Tony is a Geek

I finally found the TurtleBot3 robot!  It was in a box, under a desk, hidden away.  I thought I'd lost it. Turns out I bought this a LOT longer ago that I remember: https://tonyisageek.blogspot.com/2021/10/turtlebot3-arrived-and-well-i-couldnt.html https://tonyisageek.blogspot.com/2021/10/turtlebot3-status-update.html It turns out that when I installed and set this all up before, the world has moved on quite significantly and the versions of everything have moved on. So I did what anyone would do... I wiped the SD-Card and started the installation again from scratch. What it did need was the ability to install all the graphical front-end software onto a "decent" laptop - so I repurposed the IBM ThinkPad as per the instructions and then proceeded to basically follow the instructions for installing onto the device itself. PC install instructions :  https://emanual.robotis.com/docs/en/platform/turtlebot3/quick-start/#pc-setup Raspberry Pi installation instructions :  ht...

To some people this information maybe old hat - if however, like me you've been a little busy for the past, well, the past "while" and have only just gotten back to your RPI4 projects, then this might be news to you - and if it is, I'll save you some "Googling"....  First of all, the RPi4 has been in short supply since the pandemic, so that was the first reason this has taken me so long to get around to, but alas I did indeed end up getting my RPi4 from pimoroni or was it thepihut ?, either one is a great place to know about. I purchased this little, well they call it a dog, but the head/ears make it look more like a cat to me, so I shall refer to it as a robot cat from now on. https://github.com/Freenove/Freenove_Robot_Dog_Kit_for_Raspberry_Pi I put it all together, connected all the servos, did all the wiring etc..etc... and then I did put an RPi3 on it I believe to initially set it up.  I got the basics working from the github repo supplied python code. ...

Well.....I seem to have made "some" progress...of sorts.  I've managed to get the turtlebot3 software running correctly on the robot itself.  I have a Virtual Ubuntu 20.04 machine running ROS2 foxy edition and using all the OOTB stuff it seems to be behaving itself. I have created a map using SLAM and used the Navigator2 to click around and get the turtlebot3 to plot a course and move around avoiding obstacles as well as "new" obstacles, like the cat suddenly appearing in front of it.  It seems to handle it well. ( A bit like a certain "Routing Widget v2.1" ;-) ) However...moving over into the ROS2 coding side of things, I had to go back into refresher-land for a day or two (I really do recall doing all of this back in 2017/2018, the memories are still there!). If I do a direct call from the command-line: ros2 topic pub --once /cmd_vel geometry_msgs/msg/Twist "{linear: {x: 2.0, y: 0.0, z: 0.0}, angular: {x: 1.0, y: 0.0, z: 1.8}}" publisher: b...

 I originally ordered the RPi4 version; however I was contacted by Sparkfun.com to say that was not in stock and there was a min. of 2 weeks lead time due to worldwide delivery delays etc... Initially, I thought, "tch! typical!", then the nice support person asked if I wanted to use an RPI3 version instead, as they had 1 of those in stock and basically the kit is exactly the same, it's just a different RPi. Well....I already have an RPi4 inside the Robot Dog/Cat from Freenove....so, I could just swap that out if I really needed the performance....so, I agreed (with a little discount ;-) ) and well, the TurtleBot3 arrived the next day. Here's some images of me being on conference calls and making the TurtleBot3 on my home/work desk - it was pretty simple/easy - however, my only observation was the lack of clear instructions that should show putting little nuts into the bottom/insert of the PCB board holders, once I figured that out all the PCB boards were then nice and...