# Using Mavros(.launch) Bring information of Crazyflie2.0 to Terminal

**URL:** <https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147>\
**Category:** Uncategorized\
**Created:** [January 9, 2017, 8:37pm UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147 "2017-01-09T20:37:38Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Taein](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/ed8c4c/32.png) [@Taein](https://discuss.px4.io/u/Taein)\
**Post date:** [January 9, 2017, 8:37pm UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147/1 "2017-01-09T20:37:38Z")

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====My development environment====

1. Ubuntu 14.04
2. QGC 3.1.0 v
3. Crazyflie 2.0 (Uploaded Px4 firmware)  
4.CrazyRadio PA  
5.ros-indigo, mavros-extra.  
================================

Question ]

I would like to use “mavros” to output the sensor value or data of Crazyflie to the terminal. However, “CrazyRadio PA” does not support serial connections (CrazyRadio PA uses  
a proprietary protocol called “CRTP”). So I have to use the ‘mavros.launch’ form, and I’m having trouble with fcu\_url, gcs\_url configuration . Is there a solution?

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**Author:** ![dennisss](https://discuss.px4.io/user_avatar/discuss.px4.io/dennisss/32/3541_2.png) [@dennisss](https://discuss.px4.io/u/dennisss)\
**Post date:** [January 9, 2017, 10:22pm UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147/2 "2017-01-09T22:22:40Z")

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The PX4 implementation allows communicating via Mavlink over CRTP. See the end of [http://dev.px4.io/hardware-crazyflie2.html#wireless](http://dev.px4.io/hardware-crazyflie2.html#wireless) for information on how to do this. Then mavros can be connected as if there was an fcu on local port 14550

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**Author:** ![Taein](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/ed8c4c/32.png) [@Taein](https://discuss.px4.io/u/Taein)\
**Post date:** [January 10, 2017, 4:44am UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147/3 "2017-01-10T04:44:26Z")

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![](https://discuss.px4.io/uploads/default/original/1X/9ea8d0a271dcb7efbd4eea9d1a1c59cb851a2c21.png)

@dennisss

Thank you for your help!. So I’ve tried many, but I still have difficulties with url configuration. I’ll show you my specific situation through image upload. The image is the xml source of mavros.launch.

p.s i use cfbridge

have a nice day denniss!

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**Author:** ![dennisss](https://discuss.px4.io/user_avatar/discuss.px4.io/dennisss/32/3541_2.png) [@dennisss](https://discuss.px4.io/u/dennisss)\
**Post date:** [January 10, 2017, 1:31pm UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147/4 "2017-01-10T13:31:47Z")

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I haven’t used mavros in a while, but I’m pretty sure you don’t need the `gcs_url` argument as that is usually for when you are using qgroundcontrol as well (so get rid of that line). The `fcu_url` should be udp based, so something like `<arg name="fcu_url" default="udp://:14550@:14555" />` should work. That would specify to listen on local 14550 for messages and send outbound messages to 14555.

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**Author:** ![Taein](https://discuss.px4.io/letter_avatar_proxy/v4/letter/t/ed8c4c/32.png) [@Taein](https://discuss.px4.io/u/Taein)\
**Post date:** [January 11, 2017, 4:15am UTC](https://discuss.px4.io/t/using-mavros-launch-bring-information-of-crazyflie2-0-to-terminal/2147/5 "2017-01-11T04:15:34Z")

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Oh, I got it! I understand your reply.  
Now, I will apply that to my project.  
Thanks @dennisss!