Tuning

GO buggy GO

shopping list

• Toggle Switch - to swap the buggys programmes running, from following a track, to recognising symbols.
• LDR - 4 LDRs gives more to programme, but also a greater sensitivity when calibrated as they can be compared to enable to buggy to make a greater number of decisions based upon the data they provide.
• Super-bright LEDs - to light the underside of the buggy and provide the LDRs with a steady light source to compare the track against. 

These components were purchased at Maplin:

Superbright LED: http://www.maplin.co.uk/Module.aspx?ModuleNo=220752

LDR: http://www.maplin.co.uk/Module.aspx?ModuleNo=227181

Toggle switch: http://www.maplin.co.uk/Module.aspx?ModuleNo=2340

Motor Testing

Code used to test the motors:

main:

high 1
low 0
high 2
low 3
pause 5000
low 1
high 0
low 2
high 3
pause 5000

goto main

this code was used to make both motors head in the forward direction and after 5 seconds go in the reverse direction.

Software Update

Problems Faced

• Reed switches were not sensitive enough for magnetic tape.
• Only 3 analog to digital converters on chip.

Actions on Problems

• Changed code to suit LDRs.
• Chose to not use the ADC's and plan to use the LDR's digitally. If they provide a voltage of over 2.25V then PICAXE will read as logic 1. If under 2.25V then logic 0 will be read.

Future Intentions and Learning Outcomes

• LDR's will need to be calibrated for light conditions in the room.
• Debug code on buggy testing in order to remove faults and include possible failsafe.
• Include extra code for unique additional functions which will be revealed on competition day.

Current Situation

• Code for both line following and signal reading modes is complete, tested and fully operational.
• Input output variables may change but are easily edited in the code.