Line: 1 to 1 | ||||||||
---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | ||||||||
Line: 113 to 118 | ||||||||
What we will try to do is taking the data from the ublox neo 6M connected to the PC through the USB to serial connection instead of using the mobile phone. The strategy will be this: | ||||||||
Changed: | ||||||||
< < |
| |||||||
> > |
| |||||||
Following the tutorial step by step here is a screen dump of the result: | ||||||||
Added: | ||||||||
> > | Getting NMEA information for gpsd from the ESP32gpsd does not only allow reading GPS information from the serial line but it can also get this information from a TCP of UDP socket. It should therefore be possible to keep the ublox neo M6 connected to the ESP32 and write a simple TCP server (named ser2tcpServer.py. I use port 29998 for this server) which listens to a connection request from gpsd and then reads NMEA sentences from the ESP32 UART and transfers them to gpsd over the TCP socket. To get things to work we must:
Finally you pipe the messages from gpsd back into a socket with gpspipe -r | nc -l 29999 from where they are picked up by map.qml. The result will be the same map as shown above but the GPS source has been shifted from the PC serial port to the ESP32. | |||||||
-- Uli Raich - 2020-07-01 |
Line: 1 to 1 | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | |||||||||||
Line: 25 to 25 | |||||||||||
Here is a photo of the device: | |||||||||||
Added: | |||||||||||
> > | Reading NMEA sentences with the ESP32Once the connection is made and the UART instantiated all you need is an endless loop to read the UART line by line. This is what you will see if you print the result: These are sentences of the NMEA protocol. You will need a parser that extracts the relevant information from these messages. It is not too difficult to write such a parser yourself but why do you want to do it if the job has already be done for you? In fact Peter Hinch has a github repository with gps drivers containing all you need: https://github.com/peterhinch/micropython-async/tree/master/gps He uses the NMEA parser from https://github.com/inmcm/micropyGPS but adapted it to his asynchronous driver. | ||||||||||
Connecting the GPS receiver to your PCIn order to read out the GPS receiver from the PC we need a USB to serial converter: | |||||||||||
Line: 61 to 72 | |||||||||||
gpsd | |||||||||||
Changed: | |||||||||||
< < | The GPS daemon gpsd connects to a GPS receiver and provides its data to clients over a TCP connection.You can find it on https://gpsd.gitlab.io/gpsd/index.html
Reading NMEA sentences with the ESP32 | ||||||||||
> > | While u-center is a Windows application and can only be run on Linux through Windows emulation, there is also a GPS suite that runs natively on Linux named gpsd. | ||||||||||
Changed: | |||||||||||
< < | Once the connection is made and the UART instantiated all you need is an endless loop to read the UART line by line. This is what you will see if you print the result: | ||||||||||
> > | The GPS daemon gpsd connects to a GPS receiver and provides its data to clients over a TCP connection.You can find it on https://gpsd.gitlab.io/gpsd/index.html. | ||||||||||
Changed: | |||||||||||
< < | |||||||||||
> > | Check the gpsd documentation and in particular INSTALL.adoc and build.adoc in the source repository for information on how to build and install gpsd. | ||||||||||
Changed: | |||||||||||
< < | These are sentences of the NMEA protocol. You will need a parser that extracts the relevant information from these messages. It is not too difficult to write such a parser yourself but why do you want to do it if the job has already be done for you? In fact Peter Hinch has a github repository with gps drivers containing all you need: | ||||||||||
> > | Once installed we first make sure that the daemon is not already running:
systemctl stop gpsd systemctl stop gpsd.socket | ||||||||||
Changed: | |||||||||||
< < | https://github.com/peterhinch/micropython-async/tree/master/gps | ||||||||||
> > | To check that the GPS receiver is sending data we can check with gpscat: gpscat -s 115200 /dev/ttyUSB0 | ||||||||||
Changed: | |||||||||||
< < | He uses the NMEA parser from https://github.com/inmcm/micropyGPS but adapted it to his asynchronous driver. | ||||||||||
> > |
Then we can run gpsd as a foreground process (-N), specify the baud rate (-s 115200) and the serial port to which the neo 6M is connected (/dev/ttyUSB0): gpsd -N -s 115200 /dev/ttyUSB0 Once the daemon is running we use gpspipe to see the NMEA sentences on the console: gpspipe -r This time the the NMEA sentences are not picked up from the USB to serial converted but from the TCP/IP port 2947 where gpsd provides information to its clients. Now that we know that gpsd is working normally we can start gspmon which extracts basic GPS information like latitude, longitude, altitude and time and some information about the satellites seen. Finally we run xgps to give us a graphical representation of the satellites in the sky. More programs are part of gpsd but I will let you discover those yourself. Showing GPS position information on a mapThere is a nice tutorial from the Linux journal describing how to use gpsd when taking GPS information from a mobile phone:
