HC-SR04 Ultrasonic Sensor

Adolfo · 2020-01-29 16:37

I have tried different codes to operate the HC-SR04 sensor and it only reads zeros, the board I am occupying is BASIC Stamp HomeWork Board USB and the codes that I have used are the following:

Code 1:

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

time VAR Word

main:

DO
LOW 9
PULSOUT 9, 20
PULSIN 8, 1, time
time = time ** 2251
DEBUG CR, "Distance = ", DEC4 time, " cm"
PAUSE 5
LOOP

Code 2:

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

time VAR Word

main:

DO
PULSOUT 1, 100
PULSIN 1, 1, time
time = time ** 2251
DEBUG CR, "Distance = ", DEC4 time, " cm"
PAUSE 5
LOOP

Code 3:

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

DO
HIGH 1 ' start output "pulse" on P1
PULSIN 1, 1, W0 ' make P1 an input and measure return echo
W0=W0/72 ' convert to inches
DEBUG DEC W0,CR ' display data
PAUSE 50 ' delay stops ringing, reduces zeroes
LOOP

Code 4:

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

'*************************
' Pin connections

EchoPin CON 0 ' The pin that the terminal "echo" is connected to. Pin 0 is default.
TrigPin CON 1 ' The pin that the terminal "trig" is connected to. Pin 1 is default.

' Connect "GND" to ground / VSS
' Connect "VCC" or "5+" to positive / VCC

'*************************

' Don't edit below.
InConstant CON 890
inDistance VAR Word
time VAR Word

'*************************
' The code below gets measurements.

beginning: ' Simply used for "GOTO beginning"
DO ' Start of the loop.
PULSOUT TrigPin, 5 ' Send a 0.005 second pulse to Ping.
PULSIN EchoPin, 1, time ' Listens for the echo.

'*************************
' Coversion (Time to inches)

inDistance = inConstant ** time ' Convert time into inches. [inches = inConstant x time]

'*************************
' If statement.

IF ((inDistance = 0)) THEN DEBUG CR, "Not connected properly!": GOTO beginning: ENDIF ' If the distance is "0" then something isn't connected. And goto the beginning to remeasure.

'*************************
' Display management

DEBUG CR, DEC inDistance, "in" ' Display result in the debug terminal.
PAUSE 200 ' A 0.2 second delay until next measurement.

LOOP ' Start over.
'*************************

I have used the two Echo and Trig pins separately, and also joining them with a resistance of approximately 1.8K. And I would like to know if anyone has a solution for this.

Thank you.

Publison · 2020-01-29 17:04

Welcome to the forum!

Give the code in this thread a try. I do not own a HC-SR04 to try

https://forums.parallax.com/discussion/163555/ps2-hc-sr04-ultrasonic-sensor-code

You could also find this under the search funtions, (upper right of the page):

https://forums.parallax.com/search?Search=HC-SR04

Adolfo · 2020-02-12 13:21

Thank you very much for answering, but this code is the same as I had already tried, code 4

Adolfo · 2020-02-12 13:33

I have tried different codes to operate the HC-SR04 sensor and it only reads zeros, the board I am occupying is BASIC Stamp HomeWork Board USB and the codes that I have used are the following:

Code 1:

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

time VAR Word

main:

DO
LOW 9
PULSOUT 9, 20
PULSIN 8, 1, time
time = time ** 2251
DEBUG CR, "Distance = ", DEC4 time, " cm"
PAUSE 5
LOOP

Code 2:

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

time VAR Word

main:

DO
PULSOUT 1, 100
PULSIN 1, 1, time
time = time ** 2251
DEBUG CR, "Distance = ", DEC4 time, " cm"
PAUSE 5
LOOP

Code 3:

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

DO
HIGH 1 ' start output "pulse" on P1
PULSIN 1, 1, W0 ' make P1 an input and measure return echo
W0=W0/72 ' convert to inches
DEBUG DEC W0,CR ' display data
PAUSE 50 ' delay stops ringing, reduces zeroes
LOOP

Code 4:

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

'*************************
' Pin connections

EchoPin CON 0 ' The pin that the terminal "echo" is connected to. Pin 0 is default.
TrigPin CON 1 ' The pin that the terminal "trig" is connected to. Pin 1 is default.

