1 | #!/bin/sh |
---|
2 | # |
---|
3 | # see http://aprs.gids.nl/nmea |
---|
4 | |
---|
5 | # DEV=${1:-/dev/ttymxc0} |
---|
6 | DEV=${1:-/dev/ttymxc4} |
---|
7 | BAUD=${2:-4800} #might need to go to 9600? |
---|
8 | |
---|
9 | [ $VERBOSE ] || VERBOSE=0 |
---|
10 | |
---|
11 | #Estimated Moving Avgerage: EMA = EMA * (1 – APLHA) + NEWAVG * ALPHA |
---|
12 | #Variables for calculating moving averages: |
---|
13 | #SRN_EMA: EMA for sattellite signal strength |
---|
14 | #SAT_EMA: EMA for number of visible sattellites |
---|
15 | SRN_AVG=0 #srn_sum / srn_cnt |
---|
16 | ALPHA=$(echo ${3:-10} | awk '{alph = 1/$1; print alph}') #default of last 10 |
---|
17 | |
---|
18 | echo "Device:$DEV" |
---|
19 | echo "Baud :$BAUD" |
---|
20 | |
---|
21 | stty -F $DEV $BAUD cs8 |
---|
22 | |
---|
23 | debug() { |
---|
24 | [ $VERBOSE -ge $1 ] && echo $2 |
---|
25 | } |
---|
26 | |
---|
27 | # GPS DOP and active satellites |
---|
28 | gsa() { |
---|
29 | local i x sats type fix pdop hdop vdop |
---|
30 | |
---|
31 | #debug 1 "gsa: $1" |
---|
32 | oIFS=${IFS} |
---|
33 | IFS=',' |
---|
34 | i=0 |
---|
35 | sats= |
---|
36 | for x in $1; do |
---|
37 | case $i in |
---|
38 | 1) type=$x;; |
---|
39 | 2) fix=$x;; |
---|
40 | 3) sats="$sats$x ";; |
---|
41 | 4) sats="$sats$x ";; |
---|
42 | 5) sats="$sats$x ";; |
---|
43 | 6) sats="$sats$x ";; |
---|
44 | 7) sats="$sats$x ";; |
---|
45 | 8) sats="$sats$x ";; |
---|
46 | 9) sats="$sats$x ";; |
---|
47 | 10) sats="$sats$x ";; |
---|
48 | 11) sats="$sats$x ";; |
---|
49 | 12) sats="$sats$x ";; |
---|
50 | 13) sats="$sats$x ";; |
---|
51 | 14) sats="$sats$x ";; |
---|
52 | 15) pdop=$x;; |
---|
53 | 16) hdop=$x;; |
---|
54 | 17) vdop=$x;; |
---|
55 | esac |
---|
56 | i=$((i+1)) |
---|
57 | done |
---|
58 | |
---|
59 | case $type in |
---|
60 | M) type=manual;; |
---|
61 | A) type=automatic;; |
---|
62 | esac |
---|
63 | case $fix in |
---|
64 | 2) fix=2;; #2D |
---|
65 | 3) fix=3;; #3D |
---|
66 | esac |
---|
67 | |
---|
68 | [ ${fix} -ne 1 ] && echo "GSA: $fix $type $sats" |
---|
69 | IFS=${oIFS} |
---|
70 | } |
---|
71 | |
---|
72 | # Fix data |
---|
73 | gga() { |
---|
74 | local i x time lat lon type svs prec alt altm |
---|
75 | |
---|
76 | #debug 1 "gga: $1" |
---|
77 | oIFS=${IFS} |
---|
78 | IFS=',' |
---|
79 | i=0 |
---|
80 | for x in $1; do |
---|
81 | case $i in |
---|
82 | 1) time=$x;; |
---|
83 | 2) lat=$x;; |
---|
84 | 3) lat=$lat$x;; |
---|
