Gps is not recognized by the system
« on: May 23, 2017, 03:11:06 pm »
Good morning everyone, I bought a gps ublox 7M and when connecting in the revolution the same is flashing the led but is not recognized by the system, gets the error as gps not connected with a red "X". I checked all the connections and everything is ok , I opened the gps and found the wires in the following connection: pin 1 GND, pin 2 Vcc, pin 3 Tx, pin 4 Rx. Would I have to invert pins 3 and 4 to connect the Gps Tx to the FlexiPort Rx? Or is the Gps damaged?

utoedter

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Re: Gps is not recognized by the system
« Reply #1 on: May 23, 2017, 04:01:19 pm »
Good morning everyone, I bought a gps ublox 7M and when connecting in the revolution the same is flashing the led but is not recognized by the system, gets the error as gps not connected with a red "X". I checked all the connections and everything is ok , I opened the gps and found the wires in the following connection: pin 1 GND, pin 2 Vcc, pin 3 Tx, pin 4 Rx. Would I have to invert pins 3 and 4 to connect the Gps Tx to the FlexiPort Rx? Or is the Gps damaged?

Swapping RX and TX shall not destroy the revolution, but i would use a cheap FTDI Device, connect the GPS to that one, download the ublox software and test it.  Maybe you have to built a little adapter for wiring (Micro JST-4 socket). That software is very talkative.

Udo

Re: Gps is not recognized by the system
« Reply #2 on: May 23, 2017, 04:21:02 pm »
utoedter , Can you tell me how to connect gps to ftdi?

utoedter

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Re: Gps is not recognized by the system
« Reply #3 on: May 23, 2017, 07:48:38 pm »
utoedter , Can you tell me how to connect gps to ftdi?

yes thats easy. If you need to buy a FTDI Adapter, choose one, which allows you to select the voltage, ive used 5V for the GPS. After installing the right driver, you got a virtual COM: port as serial interface. The pins on the FTDI are labeled, so it shall be easy to plug all together. The adapater cable is self made from a micro JST-4 pigtail.

« Last Edit: May 23, 2017, 07:52:35 pm by utoedter »

f5soh

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Re: Gps is not recognized by the system
« Reply #4 on: May 23, 2017, 08:18:46 pm »
Quote
Would I have to invert pins 3 and 4 to connect the Gps Tx to the FlexiPort Rx?

That the usual way for FC < > GPS connexion.
Tx (GPS) to Rx (pin4) MainPort or Flexiport
https://librepilot.atlassian.net/wiki/display/LPDOC/Revolution+Configuration#RevolutionConfiguration-MainPort

Revo board can replace the FTDI and no need to make adapters or soldering.
Just choose "ComBridge" for USB port and the port where the GPS is connected. (Reboot the board to apply changes)

At end, if the connection is fine there is no need to use the UBXCenter software because the GPS is configured at power-up by the Revo.

Re: Gps is not recognized by the system
« Reply #5 on: May 23, 2017, 08:38:33 pm »
f5soh, So I need to invert pin 4 with pin 3 on the Gps, to get the tx of the connected Gps in the Flexiport rx.

Mateusz

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Re: Gps is not recognized by the system
« Reply #6 on: May 23, 2017, 08:56:05 pm »
Master Satan says:

Serial connection is always TX (transmitting) to RX (receiving). Each side has both RX and TX lines, which have to be paired with TX and RX accordingly.

Code: [Select]
TX  -----> RX
RX <----- TX


Re: Gps is not recognized by the system
« Reply #7 on: May 23, 2017, 09:04:50 pm »
You need to know about each protocol that you use.  As Mateuze said, serial needs
Tx->Rx
 and
Rx<-Tx.

Just be aware that is not true of all protocols, for instance I2C uses
SDA <-> SDA
    and
SCL <-> SCL

Re: Gps is not recognized by the system
« Reply #8 on: May 23, 2017, 09:26:07 pm »
So to connect in Flexiport which connection will I use?
Tx --> Rx
Rx <-- Tx

f5soh

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Re: Gps is not recognized by the system
« Reply #9 on: May 23, 2017, 09:37:00 pm »
GPS            Flexiport
 Tx -------> Rx (pin4)
 Rx <------- Tx (pin3)

https://librepilot.atlassian.net/wiki/display/LPDOC/GPS+setup#GPSsetup-UbloxGPS

Re: Gps is not recognized by the system
« Reply #10 on: May 23, 2017, 09:45:56 pm »
Okay, thank you very much, everyone for the help.

Re: Gps is not recognized by the system
« Reply #11 on: May 24, 2017, 01:57:28 pm »
I managed to make it work, it was only inverting pins 3 and 4, I used the UBXCenter software, and locked 10 satellites inside the house with a few seconds after it was turned on. Very good this Gps. Many thanks to everyone again.

Re: Gps is not recognized by the system
« Reply #12 on: May 24, 2017, 07:39:41 pm »
Master Satan says:
...

?

Ahhh...  666 posts.  :)  But you will have to post again sometime.   ;D