Need help setting up my ultrasonic distance sensor

[mark_s]

Take a look at this page,

http://www.parallax.com/dl/docs/prod...tance28015.pdf

Regards
Mark

[Kamikaze47]

You need to set the mode and distance threshold by sending the correct command serially to the sensor. You want 9600 baud, no parity, one stop bit. The SEROUT section of the PBP manual will tell you how to do this, and the PDF you provided in your OP will tell you what commands you need to send.

The best way to get help here is to try it, and if what you try doesn't work, post the code here and i'm sure lots of help will be forthcoming.

[Megahertz]

Here goes my code for 16F676. Used this IC because I can program it in PICKIT2 & also I have jumpered my sensor around it.

Include "modedefs.bas"
DEFINE     NO_CLRWDT    1
DEFINE          OSC     4       ' OSCCON defaults to 4MHz on reset
DEFINE OSCCAL_1K 1

@ __Config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _PWRTE_ON & _MCLRE_OFF & _BODEN & _CP & _CPD

PAUSE 50
Tx Var PortA.1
Rx Var PortA.0
power var PortC.1
	TRISA = %000001
	TRISC = %000001
	CMCON = 7
	ANSEL = 0
      OPTION_REG = %10000111  ' RAPU = off, PS 1:256 to TMR0
	PORTA=0
	PORTC=0
	' setup iZCD to interrupt on change
	INTCON = 0

; PortC.0 = PWM Receive ; ; ; ; ; PortC.1 = Power_On ; ; ; ;  PortA.0 = Receive Pin ; ; ; ; PortA.1 = Transmit Pin ; ; ; ; PortA.2=Trigger Pin

main:
High power
pause 100
Serout Tx, N9600, ["0x44+0x00+160+ ???"]	;	To set lower threshold distance to appx 3 meters. What should be the SUM & how do you calculate it?
Serout Tx, N9600, ["0x44+0x01+250+ ???"]	;	To set upper threshold distance to appx 5 meters
Serout Tx, N9600, ["0x44+0x02+0xaa+ ???"] ; 	To set operation mode to autonomous mode

	if PortA.2=0 then
		High PortC.2 ; led 1
	else
		high PortC.5 ; led 2
	endif
goto main
end

1) How do you calculate the SUM? any example please
Once I get to the next point, I will update here if I get stuck. Thanks

[Kamikaze47]

try something like this (taking your 1st serout line as an example):

Serout Tx, N9600, [$44,$00,$A0,$E4]

$A0 is just 160 in hex.

To work out the sum: $44+$00+$A0=$E4

If the sum is bigger than $FF then you take just the lower byte. e.g. if the sum came to $01A2, then you just use $A2.

[Megahertz]

Hi, I tried this:

main1:
High power
Pause 100
Serout Tx, N9600, ["0x44+0x00+0xA0+0xE4"] ;To set lower threshold distance to appx 3 meters
Pause 100
Serout Tx, N9600, ["0x44+0x01+0xD1+0xFE"] ;To set upper threshold distance to appx 5 meters
Pause 100
Serout Tx, N9600, ["0x44+0x02+0xaa+0xF0"] ; To set operation mode to autonomous mode
main:
	if PortA.2=1 then
		high PortC.2
	else
		 toggle PortC.5
	endif
pause 50
goto main
end

And also this:

Serout Tx, N9600, [$44,$00,$A0,$E4] ;To set lower threshold distance to appx 3 meters
Pause 100
Serout Tx, N9600, [$44,$01,$D1,$FE] ;To set upper threshold distance to appx 5 meters
Pause 100
Serout Tx, N9600, [$44,$02,$aa,$F0] ;To set operation mode to autonomous mode

but no luck - any advise?

[Acetronics2]

Hi,

The question is ...

did you use a RS232 chip on YOUR board ??? ( like in the datasheet scheme )

more ...

Could you , please , attach YOUR scheme ???

Alain

[Megahertz]

Hi,

The question is ...

did you use a RS232 chip on YOUR board ??? ( like in the datasheet scheme )

more ...

Could you , please , attach YOUR scheme ???

Alain

Hi, here is my hardware photo, just my sensor jumpered to my PICKIT2 in the following configuration:
; PortC.0 = PWM Receive ; ; ; ; ; PortA.0 = Receive Pin ; ; ; ; PortA.1 = Transmit Pin ; ; ; ; PortA.2=Trigger Pin
PWR_ON is directly connected to 5V on the PICKIT2
Also I am using TTL I/O, I have arranged the jumpers accordingly.