Help! How to detect obstacles using ping))), and making the servos turn for avoidance

kolai

Hello everyone, I'm a newbie on obstacle sensing using the ping))) sensor. I'm trying to make obstacle sensing boe - bot w/ 3 sensors, namely 2 - IR emitter & Receiver and the ping))) sensor. I didn't attach the ping sensor to the servo because the purpose of the ping sensor is only to detect forward obstacles and the IRs for the left and right obstacles. I really just can't get it to work, I've used the 2 IRs and it went well. What I want next is to add a middle sensor('ping)))') to detect forward obstacles, but as I try to study the codes from 'Mini Projects', I get so confused on how to use it, and even the 'RoamingWithPing.bs2' gave me a headache.

Please Help. :blank:

Here is my code

' {$STAMP BS2}
' {$PBASIC 2.5}
'Maze Traversal

DEBUG " Program Running! "

irDetectLeft VAR Bit
irDetectRight VAR Bit

cmConstant CON 2260
pulseLeft VAR Word
pulseRight VAR Word
distance VAR Byte
cmFinal VAR Byte

FREQOUT 4, 30, 5000

GOSUB Read_Ping
GOSUB Calc_Distance

DO

IF (cmFinal < 3) THEN
pulseLeft = 650
pulseRight = 850

FREQOUT 8, 1, 38500
irDetectRight = IN0

FREQOUT 9, 1, 38500
irDetectLeft = IN10


ELSEIF (irDetectRight = 0) AND (irDetectLeft = 1)THEN
pulseLeft = 650
pulseRight = 650
HIGH 1

ELSEIF (irDetectRight = 1) AND (irDetectLeft = 0)THEN
pulseLeft = 850
pulseRight = 850
HIGH 15

ELSE
pulseLeft = 850
pulseRight = 650
LOW 1
LOW 15

ENDIF

Read_Ping:
PULSOUT 3, 5 ' Start Ping)))
PULSIN 3, 1, distance ' Read echo time
RETURN

Calc_Distance:
cmFinal = cmConstant ** distance ' These are the whole measurements


PULSOUT 13, pulseLeft
PULSOUT 12, pulseRight
PAUSE 20

LOOP


Thanks

Mike Green

"Roaming with PING" may give you a headache, but you have to understand how it works and how the IR Roaming program in the Robotics manual works.

There are only a few conditions possible. The right IR detector can detect something (or not). The left IR detector can detect something (or not). The PING can detect something (or not). That's only 8 possibilities. First you have to define what you want your robot to do under those 8 combinations of conditions. It's simpler than that because some of the 8 possibilities are mirror images of each other (left vs. right) and, in some cases, there are "don't care" conditions. Work out those 8 combinations and the robot's actions associated with each one and let us know what you come up with.

kolai

Thank you very much Mike, I'll work on it.

kolai

sir mike, what would be its algorithm if your ging to use the 3 sensors for maze traversal.
Plwase Help

kolai

Trying to solve this kind of problem was really hard for me:
and finally i got it.

Its a prototype but it works;

{$STAMP BS2}
' {$PBASIC 2.5}

time VAR Word
cm VAR Word
in VAR Word
ft VAR Word
cmcons CON 2260
incons CON 890
ftcons CON 74

counter VAR Byte
irDetectLeft VAR Bit
irDetectRight VAR Bit

DO

PULSOUT 15, 5
PULSIN 15, 1, time


cm = cmcons ** time
in = incons ** time
ft = ftcons ** time

FREQOUT 9, 1, 38500 ' Check IR Detectors
irDetectLeft = IN10

FREQOUT 8, 1, 38500
irDetectRight = IN0


DEBUG HOME, "time = ", DEC5 time
DEBUG CR, "cm = ", DEC3 cm, "cm"
DEBUG CR, "in = ", DEC3 in, "in"
DEBUG CR, "ft = ", DEC3 ft, "ft"

IF (((in = 3) AND (cm = 8)) OR (in = 2) OR (in = 1) ) THEN 'distances which the ping will react
FREQOUT 4, 200, 7000
GOSUB Back_pulse
GOSUB Right_pulse
GOSUB Right_pulse
GOSUB Right_pulse


ELSEIF (irDetectLeft = 0) AND (irDetectRight = 0)THEN
GOSUB Forward_pulse
HIGH 1
HIGH 11



ELSEIF (irDetectLeft = 0)THEN
GOSUB Back_pulse
GOSUB Right_pulse
HIGH 11


ELSEIF (irDetectRight = 0) THEN
GOSUB Back_pulse
GOSUB Left_pulse
HIGH 1

ELSEIF (irDetectLeft = 1) AND (irDetectRight = 1)THEN
GOSUB End_pulse
LOW 1
LOW 11

ELSE
LOW 1
LOW 11
PULSOUT 13, 850
PULSOUT 12, 650
PAUSE 15

PAUSE 100


ENDIF

LOOP

Forward_pulse:
FOR counter = 0 TO 7
PULSOUT 13, 850
PULSOUT 12, 600
PAUSE 20
NEXT
RETURN

Right_pulse:
FOR counter = 0 TO 3
PULSOUT 13, 850
PULSOUT 12, 850
PAUSE 20
NEXT
RETURN

Left_pulse:
FOR counter = 0 TO 3
PULSOUT 13, 650
PULSOUT 12, 650
PAUSE 20
NEXT
RETURN

Back_pulse:

PULSOUT 13, 650
PULSOUT 12, 850
PAUSE 15

RETURN


Stop_pulse:
PULSOUT 13, 750
PULSOUT 12, 750
PAUSE 50
RETURN

End_pulse:
FOR counter = 0 TO 5
PULSOUT 13, 850
PULSOUT 12, 600
PAUSE 50
NEXT

RETURN

Code: