Arduino Due : Impossible to use the fonctiobn pulsein()

Hello,

I want to run an ultrasonic sensor HC-SR04 with an Arduino Due with simulink

I program my s-function

Outputs:

digitalWrite(6, HIGH);
delayMicroseconds(10);
digitalWrite(6, LOW);
Distance[0] = pulseIn(7, HIGH)/58;

I pass all the details off the code. I have tried lot of thing on the code and with another sensor (grove ultrasonic sensor). I had a look with an oscilloscope too..

I know my code is good but my problem is that pulsein() never send me a good value.

I run succefully a code working with interuption but I want to know why the function pulsein() is not working

I run Matlab R2017A

Is someone add the same problems too? and is someone have a solution?

Thank you

[Anton Soppelsa]

Hello,

I have the same problem with Simulink and Arduino uno. I developed the drivers to read the ultrasonic sensor as a System Class.

I think there is more than one problem with the build of pulseIn() function using the RTW.

1) Problems with the wiring_pulse.S file:

1.a) It doesn't get compiled, therefore the linker issues the "undefined symbol" error for the function countPulseASM

1.b) If i copy it locally in my driver source directory, still there are problems of object name classes and it get cancelled at every build

1.c) If rename the file to wiring_pulse_asm.S in my local dir still I don'T know how to add the file as source (adding in the system class does not seem to work)

1.d) If I use the C source code from which the assembly file has been derived I can compile and run, but in the end the system does not work because the pulseIn functions always timeouts.

2) Also pulseInLong (not relying on the assembly function) always timeouts

3) In Simulink, it seems that my class is not constructed correctly when in the init callback i perform a new Class(parameters). Parameter come from the mask of the block.

Note that I am using the same class in the Arduino IDE and things there work perfectly

Unfortunately I have no solution for this at the moment.

Sincerely,

[Girard Thomas]

I didn't see your answer before but for sure pulsein wasn't working for me and I resolve the problem using interupt fonction to measure the time between the 2 state of the input (in order to remplace pulsein() function)

[Rabia Samad]

how did you use the interrupt function? can you share your code

[omar Elkawokgy]

I have came up with a work around to ignore the assebly "wiring_pulse.S". I used the C function present in the comment of the file itself ("wiring_pulse.S") as shown below:

/*
 * The following routine was generated by avr-gcc 4.8.3 with the following parameters
 * -gstabs -Wa,-ahlmsd=output.lst -dp -fverbose-asm -O2
 * on the original C function
 *
 * unsigned long pulseInSimpl(volatile uint8_t *port, uint8_t bit, uint8_t stateMask, unsigned long maxloops)
 * {
 *     unsigned long width = 0;
 *     // wait for any previous pulse to end
 *     while ((*port & bit) == stateMask)
 *         if (--maxloops == 0)
 *             return 0;
 *
 *     // wait for the pulse to start
 *     while ((*port & bit) != stateMask)
 *         if (--maxloops == 0)
 *             return 0;
 *
 *     // wait for the pulse to stop
 *     while ((*port & bit) == stateMask) {
 *         if (++width == maxloops)
 *             return 0;
 *     }
 *     return width;
 * }
 *
 * some compiler outputs were removed but the rest of the code is untouched
 */

I added the function above in "wiring_pulse.c" after uncommenting it, also added its prototype in "wiring_private.h". I build and flashed without building or linking errors.

I have attached the files with changes surrounded with tag " /*OELKAWOK*/ "

Note: I have not verified this on a sensor yet, so I do not know if this function will get the correct data from the sensor or not