LowLevel

THIS PAGE IS ABOUT VERSION 2 LOW LEVEL

Current >> Low Level Version 3

C2- Overview :

The job of C2 and the Low-Level board is to implement the speed and turn profiles generated by the High-Level system. C2 may alternately take input from a joystick, either mounted on the trike or operated remotely by an RC unit, Like most of our current embedded systems, this Board is powered by an Arduino Mega 2560. The power input comes from the 9.6V 2Ah RC car battery (currently not permanently mounted). C2 Low-Level is the board that receives commands from High-Level (the Brain) and uses these to send the correct signals to the Linear Actuators that move our steering and brakes, as well as the main wheel Hub-motor. This separation between High and Low Level means that this architecture can control any vehicle by modifying the Low-level system.

Software:

All current software relating to C2, as well as its main sketch can be found here: https://github.com/elcano/elcano/tree/master/Elcano_C2_LowLevel This software has several functions:

• Read speed and turn profile from C3
• Interrupt on a wheel rotation pulse and compute the speed
• Control the analog throttle and brakes so that the trike moves at the requested speed
• Read a sensor giving the angle at which the wheels are turned
• Turn the trike as commanded.
• Measure the width of pulses from the RC unit and behave accordingly
• Read analog values from an on-board joystick

A supplementary sketch is https://github.com/elcano/elcano/tree/master/TestArchive/MoveActuator. When this program is loaded onto C2, it moves the wheel, toggles brakes, and moves the steering back and forth. This is a useful mechanical test for troubleshooting.

Schematics:

See https://github.com/elcano/elcano/tree/master/Electronics/LowLevel.sch and .brd. The previous version was called MegaShieldDB, with additional functionality on RC_shield. The LowLevel board merges these two.

-- Main.TimK - 2017-04-10