bb[0][1],bb[0][2],bb[0][3],bb[0][4]);
147 static int acurite_th_detect(uint8_t *buf){
148 if(buf[5] != 0) return 0;
149 uint8_t sum = (buf[0] + buf[1] + buf[2] + buf[3]) & 0xff;
150 if(sum == 0) return 0;
151 return sum == buf[4];
153 static float acurite_th_temperature(uint8_t *s){
154 uint16_t shifted = (((s[1] & 0x0f) << 8) | s[2]) << 4; // Logical left shift
155 return (((int16_t)shifted) >> 4) / 10.0; // Arithmetic right shift
157 static int acurite_th_callback(uint8_t bb[BITBUF_ROWS][BITBUF_COLS], int16_t bits_per_row[BITBUF_ROWS]) {
160 for(i = 0; i < BITBUF_ROWS; i++){
161 if(acurite_th_detect(bb[i])){
167 fprintf(stdout, "SENSOR:TYPE=ACURITE_TEMP,");
168 fprintf(stdout, "TEMP=%.1f,", acurite_th_temperature(buf));
169 fprintf(stderr, "HUMIDITY=%d\n", buf[3]);
176 r_device acurite5n1 = {
178 /* .name = */ "Acurite 5n1 Weather Station",
179 /* .modulation = */ OOK_PWM_P,
180 /* .short_limit = */ 70,
181 /* .long_limit = */ 240,
182 /* .reset_limit = */ 21000,
183 /* .json_callback = */ &acurite5n1_callback,
186 r_device acurite_rain_gauge = {
188 /* .name = */ "Acurite 896 Rain Gauge",
189 /* .modulation = */ OOK_PWM_D,
190 /* .short_limit = */ 1744/4,
191 /* .long_limit = */ 3500/4,
192 /* .reset_limit = */ 5000/4,
193 /* .json_callback = */ &acurite_rain_gauge_callback,
196 r_device acurite_th = {
198 /* .name = */ "Acurite Temperature and Humidity Sensor",
199 /* .modulation = */ OOK_PWM_D,
200 /* .short_limit = */ 300,
201 /* .long_limit = */ 550,
202 /* .reset_limit = */ 2500,
203 /* .json_callback = */ &acurite_th_callback,