Tidied spidertank and added showcase readme

examples/showcase/README.md

@@ -0,0 +1,26 @@
+# Yukon Micropython Showcase Examples <!-- omit in toc -->
+
+This folder contains a collection of *Showcase* examples, that bring together concepts presented by individual board and module examples to create functional projects.
+
+- [RC Rover](#rc-rover)
+- [Spider Tank](#spider-tank)
+
+
+## RC Rover
+[rover/main.py](rover/main.py)
+
+A showcase of Yukon as a differential drive rover. It uses two Big Motor modules, one to control the left side motors, and the other to control the right side motors.
+
+There is a LED Strip module controlling left and right strips that represent each side's speed as a colour from green -> blue -> red. Additionally, there is a proto module wired up to a buzzer to alert the user to the battery voltage getting too low, which also exposes the UART for connection to a bluetooth serial transceiver.
+
+The program receives commands from the JoyBTCommander Android App and converts them to motor speeds. it also sends the voltage, current, and temperature of Yukon back to the App.
+
+
+## Spider Tank
+[spidertank/main.py](spidertank/main.py)
+
+A showcase of Yukon as a hexapod robot, with 3 degrees of freedom per leg. It uses two Serial Bus Servo modules, one to control the left side servos, and the other to control the right side servos.
+
+There is also a proto module wired up to a buzzer to alert the user to the battery voltage getting too low.
+
+The program performs inverse kinematics for each leg, with the target points following a tripod walking gait.

examples/showcase/spidertank/lib/leg_ik.py

@@ -5,6 +5,21 @@
 import math
 from collections import namedtuple
 
+"""
+This file contains a collection of classes and functions for performing
+the inverse kinematics (IK) of a 3 degree of freedom robot leg.
+
+The central class of this implementation is Vector3, which is used to store
+3D coordinates. The axes of these coordinates follow the left hand rule:
+* X = right/left
+* Y = up/down
+* Z = forward/back
+
+This IK implementation is derived from understandings gained by
+Christopher "ZodiusInfuser" Parrott, during the development of:
+https://github.com/ZodiusInfuser/TrueWalkSimulator
+"""
+
 Limits = namedtuple("Limits", ("min", "max"))
 
 

examples/showcase/spidertank/main.py

@@ -12,12 +12,15 @@
 from leg_ik import Vector3, calculate_ik_3dof, Limits, rotate_y
 
 """
-This is a showcase of how Yukon can be used to drive a 3 degree of freedom hexapod robot.
+A showcase of Yukon as a hexapod robot, with 3 degrees of freedom per leg.
 It uses two Serial Bus Servo modules, one to control the left side servos,
 and the other to control the right side servos.
 
-There is also a proto module wired up to a buzzer to alert the user to the battery
-voltage getting too low.
+There is also a proto module wired up to a buzzer to alert the user to the
+battery voltage getting too low.
+
+The program performs inverse kinematics for each leg, with the target
+points following a tripod walking gait.
 
 Press "Boot/User" to exit the program, only if the buzzer is not sounding.
 If the buzzer sounds, disconnect power as soon as possible!