| ||||||||||
-- Uli Raich - 2020-07-01 | |||||||||||
Line: 86 to 133 | |||||||||||
| |||||||||||
Added: | |||||||||||
> > |
|
Line: 1 to 1 | ||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | ||||||||||||||||||||||
Line: 26 to 25 | ||||||||||||||||||||||
Here is a photo of the device: | ||||||||||||||||||||||
Added: | ||||||||||||||||||||||
> > | Connecting the GPS receiver to your PCIn order to read out the GPS receiver from the PC we need a USB to serial converter: As can be seen on the photo the connections must be made as follows (pin 1 is the leftmost pin)
ublox u-centerublox provides a Windows application for its GPS receivers named u-center which you can download from https://www.u-blox.com/en/product/u-center. Its user guide can be found at https://www.u-blox.com/sites/default/files/u-center_Userguide_%28UBX-13005250%29.pdf. It is possible to run this application on Linux using the Windows emulator wine. u-center allows you to connect to a Windows com port in order to communicate with the receiver. When running the u-center installation you will get the executable in~/.wine/drive_c/Program Files (x86)/u-blox/u-center_v20.06.01 Finally we must figure out to which Windows com port our USB to serial adapter corresponds to. Looking at ~/.wine/dosdevices shows that /dev/ttyUSB0 is mapped to com33. ublox GPS receivers use 2 different protocols
gpsdThe GPS daemon gpsd connects to a GPS receiver and provides its data to clients over a TCP connection.You can find it on https://gpsd.gitlab.io/gpsd/index.htmlReading NMEA sentences with the ESP32 | |||||||||||||||||||||
Once the connection is made and the UART instantiated all you need is an endless loop to read the UART line by line. This is what you will see if you print the result: | ||||||||||||||||||||||
Line: 45 to 82 | ||||||||||||||||||||||
| ||||||||||||||||||||||
Added: | ||||||||||||||||||||||
> > |
|
Line: 1 to 1 | ||||||||
---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | ||||||||
Line: 18 to 19 | ||||||||
| ||||||||
Changed: | ||||||||
< < |
| |||||||
> > |
| |||||||
|
Line: 1 to 1 | ||||||||
---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | ||||||||
Line: 8 to 8 | ||||||||
| ||||||||
Deleted: | ||||||||
< < | ||||||||
uart2=machine.UART(2, baudrate=9600, rx=21, tx=22, timeout=10000) | ||||||||
Added: | ||||||||
> > | For more information about the ESP32 UART driver in MicroPython see https://docs.micropython.org/en/latest/library/machine.UART.html#machine-uart | |||||||
The card on which the Neo 6M GPS receiver is mounted has 4 connection pins (starting from the left):
|
Line: 1 to 1 | |||||||||
---|---|---|---|---|---|---|---|---|---|
The Neo 6M GPS receiver | |||||||||
Added: | |||||||||
> > | Most GPS receivers use a UART to communicate with their hosts and the Neo 6M is no exception. The ESP32 has 3 hardware UARTs with the following default connections:
| ||||||||
The card on which the Neo 6M GPS receiver is mounted has 4 connection pins (starting from the left):
| |||||||||
Changed: | |||||||||
< < |
| ||||||||
> > |
| ||||||||
| |||||||||
Changed: | |||||||||
< < | As you can see from the pin names, the GPS receiver is controlled/read out through a UART. Default baud rate is 9600 baud. The pins on the ESP32 correspond to UART2 of the ESP32 chip. | ||||||||
> > | Only Pin D2 or GPIO 21 is actually used and as you can tell from the instantiation of UART2 shown above the Neo 6M receiver communicates on 9600 baud. | ||||||||
Here is a photo of the device: | |||||||||
Added: | |||||||||
> > | Once the connection is made and the UART instantiated all you need is an endless loop to read the UART line by line. This is what you will see if you print the result: These are sentences of the NMEA protocol. You will need a parser that extracts the relevant information from these messages. It is not too difficult to write such a parser yourself but why do you want to do it if the job has already be done for you? In fact Peter Hinch has a github repository with gps drivers containing all you need: https://github.com/peterhinch/micropython-async/tree/master/gps He uses the NMEA parser from https://github.com/inmcm/micropyGPS but adapted it to his asynchronous driver. | ||||||||
-- Uli Raich - 2020-07-01
Comments | |||||||||
Line: 22 to 40 | |||||||||
| |||||||||
Added: | |||||||||
> > |
|
Line: 1 to 1 | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Added: | |||||||||||||||
> > |
The Neo 6M GPS receiverThe card on which the Neo 6M GPS receiver is mounted has 4 connection pins (starting from the left):
Comments
|