# Mav link down when connected to telem with battery **URL:** \ **Category:** ADS-B\ **Created:** [1 February 2021 03:32 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655 "2021-02-01T03:32:03Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![gwm](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/g/94ad74/32.png) [@gwm](https://discuss.cubepilot.org/u/gwm)\ **Post date:** [1 February 2021 03:32 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/1 "2021-02-01T03:32:03Z")
I connected my Orange Cube Here 3 to my raspberry pi using USB, which works well. But I tried to use UART. Connecting the Raspberry pi to Telem 2. Connecting both TX, RX and Ground. Even the 5V+. When I power the external power on my raspberry it works. (Raspberry now is powering the Cube) Now I remove the external power to my raspberry. Connect my raspberry to the same battery source that power the cube. When I turn on it sound exactly the same with the buzz. But when I tried to connect to the flight controller using Mavproxy. it shows Link 1 Down. Anyone knows why? ---
**Author:** ![Alvin](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/alvin/32/1000_2.png) [@Alvin](https://discuss.cubepilot.org/u/Alvin)\ **Post date:** [1 February 2021 07:03 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/2 "2021-02-01T07:03:40Z")
Can you try to remove 5V+ connection between Cube and pi? Also, can you show the circuit diagram/picture? ---
**Author:** ![gwm](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/g/94ad74/32.png) [@gwm](https://discuss.cubepilot.org/u/gwm)\ **Post date:** [2 February 2021 17:14 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/3 "2021-02-02T17:14:50Z")
![Untitled 3](https://discuss.cubepilot.org/uploads/default/original/2X/5/51c25b026b5062bec5b12d39dc568782b2059c4e.png) The diagram is how I connect it. ---
**Author:** ![Alvin](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/alvin/32/1000_2.png) [@Alvin](https://discuss.cubepilot.org/u/Alvin)\ **Post date:** [3 February 2021 03:52 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/4 "2021-02-03T03:52:56Z")
You need some extra setup before communicating via serial [https://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html#setting-up-the-flight-controller](https://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html#setting-up-the-flight-controller) ---
**Author:** ![gwm](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/g/94ad74/32.png) [@gwm](https://discuss.cubepilot.org/u/gwm)\ **Post date:** [3 February 2021 05:51 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/5 "2021-02-03T05:51:39Z")
hi, Yes I did try but it doesn’t work. I assume it as something to do with supplying power to the raspberry might interfere with the signal on the UART Pin on the raspberry. Currently the Raspberry power I connected 5V Ground to GIO pin as well on Pin 2 (5V Power) and Pin 6 (Gnd). Telem 2 Gnd to pin 6, Tx to Pin 10(RX), Rx to Pin 8 (Tx) Maybe I would try supplying power using a Micro USB plug instead of the GIO pin to see if it works. ---
**Author:** ![gwm](https://discuss.cubepilot.org/letter_avatar_proxy/v4/letter/g/94ad74/32.png) [@gwm](https://discuss.cubepilot.org/u/gwm)\ **Post date:** [3 February 2021 06:36 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/6 "2021-02-03T06:36:19Z")
I tried using battery to micro USB to power the raspberry, it doesn’t work as well. The only way that it will work is when I connect the raspberry to a separate power source from the Orange cube. Or if its the same power source, then only USB works but not serial. I really don’t know why. ---
**Author:** ![Alvin](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/alvin/32/1000_2.png) [@Alvin](https://discuss.cubepilot.org/u/Alvin)\ **Post date:** [3 February 2021 07:19 UTC](https://discuss.cubepilot.org/t/mav-link-down-when-connected-to-telem-with-battery/5655/7 "2021-02-03T07:19:01Z")
You can’t power the raspberry pi by its gpio