Pi Wars 2021 - finally an update!

It has taken a while, but finally, we are able to provide an update.  A lot has been happening over the past few months, but it has been a struggle putting it all together.  The older boys - Ben and Jerry, have been pre-occupied with their A level and GCSE mock exams, leaving just little Danny (now aged 7) as the main helper!

Not much has changed to the 'mechanics' of Dan-ED.  The basic design is the same as last year but we have upgraded the batteries to Samsung 30Q 18650 Li-Ion.  The old batteries just could not cope anymore with the high current drain when moving around.

We have focused initially on the 'Up the Garden path' challenge, modifying our previous 'Arena' to accommodate the course.  The pi-wars organisers were insistent that it should be 1500mm x 1500mm.  Our previous arena was 1200mm x 1200mm (cut from standard 8ft x 4ft plywood sheet).  Luckily we were able to use two of the walls to extend the arena floor.

Dan-ED Arena - with floor extended to 1500 x 1500mm

For the challenge we used white insulation tape to create the 'course' as per the organiser's requirements.  

Dan-ED works well in 'line follower' mode, using 2x line follower sensors in the base.  However, the branches presented difficulties.  We initially masked off the branches with black tape to check Dan-ED could follow the bends correctly.  After some 'tuning' of the code by Jerry it worked quite well.

Following the course - with branches 'masked off' - it worked well!

We then modified the code to help Dan-ED decide which branch to follow.  A simple approach using a 'timer' was adopted.  This simply turned off either the left or right line follower sensor just before it reached a branch.  This ensured Dan-ED would select the correct branch.

Test run with branch selection code added - it works well except it is following the course the wrong way round - arghhhh!

We are now modifying the code for Dan-ED to follow the course the 'correct' way round!  Meanwhile we have decided to switch to the 'DIY obstacle challenge' now that it is half term and the older children have more time to help.