GPS_SmartMode
Chuck Rice
Posts: 210
I am trying to use the GPS_SmartMode object. It works, but the Parallax GPS module is supposed to update about once a second. But to read all of the information, it ends up taking 10 to 12 seconds.
Is this a limit of the Object, or of the GPS module's smart mode. Do I have to go to RAW mode to get true 1Hz data? -Chuck-
Pub getGPSdata GPS.GetInfo(@hwString, @fwString) GPS.GetDateAndTime(@date_string, @time_string) valid := GPS.GetValid satellites:= GPS.GetSats latitude := GPS.GetLatitude longitude := GPS.GetLongitude altitude := GPS.GetAltitude speed := GPS.GetSpeed heading := GPS.GetHeading
Is this a limit of the Object, or of the GPS module's smart mode. Do I have to go to RAW mode to get true 1Hz data? -Chuck-
Comments
You should use the "dumb mode" which only listens.
Here is may latest version, there should be only minor changes needed for the Parallax module
Perry
Did you happen to try the posted code on the Parallax GPS module? Did it work straight away, or did you have to modify it at all?
Thanks,
Jason
The RAW-mode version works much faster. I have modified it a bit, but just to
add some comments and new calls. I am having trouble with the date though.
It always returns 0000000. Everything else seems to work. Here is a picture of it
running:
is running on one propboard, and sending the output to a second propboard
via a serial link for display. I am still in the middle of testing it, but here is the
code I use to call it:
GPS.start serial.tx(cCR) repeat loopStartCnt := cnt serial.tx(cClear) serial.str(string("FixQuality: ")) serial.str(GPS.FixQuality) serial.tx(cCR) serial.str(string(" altitude: ")) serial.str(GPS.altitude) serial.tx(cCR) serial.str(string(" speed: ")) serial.dec(GPS.speed) serial.tx(cCR) serial.str(string(" heading: ")) serial.dec(GPS.heading) serial.tx(cCR) serial.str(string(" time: ")) serial.str(GPS.time) serial.tx(cCR) serial.str(string(" date: ")) serial.hex(GPS.date,12) serial.tx(cCR) serial.str(string(" lat: ")) serial.str(GPS.latitude) serial.tx(" ") serial.str(GPS.N_S) serial.tx(cCR) serial.str(string(" long: ")) serial.str(GPS.longitude) serial.tx(" ") serial.str(GPS.E_W) serial.tx(cCR) if GPS.satelliteCount > 0 serial.str(string("sats: ")) serial.dec(GPS.satelliteCount) serial.tx(cCR) serial.str(string(" ids: ")) repeat i from 1 to GPS.satelliteCount serial.str(GPS.sat_id (i)) serial.tx(" ") serial.tx(" ") serial.tx(cCR) serial.str(string(" elev: ")) repeat i from 1 to GPS.satelliteCount serial.str(GPS.sat_elevation (i)) serial.tx(" ") serial.tx(" ") serial.tx(cCR) serial.str(string(" az:")) repeat i from 1 to GPS.satelliteCount serial.str(GPS.sat_azimuth (i)) serial.tx(" ") serial.tx(cCR) serial.str(string(" snr: ")) repeat i from 1 to GPS.satelliteCount serial.str(GPS.sat_snr (i)) serial.tx(" ") serial.tx(" ") serial.tx(cCR) waitcnt(Cnt+(clkfreq*1))Thanks to Perry for getting me started!
BTW Perry, what is RMC_Ready? It is always one, so I deleted it. -Chuck-
GPSready inicates that all 3 sat position rmc messages have been seen. used on an ovehead sat view (the mini version does not include this).
nearly every thing returned is a string in my code what is with date as "serial.hex(GPS.date,12)"
Perry
When I try displaying date as a string, I get a null string. To verify that it was a zero length string, I changed to display it as hex.
All three RMC messages? I thought that there was only 1 RMC sentence, but three GSV messages. I may be misunderstanding something.
I tried to attach my edited version of GPS_IO_full.spin, but I get an error trying to attach it. -Chuck-
My suspicion is that you should allocate 80 bytes for the rmc sentence.
The parallax module seems to output a little extra than the SIRF module I use.
It looks like there is still a bug in my code
Perry
I tried giving all sentences 90 bytes and I changed the two limit checks to 82, but no joy.
I think I need to dump the raw sentence. -Chuck-
statement was off by two for my GPS. I only get HHMMSS not HHMMSS.SS
The extra three characters (".SS") Were causing the test to be wrong.
also I added a cptr-- to remove the checksum "*" from the last field. The
star was showing up in the last field.
I also removed the code that tested for the doubled commas. You had
already replaced the comma with a null and that was sufficient to
terminate the null string.
I will post the modified code in the text since I get an error when I try
to attach it to this post.
