rosserial vs custom serial protocol

[rbridges12]

For our hardware drivers that use serial to communicate from an external processor to our main computer, I found the rosserial package which seems to be the recommended solution. Basically it will make your external processor a ROS node and have it publish/subscribe to data encoded over serial, and then you have a translator node on the main computer which interfaces with that serial connection and translates it into the main ROS network.

Is this something we want to do? Our previous solution as I understand (at least for the IMU) is to implement our own very simple custom serial protocol for sending data, then decode that on a driver node running on the main computer, which would then publish that data to the main network. I worry the rosserial solution could be less reliable, but I don't actually know enough about the characteristics of serial communication to know if that worry is founded. @tabiosg @sashreek1 what do you think?

[tabiosg]

@niwhsa9 actually already brought this to our attention less than a month ago (mentioned in #esw-23)

Here's what I had to say:

"
I took a closer look and yea it looks like it will make code much simpler. My only issues are that 1) hopefully overhead isn't an issue, 2) the stm32 repo is not currently maintained, and 3) I'm not sure if it works for all stm32 chips.
But if we do get this working it'd be very nice.

Here are some links for future reference.
https://github.com/yoneken/rosserial_stm32
https://github.com/yoneken/rosserial_stm32/tree/master/src/ros_lib/examples
"

[tabiosg]

Now for you, the situation is different because if I recall, localization still uses Arduino so it may be worthwhile to use rosserial since I think rosserial for Arduino IS maintained.

[rbridges12]

Ok sounds good, altho I now have a different possible solution. I found this ROS package specifically for this IMU that seems to have a pretty well made python API for it and they suggest using UART mode and just connecting it straight to the computer over USB instead of having an arduino. Assuming this package actually works, is there any reason on the hardware side that we couldn't do this?

[tabiosg]

Not sure what you mean by concerns on the hardware side. Do you mean like system-wise? There is probably no issue - it fits well into our system since it's just USB.

[rbridges12]

Ok sounds good, I'll try it then