Can a 4-pin HC-SR04 ultrasonic sensor be used on the parallax board, i.e. with PropellerC?

dakotaknut

Can a 4-pin HC-SR04 ultrasonic sensor be used on the parallax board, i.e. with PropellerC?

I assume so.
Is there a tutorial or description.

I have an activitybot and have it working with the Parallax 3-pin sensor.
I had purchased two more sensors for use with an Arduino board I was going to try with some projects I have in mind.

I am working with my son on a maze solving robot and would like to connect three sensors.

Thanks for any help

dakotaknut

erco

dakotaknut:

Welcome to the forums! Yes, you can use those sensors with an Activity board. The PING is a much higher quality unit, but we've all been tempted by those $1 HC-SR04s. Like the PING shown at http://learn.parallax.com/activitybot/build-and-test-ping-sensor-circuit, you'll power it with 5V and use two resistors to interface to the 3.3V Propeller.

The four pin HC-SR04 has seperate TRIGger and ECHO pins, requiring two Prop I/O pins. BUT... there is a top secret, insider-exclusive, eyes-only, password-protected, secret-handshake-required, simple one-resistor modification to make it function on just one I/O pin. See this long-winded thread with lots of juicy info: http://forums.parallax.com/discussion/comment/1301893/#Comment_1301893

dakotaknut

OK, I found a sample that looks promising.
https://gist.github.com/flakas/3294829#file-hc-sr04-ino-L82

There are some build problems
Serial.begin doesn't work, but I don't think I need it

OUTPUT, LOW, and HIGH are all problems.
The example didn't show the header file I would need.
I am looking for examples of the use of these.
For example pinMode([pin], OUTOUT);
and digitalwrite([pin], LOW);

LOW and HIGH are undoubtedly as simple as 0 and 1.
I recollect seeing OUTPUT in an example sometime back when I was working on this a little bit.
I would like to use a header file for these. I assume that would be the best.

Thank you

dakotaknut

Hey, thank you, because my sample doesn't seem to be panning out like I was thinking it might.
I can't wait to take a look at this.

anxanywhere

Probably no one is still after this anymore, but I was able to use a 4-pin HC-SR04 with Propeller Activity Board (this was based on https://gist.github.com/flakas/3294829#file-hc-sr04-ino-L82 code)

#include "simpletools.h"

/* HC-SR04 Sensor
   https://www.dealextreme.com/p/hc-sr04-ultrasonic-sensor-distance-measuring-module-133696
  
   This sketch reads a HC-SR04 ultrasonic rangefinder and returns the
   distance to the closest object in range. To do this, it sends a pulse
   to the sensor to initiate a reading, then listens for a pulse 
   to return.  The length of the returning pulse is proportional to 
   the distance of the object from the sensor.
     
   The circuit:
	* VCC connection of the sensor attached to +5V
	* GND connection of the sensor attached to ground
	* TRIG connection of the sensor attached to digital pin 14
	* ECHO connection of the sensor attached to digital pin 15


   Original code for Ping))) example was created by David A. Mellis
   Adapted for HC-SR04 by Tautvidas Sipavicius

   This example code is in the public domain.
 */

const int trigPin = 14;
const int echoPin = 15;

int main()
{
  while(1)
  {
    // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
    // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
    low(trigPin);
    pulse_out(trigPin, 10);

    // Read the signal from the sensor: a HIGH pulse whose
    // duration is the time (in microseconds) from the sending
    // of the ping to the reception of its echo off of an object.
    long tEcho = pulse_in(echoPin, 1);

    // convert the time into a distance
    int inDist = tEcho / 148;
    int cmDist = tEcho / 58;

    print("%d inch\n", inDist);
    print("%d cm\n", cmDist);
  
    pause(200);
  }  
}

Publison

Welcome back after 4 years. All working code is most welcome. The HC-SR04 is pretty prevalent on ebay.