# Pixhawk 4 Mini Telem 1 Companion Computer: high packet loss

**URL:** <https://discuss.px4.io/t/pixhawk-4-mini-telem-1-companion-computer-high-packet-loss/10235>\
**Category:** Pixhawk\
**Created:** [March 29, 2019, 4:42pm UTC](https://discuss.px4.io/t/pixhawk-4-mini-telem-1-companion-computer-high-packet-loss/10235 "2019-03-29T16:42:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![LiveActionCactus](https://discuss.px4.io/letter_avatar_proxy/v4/letter/l/d6d6ee/32.png) [@LiveActionCactus](https://discuss.px4.io/u/LiveActionCactus)\
**Post date:** [March 29, 2019, 4:42pm UTC](https://discuss.px4.io/t/pixhawk-4-mini-telem-1-companion-computer-high-packet-loss/10235/1 "2019-03-29T16:42:01Z")

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Hi,

I have a Pixhawk 4 Mini and have been using a Raspberry Pi Zero companion computer on Telem 1. I recently noticed that the physical connection between my Pixhawk and the Pi Zero was dropping 70-90% of my packets. About ~70% when I set a 115200 BAUD and ~90% with 921600 BAUD. Might there be a problem with the grounding? Has anyone else experienced high packet loss?

Also, I noticed that in APM they have RTS/CTS control that they recommend disabling. I’m not doing flow control over my UART connection. Is there something in the Pixhawk parameters that I would need to change?

Thanks,  
Pat