Rpi3, grovepi+ and Grove GPS sensor

cleoqc · June 20, 2016, 11:22am

Sorry, I was away from a Pi3 for the last day.

If I try stty -a, I get


speed 38400 baud; rows 24; columns 80; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = &lt;undef&gt;;
eol2 = &lt;undef&gt;; swtch = &lt;undef&gt;; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff
-iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke

I also have the following in my /boot/config.txt file:


dtparam=spi=on
init_uart_clock=32000000
dtparam=i2c1=on
dtparam=i2c_arm=on
dtoverlay=pi3-miniuart-bt

My Pi3 works with the GPS. although it takes a while to warm up. It seems to take longer than the Pi2 to find satellites and get data from them

JohnC · June 21, 2016, 11:37am

“With the same setup (indeed same SD card) on a Rpi2 I get NMEA valid lines, but still no actual coordinates.”

Do you have a screenshot of this? It sounds like your sensor might be bad, you might need to ask Seeed for a replacement.

zilog · June 21, 2016, 2:49pm

Thanks John! I attach a full log to this post. It never seems to get more than three satellites and it never gives a reading after leaving it running for a good 30 minutes outdoor in the balcony, clear view of (cloudy) sky. I get a very tight gps reading on my phone.

This is after I remade the Rpi2 image by following step by step the instructions in your site, and updating, it went a bit more smoothly this time. But still no usable readings. Could this be a faulty unit? Can you see anything unfamiliar in the log?

cleoqc · June 21, 2016, 4:54pm

I now have my GPS on a Pi3, and now I’m getting similar results as you.
This was working yesterday, on the same setup. I haven’t changed anything except the camera. (camera cable died)
I’ll look into it later tonight, right now the dog needs a walk

cleoqc · June 21, 2016, 6:08pm

Sorry about that. The dog was being a pest.
It dawned on me that, yes, I changed something and that is the power! If I run it from a battery that is not fully charged then my Gpgga lines are empty. A good power supply fixed my issue.

What is your power source? I don’t know yet if it’s a coincidence for me or not.

zilog · June 22, 2016, 12:45am

Hi Cleo,

Thanks a lot for your input. My setup is powered from an official Rpi wallwart delivering up to 2Amps. I have tried with Rpi + touchscreen and without touchscreen (precisely thinking that maybe power could be an issue), and nothing I tried could make the sensor work.

Attached to this post is a picture of my setup, there are two sensors in the picture, GPS and IMU, the IMU is not connected during tests.

zilog · June 22, 2016, 12:49am

Today I woke up early and I tried something else. I got an Arduino Nano that I had laying around and tried to connect it directly to the GPS sensors without the Grove shield. This is the wiring I used:

`GPS ARD`

VCC -> 5V
GND -> GND
RX -> D2
TX -> D3

And then I tried this code: http://www.seeedstudio.com/wiki/Grove_-_GPS#With_Arduino

Nothing. No output whatsoever.

At this point I am about to give up, I’m running out of time and I can’t seem to get it to work. If you have any suggestions I’m all ears.

JohnC · June 23, 2016, 11:55am

Hi Zilog, it looks like your GPS and your GrovePi are communicating just fine. You can see the time is even incrementing in this output.

[’$GPGGA’, ‘000217.799’, ‘’, ‘’, ‘’, ‘’, ‘0’, ‘0’, ‘’, ‘’, ‘M’, ‘’, ‘M’, ‘’, ‘*4B\r\n’]
Time : 000217.799
Fix status : 0
Sats in view : 0
Altitude : -1.000000
Lat : -1.000000
Long : -1.000000

[’$GPGGA’, ‘000218.799’, ‘’, ‘’, ‘’, ‘’, ‘0’, ‘0’, ‘’, ‘’, ‘M’, ‘’, ‘M’, ‘’, ‘*44\r\n’]
Time : 000218.799
Fix status : 0
Sats in view : 0
Altitude : -1.000000
Lat : -1.000000
Long : -1.000000

For some reason, your GPS sensor isn’t putting out valid data (obviously you’re not at -1 altitude). So one of two tings could be going on. First, you might need to just get a valid GPS fix. I’m not sure if this sensor puts that out when it doesn’t have a fix.

You may also have a non-working GPS sensor.

You may want to ask Seeed to exchange this sensor with another one, the GrovePi and the software are working fine, this is a problem with the sensor.

zilog · June 25, 2016, 4:56am

In the end I sent the sensor back to the distributor because I wasn’t happy with it. I got another one today and this one works right out of the box.

Thanks a lot for your kind advice everyone! This forum is wonderfully supportive, thanks!

JohnC · June 27, 2016, 3:36am

Zilog, so glad to hear you’re on your way!! let us know how it works out!

frozentrace · September 21, 2016, 2:42pm

Hi there,

was anyone able to get the grove gps sensor working with raspberry pi 3 and grovepi+?

thanks in advance.

JohnC · September 25, 2016, 1:33pm

Yes, it looks like the original author @zilog was able to get it to work by replacing a defective GPS sensor. Are you having trouble as well?

Shoban · September 26, 2016, 5:21am

Hi @frozentrace,

Can you tell us what all you have tried and also if you have tried the steps mentioned in this post.
Can you also tell us what image you are using on the Pi.

-Shoban

jwclark · March 23, 2017, 2:59pm

I’m on a RaspberryPi 3, running the Pixel image which is Debian Jessie. I have a classroom full of students trying to get the GPS sensor working on GrovePi boards. None of them work. I doubt they’re all defective sensors. We are all plugged into the RPISER serial port using the dextergps.py file. Windows are nearby and still no data. What could be the problem?

Shoban · March 24, 2017, 5:15am

Hi @jwclark,

In the Debian Jessie image the UART is disabled by default. Can you try our Raspbian for Robots Image, it will be a lot more easier to connect to and use in classrooms, GPS should work with it. You can follow the instructions here to install Raspbian for Robots. Learn more about our image here.

-Shoban

jwclark · March 24, 2017, 5:30am

@Shoban I opened a new question on this topic. I already installed that image - no luck. This is the link from your website: https://drive.google.com/file/d/0B0WChwP4CnLBU1hLRjBQZndTYU0/view and it points to a Jessie build. Should I be using a different image?

JohnC · March 28, 2017, 10:50am

@jwclark, that’s right. As @Shoban points out, the issue is probably the UART not being enabled. You can run Raspbian for Robots (links above) or you can enable UART by running sudo raspi-config and selecting advanced options, from there enabling UART.

Also, it’s worth noting: windows nearby may not be enough skyline to see GPS satellites. You may need to take the boards either right up against a window or outside to pickup GPS sats.

anushreemath1995 · October 23, 2017, 9:16am

@JohnC
I am using RPI3 (RASPBIAN STRETCH WITH DESKTOP) and grovepi+ and gps sensor. I am not getting any output.
I tried GrovePi/Software/Python/grove_GPS/grove_gps_hardware_test.py no output at all. Could you please tell where I am going wrong? (I disabled bluetooth thinking that it may be using URAT(serial1))

I am using code from http://wiki.seeed.cc/Grove-GPS/

anushreemath1995 · October 24, 2017, 4:50am

I got the output. I used ttyS0 instead of AMA0.

JohnC · November 4, 2017, 11:12am