'' ***************************** '' '' Raw mode GPS routines '' '' ***************************** CON CR = 13 ' ASCII <CR> LF = 10 ' ASCII <LF> serRecv = 8 ' Serial Receive VAR long gps_stack[noparse][[/noparse]22] byte GP_RMC_b [noparse][[/noparse]90], GP_GGA_b [noparse][[/noparse]90], GP_GSA_b [noparse][[/noparse]90] long GP_RMC_a [noparse][[/noparse]20], GP_GGA_a [noparse][[/noparse]20], GP_GSA_a [noparse][[/noparse]20] byte GP_GSV_1b [noparse][[/noparse]90], GP_GSV_2b[noparse][[/noparse]90], GP_GSV_3b[noparse][[/noparse]90] long GP_GSV_1a [noparse][[/noparse]20], GP_GSV_2a[noparse][[/noparse]20], GP_GSV_3a[noparse][[/noparse]20] byte gps_buff[noparse][[/noparse]90],Rx,chk_xsum,chk_xval long cog,cptr,ptr,arg,j long Null long rmc_ready OBJ uart : "HITT_Serial_Recv_Buffer_True_32" PUB start : okay '' Starts uart object (at baud specified) in a cog '' -- returns false if no cog available ' okay := uart.start(14,4800) ' (serRecv,serXmit,0,4800) okay := uart.Init (serRecv,4800) return cog := cognew(readNEMA,@gps_stack) + 1 pri readNEMA Null[noparse][[/noparse]0] := rmc_ready := 0 repeat longfill(gps_buff,20,0) repeat while Rx <> "$" ' wait for the $ to insure we are starting with Rx := uart.Rx ' a complete NMEA sentence cptr := 0 chk_xsum := 0 repeat while Rx <> "*" ' continue to collect data until the end of the NMEA sentence Rx := uart.Rx if Rx == "," gps_buff[noparse][[/noparse]cptr++] := 0 ' Replace the character else gps_buff[noparse][[/noparse]cptr++] := Rx ' Save the character if cptr > 82 quit if Rx <> "*" chk_xsum ^= Rx cptr-- chk_xval := to_hex(uart.Rx) << 4 chk_xval += to_hex(uart.Rx) if chk_xsum == chk_xval if gps_buff == "R" if gps_buff == "M" if gps_buff == "C" rmc_ready := 0 copy_buffer(@GP_RMC_b, @GP_RMC_a) if gps_buff == "G" if gps_buff == "G" if gps_buff == "A" copy_buffer(@GP_GGA_b, @GP_GGA_a) if gps_buff == "G" if gps_buff == "S" if gps_buff == "A" copy_buffer(@GP_GSA_b, @GP_GSA_a) if gps_buff == "G" if gps_buff == "S" if gps_buff == "V" if gps_buff[noparse][[/noparse]8] == "1" copy_buffer(@GP_GSV_1b, @GP_GSV_1a) if gps_buff[noparse][[/noparse]8] == "2" copy_buffer(@GP_GSV_2b, @GP_GSV_2a) if gps_buff[noparse][[/noparse]8] == "3" copy_buffer(@GP_GSV_3b, @GP_GSV_3a) rmc_ready := 1 pri copy_buffer ( buffer,args) bytemove(buffer,@gps_buff,cptr) ptr := buffer arg := 0 repeat j from 0 to 82 if arg > 19 quit if byte[noparse][[/noparse]ptr] == 0 long[noparse][[/noparse]args][noparse][[/noparse]arg++] := ptr+1 ptr++ pri to_hex(key) case key "0": return 0 "1": return 1 "2": return 2 "3": return 3 "4": return 4 "5": return 5 "6": return 6 "7": return 7 "8": return 8 "9": return 9 "A": return 10 "B": return 11 "C": return 12 "D": return 13 "E": return 14 "F": return 15 pri xsum return chk_xsum pri xval return chk_xval pub altitude '' Altitude, Meters, above mean sea level return GP_GGA_a[noparse][[/noparse]8] pub speed '' Speed over the ground in knots return GP_RMC_a[noparse][[/noparse]6] pub heading '' Track angle in degrees True return GP_RMC_a[noparse][[/noparse]7] pub time '' UTC time of fix HHMMSS return GP_GGA_a[noparse][[/noparse]0] pub date '' DDMMYY return GP_RMC_a[noparse][[/noparse]8] pub latitude '' degrees and minutes - dddmm.mmmm return GP_GGA_a pub N_S '' N = north or S = south return GP_GGA_a pub longitude '' degrees and minutes - dddmm.mmmm return GP_GGA_a pub E_W '' E = east or W = west return GP_GGA_a pub FixQuality {{ 0 = invalid 1 = GPS fix (SPS) 2 = DGPS fix 3 = PPS fix 4 = Real Time Kinematic 5 = Float RTK 6 = estimated (dead reckoning) (2.3 