85 | 4) lon=$x;; |
---|
86 | 5) lon=$lon$x;; |
---|
87 | 6) type=$x;; |
---|
88 | 7) svs=$x;; |
---|
89 | 8) prec=$x;; |
---|
90 | 9) alt=$x;; |
---|
91 | esac |
---|
92 | i=$((i+1)) |
---|
93 | done |
---|
94 | |
---|
95 | case $type in |
---|
96 | 1) type=1;; #GPS |
---|
97 | 2) type=2;; #DGPS |
---|
98 | esac |
---|
99 | |
---|
100 | [ ${type} -ne 0 ] && echo "$qual Fix: $time: $svs $lat/$lon/$alt" |
---|
101 | IFS=${oIFS} |
---|
102 | } |
---|
103 | |
---|
104 | gsv() { |
---|
105 | local i x s msgtot msgnum inview crc line |
---|
106 | local prn1 elev1 az1 snr1 |
---|
107 | local prn2 elev2 az2 snr2 |
---|
108 | local prn3 elev3 az3 snr3 |
---|
109 | local prn4 elev4 az4 snr4 |
---|
110 | |
---|
111 | line=${1%%\**} |
---|
112 | oIFS=${IFS} |
---|
113 | IFS=',' |
---|
114 | i=0 |
---|
115 | for x in $line; do |
---|
116 | case $i in |
---|
117 | 1) msgtot=$x;; |
---|
118 | 2) msgnum=$x |
---|
119 | [ $msgnum -eq 1 ] && { |
---|
120 | echo "GPS DATA BEGINS:" |
---|
121 | srn_cnt=0 |
---|
122 | srn_sum=0 |
---|
123 | sat_cnt=0 |
---|
124 | } |
---|
125 | ;; |
---|
126 | 3) inview=$x;; |
---|
127 | 4) prn1=$x;; |
---|
128 | 5) elev1=$x;; |
---|
129 | 6) sz1=$x;; |
---|
130 | 7) snr1=$x;; |
---|
131 | 8) prn2=$x;; |
---|
132 | 9) elev2=$x;; |
---|
133 | 10) sz2=$x;; |
---|
134 | 11) snr2=$x;; |
---|
135 | 12) prn3=$x;; |
---|
136 | 13) elev3=$x;; |
---|
137 | 14) sz3=$x;; |
---|
138 | 15) snr3=$x;; |
---|
139 | 16) prn4=$x;; |
---|
140 | 17) elev4=$x;; |
---|
141 | 18) sz4=$x;; |
---|
142 | 19) snr4=${x%%\**}; crc=${x##*\*};; |
---|
143 | esac |
---|
144 | case $i in |
---|
145 | 7|11|15|19) |
---|
146 | [ $i -eq 19 ] && x=$snr4 |
---|
147 | #echo "i is $i, X is $x" |
---|
148 | [ "$x" ] && [ $x -gt 0 ] && { |
---|
149 | srn_cnt=$(( srn_cnt + 1 )) |
---|
150 | srn_sum=$(( srn_sum + x )) |
---|
151 | };; |
---|
152 | esac |
---|
153 | i=$((i+1)) |
---|
154 | done |
---|
155 | |
---|
156 | |
---|
157 | s=$(( ((msgnum-1)) *4)) |
---|
158 | echo "Message $msgnum of $msgtot" |
---|
159 | debug 1 "gsv: $1" |
---|
160 | [ "$snr1" -o "$snr2" -o "$snr3" -o "$snr4" ] || echo "-- No Satellites --" |
---|
161 | # [ "$snr1" -o "$snr2" -o "$snr3" -o "$snr4" ] && echo "----BEGIN GPS DATA----" |
---|
162 | [ "$snr1" ] && printf "%02d:%s:%s:%s:%s\n" $((s+1)) $prn1 $elev1 $sz1 $snr1 && sat_cnt=$((sat_cnt+1)) |
---|
163 | [ "$snr2" ] && printf "%02d:%s:%s:%s:%s\n" $((s+2)) $prn2 $elev2 $sz2 $snr2 && sat_cnt=$((sat_cnt+1)) |
