How to view topics from Marvelmind through ROS?

[watzshakinbacon]

Hello, everyone. I'm new to ROS, and I'm using Python to code my Raspberry Pi. I have the .cpp file (subscriber test) from the Marvelmind website, but since it's in C++, I'm not completely sure how to interpret it. I'm trying to find out the topics that are published by the hedgehog (to get the x and y positions).

I tried to plug in the hedgehog into my RPi and checked rostopics list, but nothing from the hedgehog was listed. Any advice would be greatly appreciated!

[smoker77]

Hello,
The ROS package ('hedge_rcv_bin' publisher) publishes mobile beacon coordinates data in the topic '/hedge_pos_a'.
Here you can see fields of the message for this topic:
https://bitbucket.org/marvelmind_roboti ... ew-default
The message includes address of hedgehog, timestamp and X,Y,Z coordinates.

[watzshakinbacon]

Thank you, smoker77.

Are there any examples to publish and subscribe to these position topics using Python? I've only seen the C++ examples so far. I found this repo (https://bitbucket.org/marvelmind_roboti ... y/overview), but those examples only print directly to the terminal rather than using the publish/ subscribe model.

[smoker77]

You not need to publish anything to the Marvelmind topics, 'hedge_rcv_bin' should publish all data. But you may be needed to implement subscriber. Now we have only example of the C subscriber (subscriber_test), Python subscriber is not available yet.
Please refer to ROS tutorial to write your own subscriber:
http://wiki.ros.org/ROS/Tutorials/Writi ... 8python%29

[paxtonleiny]

Data about mobile beacon coordinates are made available in the topic '/hedge_pos_a', as published by the ROS package ('hedge_rcv_bin' publisher).

[airplanelinnet]

You do not need to publish anything to the Marvelmind subjects, as 'hedge_rcv_bin' will automatically publish all data. However, implementation of subscriber may be required. Currently, only an example of a C subscriber (subscriber_test) is available; a Python subscriber is not yet accessible.