' Connect "GND" to ground / VSS
' Connect "VCC" or "5+" to positive / VCC

'*************************

' Don't edit below.
InConstant CON 890
inDistance VAR Word
time VAR Word

'*************************
' The code below gets measurements.

beginning: ' Simply used for "GOTO beginning"
DO ' Start of the loop.
PULSOUT TrigPin, 5 ' Send a 0.005 second pulse to Ping.
PULSIN EchoPin, 1, time ' Listens for the echo.

'*************************
' Coversion (Time to inches)

inDistance = inConstant ** time ' Convert time into inches. [inches = inConstant x time]

'*************************
' If statement.

IF ((inDistance = 0)) THEN DEBUG CR, "Not connected properly!": GOTO beginning: ENDIF ' If the distance is "0" then something isn't connected. And goto the beginning to remeasure.

'*************************
' Display management

DEBUG CR, DEC inDistance, "in" ' Display result in the debug terminal.
PAUSE 200 ' A 0.2 second delay until next measurement.

LOOP ' Start over.
'*************************

I have used the two Echo and Trig pins separately, and also joining them with a resistance of approximately 1.8K. And I would like to know if anyone has a solution for this.

Thank you.

Duane Degn · 2020-02-12 14:25

Have you successfully used your HC-SR04 with any microcontroller?
Do you own more than one HC-SR04?
IIRC about 20% of the cheap HC-SR04 are dead on arrival.
I'm pretty sure I have a couple HC-SR04 sensors and a Basic Stamp board. I'll try to test this out today. (If no one else beats me to it.)

Duane Degn · 2020-02-13 20:56

Sorry but I haven't found my Basic Stamp board yet. I have found a few HC-SR04 sensors.
I'll keep looking.

Edit: I found it! Time to install Basic Stamp editor on this computer.

Capt. Quirk · 2020-02-14 00:14

Isn't there a problem with using "PulseOut" and "Pause" with the HC-SR04?

According to the data sheet pulseout isn't necessary because the HC-SR04
generates it's own signal after the trigger pin is held high for a min of 10us,
and pause is only capable of using 1ms increments.

Bill M.

Duane Degn · 2020-02-14 00:57

I just tried code 4 from above and it works with my hardware.

JerryHunter · 2024-05-13 15:04

I was puzzling with this for a few minutes just yesterday. Most of the time, the HC-SR04 would send zero values... but on rare occasions, I actually got legitimate values... then it hit me like a ton of bricks!

I was feeding power to the HC-SR04 from the power bus on my breadboard. Sure, it was 5v coming from a bench power supply, but... sometimes I could power the circuit on and it worked, and other times (most of the time) I powered the circuit on I got nothing but zeros. Reading the comments in this thread where they said there was a high failure rate on these sensors, I had almost decided to use a different method to solve my problem.

But just for grins and giggles, at the top of my code I flipped one of the spare pins of the BS2 HIGH and used THAT (regulated) pin as a source of power before I entered the loop to began sending the PULSOUT to the trigger and reading the PULSIN from the signal line. BOOM! Works every single time I power it up.

Sometimes the solution is the dumbest, most obvious thing I've simply overlooked.

SavageCircuits · 2024-05-13 16:02

@JerryHunter said:
But just for grins and giggles, at the top of my code I flipped one of the spare pins of the BS2 HIGH and used THAT (regulated) pin as a source of power before I entered the loop to began sending the PULSOUT to the trigger and reading the PULSIN from the signal line. BOOM! Works every single time I power it up.
Sometimes the solution is the dumbest, most obvious thing I've simply overlooked.

I wouldn't recommend powering the HC-SR04 from an I/O pin. It sounds to me like you quite possibly didn't have a common ground with the BASIC Stamp board. Whether you're powering the sensor from the BASIC Stamp board VCC or another source, there should be a common ground with the BASIC Stamp board.

HC-SR04 Ultrasonic Sensor

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