Need help setting up my ultrasonic distance sensor

[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.

[Acetronics2]

Hi,

OMG ...

I also think you are exceeding the Pickit sourcing authorized current ... Especially when " pinging " ...

Alain

[Megahertz]

Hi,

OMG ...

I also think you are exceeding the Pickit sourcing authorized current ... Especially when " pinging " ...

Alain

Oops! will try everything again with seperate supply and update here. May be this is the reason that it is not working.