picaxe command

PICAXE Commands (valid all sizes):
Output - high, low, toggle, pulsout, let pins = Please see the BASIC Commands (v3.5)
Input - if…(and/or)...then, readadc, pulsin, button help file for more detailed syntax help
Sound - sound and information about each command.
Serial - serin, serout
Program Flow - goto, gosub, return, branch
Loops - for…next
Mathematics - let… (+, -, *, **, /, //, max, min, &, |, ^, &/, |/, ^/ )
Variables - if...then, random, lookdown, lookup
Data memory - eeprom, write, read
Delays - pause, wait, nap, sleep, end
Miscellaneous - symbol, debug

Light Dependant Resistors

A light dependant resistor (LDR), is an analogue sensor which detects light and changes resistance accordingly. Versions can be bought where the resistance either increases with light, or dark.
They would work in this project by detecting the contrast between the light background and the dark strip the buggy hass to follow.

Typical dimensions are shown on the diagram.

Reed Switches

A reed switch is a sealed glass tube, with two contacts inside it. It is a magnetic switch, either open or closed. When a magnetic field is applied to the component, the two contacts attract, and close the switch. When the field is removed, the natural spring in the contacts forces them apart again.

Typical dimensions are 10- 15mm in length and around 2.2mm diameter, not including the connecting legs

If a magnetic field strong enough to operate them cannot be guaranteed, they cannot work

Meeting 2 ( 22/04/10)

Today the group has come together to discuss how to create the chassis . The circuitry has been made however, the program is still being created and is nearly finished. Therefore, by the time of our next meeting, we have to :

• Create the chassis whilst making sure there is enough space for the circuitry.
• Complete the program , even if the buggy does not fully work yet!

Autonomous Vehicles - Land , Sea & Air.

Short Examples of projects or products which have the incorporation of autonomous technology in air , Sea and Land are given below.


Air

This project and research started in southern california in 1991 with the creation of the autonomous flying vehicle project and is still in operation until this very day. A succession of flying vehicles were made from the AFV ( Autonomous Flying Vehicle ) in 1991 which can be seen above to the AVATAR ( Autonomous Vehicle Aerial Tracking and Retrieval ) which was created in 1994.

Sea

The development of Indias first Autonomous Under Water Vehicle is expected to complete its final underwater trial by august 2010 . Autonomous Underwater technology is vigorously persued in many technologically advanced countires such as australia, germany, russia, korea and japan.

The creation - ' AUV 150 ' is a cylinderical carrier which is imbedded with advanced power, propulsion, navigation and control systems. Two arrays of cross fins have also been fixed at the two ends to provide additional stability to the AUV. A lithium plymer battery powers the vehicle and a pressure hull contains its electronics and energy system. The vehicle can be seen below.
































The use of the vehicle is to carry out an underwater mission without assistance from an operator on the surface. The vehicle determines its own geographical position with navigational sensors .



Land

The audi pikes peek TTS Autonomous vehicle which also has been given the nickname shelley is an autonomous vehicle capable ot completing the pikes peak international hill climb in a reasonable time using rally driving techniques.

The main team behind this operation was the volkswagen electronic research lab signifying that control systems within companies is playing a greater role in todays real world applications.

Autonomous Vehicles

An autonomous Vehicle is the type of vehicle that drives on its own. They are currently being devoloped by companies and universities all over the world !

Autonomous vehicle control uses external sensors of the environment to navigate or carry out a particular task. This is different to normal vehicles which demand an input to carry out a set job.

The use of such vehicles can reduce costs and has other advantages. Doing repetetive tasks manually can require certain costs hence more labour. However, the advantage of utilizing the autonomous vehicle is that the tasks would not need to be supervised ( safety ) and can be done over and over again without the vehicle 'getting tired'. This can lead to greater efficiency.