---|
164 | [ "$snr3" ] && printf "%02d:%s:%s:%s:%s\n" $((s+3)) $prn3 $elev3 $sz3 $snr3 && sat_cnt=$((sat_cnt+1)) |
---|
165 | [ "$snr4" ] && printf "%02d:%s:%s:%s:%s\n" $((s+4)) $prn4 $elev4 $sz4 $snr4 && sat_cnt=$((sat_cnt+1)) |
---|
166 | # [ "$snr1" -o "$snr2" -o "$snr3" -o "$snr4" ] && echo "-----END GPS DATA-----" |
---|
167 | |
---|
168 | [ $msgnum -eq $msgtot ] && { |
---|
169 | # echo "srn_cnt is $srn_cnt" |
---|
170 | [ "$srn_cnt" -eq 0 ] && SRN_AVG=0 |
---|
171 | [ "$srn_cnt" -ne 0 ] && SRN_AVG=$(echo "$srn_sum $srn_cnt" | awk '{avg = $1/$2; print avg}') |
---|
172 | [ "$SRN_EMA" ] || SRN_EMA=$SRN_AVG |
---|
173 | SRN_EMA=$(echo "$SRN_AVG $SRN_EMA $ALPHA" | awk '{EMA = $2 * (1 - $3) + $1 * $3; print EMA}') |
---|
174 | [ "$SAT_EMA" ] || SAT_EMA=$srn_cnt |
---|
175 | SAT_EMA=$(echo "$srn_cnt $SAT_EMA $ALPHA" | awk '{EMA = $2 * (1 - $3) + $1 * $3; print EMA}') |
---|
176 | printf "SRN average: %s, Visible Satellite Average: %s,\ |
---|
177 | Current Satellites in view: %s\n\n" $SRN_EMA $SAT_EMA $sat_cnt |
---|
178 | } |
---|
179 | |
---|
180 | IFS=${oIFS} |
---|
181 | } |
---|
182 | |
---|
183 | oIFS=${IFS} |
---|
184 | |
---|
185 | while [ 1 ]; do |
---|
186 | IFS='' read -r line |
---|
187 | debug 2 "${#line}: $line" |
---|
188 | |
---|
189 | # use case statement for easy regex |
---|
190 | case "$line" in |
---|
191 | *GSV,*) gsv "$line";; |
---|
192 | *GSA,*) gsa "$line";; |
---|
193 | *GGA,*) gga "$line";; |
---|
194 | esac |
---|
195 | done < $DEV |
---|
196 | |
---|
197 | IFS=$oIFS |
---|
198 | |
---|
199 | ########### END ############## |
---|
200 | |
---|
201 | |
---|
202 | ### from OSP to NMEA script |
---|
203 | # #!/bin/sh |
---|
204 | |
---|
205 | # # Make sure we talk to the device at its current configured data format |
---|
206 | # # (assuming power-on default of 4800 8N1) |
---|
207 | # stty -F /dev/gpsdevice 4800 cs8 |
---|
208 | |
---|
209 | # # change to mode=0 (OSP/SiRF binary) 9600bd 8N1 |
---|
210 | # echo "\$PSRF100,0,9600,8,1,0*0C" > /dev/gpsdevice |
---|
211 | # echo "\$PSRF100,1,9600,8,1,0*0D" > /dev/gpsdevice |
---|
212 | |
---|
213 | # # set new tty baudrate for future communication |
---|
214 | # stty -F /dev/gpsdevice 9600 |
---|
215 | |
---|
216 | ## changing baud rate of NMEA |
---|
217 | #stty -F /dev/ttymxc4 4800 cs8 |
---|
218 | #echo "\$PSRF100,1,9600,8,1,0*0D" > /dev/ttymxc4 |
---|
219 | #stty -F /dev/ttymxc4 9600 |
---|