PyArm Journal
Recently, I purchased the JJRobots Scara Robot Arm (also called PyArm). I purchased the kit so that I could validate the arm before attempting a creation from the open-source files. (Best to know it works before investing a great deal of time and money.) This is a log of the good and bad of the purchase.
Good:
· Design is straight forward.
· The Arm Assembly is VERY WELL documented.
· Arm movement is smooth except for the gripper rotation servo. (I could have a faulty servo)
· Arm is relatively inexpensive.
· Initial assembly can be completed in 1 ½ hours.
Bad
· The kit shipped with a forearm component that was too short. (There are updated STL files for the forearm, but the part was not updated in the kit.)
· The shipping took an extremely long time to clear customs. It took 5 weeks from order to receipt in the US.
· Documentation: Details for updating the Devia Control Board from the Arduino IDE was not where I expected it. Finding all the components for updating the board firmware was much more challenging than it needed to be. Took about 1 ½ hours total. (I will detail this later in the article).
· Documentation: The Control App user guide is a high-level overview of the app but does not provide a quick start guide on connecting and testing the arm.
· The Control App is written in Python 2.7 and has not been updated.
· The JJRobots site does not show progress on this arm since late 2019 although there are some posts in the forum.
Some additional comments on the documentation. For me, there should be two levels of documentation for a project like this.
· Level one should be getting it setup and confirmed to work.
· Level two should be details of enhanced features and prospective capabilities.
I would have liked to see a bit more on level one when trying to get everything working.
UPDATING the DEVIA CONTROL BOARD
There is a nice little section in the pyBot Control APP code + Arduino code document called HOW TO UPLOAD the ARDUINO CODE to the DEVIA CONTROL BOARD
Just what your looking for right….
Maybe, but not so fast. It is missing one BIG piece of information. WHICH BOARD LIBRARY DO WE NEED?
The board is an ARM Cortex MI Microcontroller (Arduino Zero) — To connect to it we need to load the Arduino SAMD Board Library Version 1.8.10. It would have been nice for this to be in the instruction!
Instead, I spent the next hour+ digging through the JJRobots Site until I found a reference to the correct library in the image under DEVIA Control Board TEST code
Final thoughts for this post.
There is much to like about the JJRobots PyArm. The physical structure is pretty good and it will be a good platform from which to test. The Control app demonstrates many capabilities that I have not yet been able to fully investigate but looks promising….