Recently the concept of such a vehicle has flourished into the control engineering sector and the expansion of such vehicles on air, land and sea may shape the future of many engineering concepts which are used today.

comparing

' PICAXE-18X TPIC6259
'
' Output5 (term 11) ----------------- /G (term 13)
' Output4 (term 10) ----------------- CLR (term 19)
' Output3 (term 9) ------------------ D (term 18)
'
' Output2 (term 8) ------------------ S2 (term 12)
' Output1 (term 7) ------------------ S1 (term 8)
' Output0 (term 6) ------------------ S0 (term 3)
'
' Uses about 128 bytes and could probably be accommodated in a less expensive
' PICAXE-18A.

initial programme using LDR

it is so rough one. we need to develop this programme.
Basically using the LDR and check the value.
given the condition as below
the picaxe read a light sensor measure (sensor 0) and show measures from 0 to 250, but if we suppose that 0 is 0% and 250 is 100% (presence of light)



LDR value 0 to 250 it will show 0 to 100%, also shows number of readings taken, it reads the LDR once per second.

Percentage = ldr * 100 / totalvalue

#picaxe 18x
symbol Percentage = b0
symbol ldr = b1
symbol Readings = b2 
symbol TotalValue = 250

Readings=0
serout 7,n2400,(254,1)
pause 30
do
readadc 1, ldr
percentage = ldr * 100 / TotalValue
inc Readings
serout 7,n2400,(254,128,"Reading #",#Readings)
pause 30
serout 7,n2400,(254,192,"Light = ",#Percentage,"% ") 
pause 1000
loop 

Outer shell idea

instead of having our robot looking simillar to this....

i was thinking of using one of these as i can get hold of one....
the dimenisions are ~42cm by 20cm which will easily fit all the circuitry and controllers etc.
just need to source a suitible material for the base as i dont think it will be supplied...

chassis - intial findings

As we have not chosen a sensor type, it is hard to actually design the chassis but we have been looking into the following ideas

2 large wheels mounted towards the rear of the buggy, with one small (non-powered) wheel at the front. Similar design to the Robin Reliant (but more stable!).

OR

2 large wheels mounted at each side (centre).

OR

even two large wheels towards the front of the chassis and one small wheel at the rear. this small wheel could act as a 'rudder' like on a boat.

Sensor type research

(WEEK 1 WORK LATE POST!)
As a group, we have narrowed the down the possible sensors we can use for the robot.

Miniature Reed switches - (Magnetic sensor) still not sure whether the supplied sensors are up to the job, so we will be carrying out further testing in due course. If we can get this to work then the programming side of things will be easier (no ADC required etc). May also have to purchase strong type of sensor (more sensitive).

L.D.R - widley used and 'tried and tested' in L.F.R's so there is a lot of reasearch available.

INFRA RED - use of these sensors will result in a relatively easy circuit, but in the majority of the cases LDRs are preffered.

Optical sensors - again we will have to look into this aswell, but having seen them in action, i am very impressed.

simple programing

POSTED ON BEHALF OF JUNGKYOO PARK
This is a simple type of command.
It shows how to follow a line. It is really simple program using no speed control.

init: pause 1000

main:
if b1 is on then go_f ‘ forward
if b2 is on then go_l ‘ left
if b6 is on then go_r ‘ right
goto go_s ‘ stop as no line nearby
go_f: let pins = %10100000 ‘ go forward
goto main
go_l: let pins = 100000 ‘ go left
goto main
go_r: let pins = %10000000 ‘ go right
goto main
go_s:
let pins = 000000 ‘ stop - not line anymore
goto main

meeting 1 ( 14 /03/ 2010)

The group has come together to discuss how to go about making the commands on the pixace program.

Points made were

• The program should be made using case statements as it is something we are familiar with
• Whilst the program is being made, james would make the circuitry .

Just two basic steps are being taken this week towards the project .

Gantt Chart

On the initial group meeting , this gantt chart was designed to assign different members of the team with different tasks to be completed at specific dates.

Project launch

Team list:

Kaiho Sy
Jungkyoo Park
Shazad Hussain
James Woods
Romi Dhillon

3 mar 2010