I have a raspberry pi stack (containing 4 raspberry pis). I have a single GPS with serial and I2C output. I want the supply the GPS information to all the 4 raspberry pis simultaneously. Is it possible to short the RX of all 4 raspberry pis and attach the TX of GPS module to them? Is there any other way I can supply GPS information form a single GPS to multiple raspberry pi's simultaneously?

EDIT: I have shorted out the RX pins of Raspberry Pi zero W (GIOP15/ PIN10) and connected them to the TX of the GPS. The Pi's also have a common ground

  • you can receive data from GPS with all 4 RPi, but you can send data to the GPS module from only one RPi ...... if the software, that you are using, expects handshaking with the GPS module, then the multiple connection will not work
    – jsotola
    Commented Sep 6, 2018 at 21:19
  • I connected RX pins of all 4 Raspberry-Pis together and one of the raspberry pis started crashing during system start. I disconnected them and it works fine. How do I connect them together Commented Sep 6, 2018 at 21:41
  • 1
    Please edit your question to detail the connections you have made.
    – joan
    Commented Sep 6, 2018 at 22:07
  • 1
    please provide make and model of GPS module .... or a link to website that sells it
    – jsotola
    Commented Sep 7, 2018 at 0:32
  • Perhaps you could have one Pi sync with the GPS module and have the other Pi's NTP with the synchronized one.
    – BobT
    Commented Sep 7, 2018 at 3:20

1 Answer 1


You need to connect the Pi grounds as well as the signal lines. The signals need to be compared against ground to see if they are high or low.

Perhaps daisy chain pin 6 (a ground pin) between all Pis.

  • I forgot to mention that the Pi's have a common ground as well. So basically, the grounds and the RX pins are common. Still, it doesn't work. The error occurs during boot. If I disconnect the RX pins of the Pi's, every thing works fine Commented Sep 7, 2018 at 16:15

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