feature) 7 = Manual input mode 8 = Simulation mode }} return GP_GGA_a pub satellites '' Number of satellites being tracked (returns String) return GP_GGA_a[noparse][[/noparse]6] pub satelliteCount | n '' Number of satellites being tracked (returns a number) n := to_hex(byte[noparse][[/noparse]GP_GGA_a[noparse][[/noparse]6]][noparse][[/noparse]0]) *10 'uses existing hex lookup as a decimal lookup n += to_hex(byte[noparse][[/noparse]GP_GGA_a[noparse][[/noparse]6]]) return n pub hdop return GP_GGA_a[noparse][[/noparse]7] pub vdop return GP_GSA_a[noparse][[/noparse]14] pub ready return rmc_ready pub sat_id (sat) '' Ranges from 1 to 32 case sat 1: return GP_GSV_1a 2: return GP_GSV_1a[noparse][[/noparse]7] 3: return GP_GSV_1a[noparse][[/noparse]11] 4: return GP_GSV_1a[noparse][[/noparse]15] 5: return GP_GSV_2a 6: return GP_GSV_2a[noparse][[/noparse]7] 7: return GP_GSV_2a[noparse][[/noparse]11] 8: return GP_GSV_2a[noparse][[/noparse]15] 9: return GP_GSV_3a 10: return GP_GSV_3a[noparse][[/noparse]7] 11: return GP_GSV_3a[noparse][[/noparse]11] 12: return GP_GSV_3a[noparse][[/noparse]15] other: return 0 pub sat_elevation (sat) '' Ranges from 0 to 90 case sat 1: return GP_GSV_1a 2: return GP_GSV_1a[noparse][[/noparse]8] 3: return GP_GSV_1a[noparse][[/noparse]12] 4: return GP_GSV_1a[noparse][[/noparse]16] 5: return GP_GSV_2a 6: return GP_GSV_2a[noparse][[/noparse]8] 7: return GP_GSV_2a[noparse][[/noparse]12] 8: return GP_GSV_2a[noparse][[/noparse]16] 9: return GP_GSV_3a 10: return GP_GSV_3a[noparse][[/noparse]8] 11: return GP_GSV_3a[noparse][[/noparse]12] 12: return GP_GSV_3a[noparse][[/noparse]16] other: return 0 pub sat_azimuth (sat) '' True, Range 0 to 359 case sat 1: return GP_GSV_1a 2: return GP_GSV_1a[noparse][[/noparse]9] 3: return GP_GSV_1a[noparse][[/noparse]13] 4: return GP_GSV_1a[noparse][[/noparse]17] 5: return GP_GSV_2a 6: return GP_GSV_2a[noparse][[/noparse]9] 7: return GP_GSV_2a[noparse][[/noparse]13] 8: return GP_GSV_2a[noparse][[/noparse]17] 9: return GP_GSV_3a 10: return GP_GSV_3a[noparse][[/noparse]9] 11: return GP_GSV_3a[noparse][[/noparse]13] 12: return GP_GSV_3a[noparse][[/noparse]17] other: return 0 pub sat_snr (sat) '' Range 0 to 99, null when not tracking case sat 1: return GP_GSV_1a[noparse][[/noparse]6] 2: return GP_GSV_1a[noparse][[/noparse]10] 3: return GP_GSV_1a[noparse][[/noparse]14] 4: return GP_GSV_1a[noparse][[/noparse]18] 5: return GP_GSV_2a[noparse][[/noparse]6] 6: return GP_GSV_2a[noparse][[/noparse]10] 7: return GP_GSV_2a[noparse][[/noparse]14] 8: return GP_GSV_2a[noparse][[/noparse]18] 9: return GP_GSV_3a[noparse][[/noparse]6] 10: return GP_GSV_3a[noparse][[/noparse]10] 11: return GP_GSV_3a[noparse][[/noparse]14] 12: return GP_GSV_3a[noparse][[/noparse]18] other: return 0Thanks for giving me a good start. Your code saved me a lot of time
and it was interesting. You might want to post it in the object exchange.
-Chuck-
if it will help or hurt.
the longfill(gps_buff,0,20)
may need to be changed to longfill(gps_buff,20,0)
From the manual: LONGFILL(StartAddress, Value, Count )
it looks like the value and count are swapped. This causes the buffer
not to be zeroed, but I am not sure it needs to be as it seems to work
as is. -Chuck-
Even the code you quoted above shows the same.
This code, in mini version is in the object exchange obex.parallax.com/objects/225/
Perry
Yikes! I got it backwards too. The format is value,count.
"longfill(gps_buff,20,0)" says to put the value 20 into gps_buff zero times. Sorry for the confusion. -Chuck-
Perry