Hello, this is my first post on the forum.

I'm trying to create a high pass filter with Q using Biquad~.

As I don't have enough mathematical knowledge about filters and coefficients, I asked Chat GPT to help me understand the math, and I think I almost got it now.

The problem is that I'm executing everything it said me to, and I think the equations are correct, but it is not working properly, I get a kind of filter, but for sure it is not a high pass, and the Q always starts around 2000 Hz and I don't know why.

Can anybody please help me to understand what is going wrong?
I have some experience with Pd, but not with math or DSP.biquad_test_filter.pd

Ok, the cat is out of the bag --> https://github.com/porres/pd-else/releases/tag/1.0-rc13 I'm officialy announcing the update and uploaded binaries to deken for mac (intel/arm), Win and Linux. It all looks ok but tell me if you see something funny please. There's also a raspberry pi binary but not working 100%yet and we'll still look into that. Hopefully someone could help me/us with it. I might make another upload just for the pi later on if/when we figure it out. Find release notes and changelog below.

RELEASE NOTES:

Please support me on Patreon https://www.patreon.com/porres I'll now try to add special content for subscribers. You can follow me on instagram as well if you like... I'm always posting Pd development stuff over there https://www.instagram.com/alexandre.torres.porres/

It's been a little bit over 7 months since the last update and I almost broke the record for taking too long to release an update (which had happened in my previous update). So yeah, there's just too much to talk about! I guess the delays in releasing updates is because it's been a little tricky and hard to sync the release cycles of ELSE with PlugData, which includes ELSE in its download.

Plugdata 0.9.2 should come out soon with ELSE RC13 and it's supposedly the last update before 1.0.0, so I've heard. And the plans was to get to that still in 2025! This means ELSE could be at its last "Release Candidate" phase as I'm aiming to sync the final release with PlugData. Until then, I'll still make breaking changes and I can't wait until I can't do that anymore as I really feel bad. On the other hand, it's kind of inevitable when I'm always adding new stuff and redesigning and reconfiguring objects to include more functionalities. And I always got a lot of new stuff! So I'm thinking that I will eventually try some mechanism like Pd's compatibility flag or something. I'll try to come up with something like that in the next update.

This update has 22 new objects for a total of 573 and 26 new examples in my tutorial for a total of 554 examples. Let's dive into the highlights (see full changelog below after the release notes).

• Multichannel Support: Last release had 92 MC aware objects, now it's 139! Over a 50% increase that include old and new objects (all the new ones have been coming with MC support). Virtually all oscillators and envelope generators now have MC support, plus some other random ones. Let me highlight the new [lace~]/[delace~] objects that are 'MC' tools that perform interleave/deinterleave in Multichannel connections. My bare minimum number of objects "to start with" would be at least a bit over half the number of signal objects. That was my target for 1.0! ELSE right now has 319 signal objects, so that'd be at least 160. I will definitely pass this milestone in the next update. I guess a good number of MC objects would be around 75% of the signal objects. I will aim for that as soon as I can. Some objects simply can't be MC at all, so 100% will never be the case, but maybe an ideal 90% eventually? We'll see... I am just proud and happy that ELSE is taking such a big jump on MC awareness in less than a couple years.

• Envelope generators ([adsr~]/[asr~]/[envgen~]/[function~]) now have more curve options. For [adsr~]/[asr~] the default is now a new log curve that you can set the curve parameter (and was 'stolen' from SuperCollider). A new [smooth~] family of objects perform the same kind of curved smoothening for alternating inputs - [envgen~] and [function~] also have that but also '1-pole' filtering, 'sine' and 'hann' curves. You can now trigger [adsr~] and [asr~] with impulses.

• The [play.file~] object now supports even more file formats besides MP3 and stuff. Hey, you can even stream the supported formats from weblinks! The [sfload] object (which loads files into arrays) also gained support for more formats and can download from weblinks as well! It also has a new threaded mode, so loading big files won't choke Pd. It now also outputs the file information, which is a way to tell you when loading finished in threaded mode. The [sample~], [player~], [gran.player~] and [pvoc.player~] objects are now also based on [sfload], so they support all these file formats!!! Now [sample~] and [tabplayer~] are integrated in a way that [tabplayer~] is always aware of the sample rate of the file loaded in [sample~] (so it reads in the "correct speed"). A new [sfinfo] object is able to extract looping regions and instrument metadata information from AIFF files (which is something I wanted for ages) - it should do more stuff in the future.

• [knob] has become the ultimate featured bloated creep GUI I always feared and avoided. MAX is envy! but I'm happy with this structure and I want to replicate in other GUIs in the future (yeah, I got plans to offer alternatives to all iemguis). I wanna highlight a new 'param' symbol I added that allows you to remotely set a particular method in an object, so you don't to connect to a "method $1" message and you can even do this wirelessly with a send symbol. [knob] now also acts like a number box, where you can type in the value, which may also be displayed in different ways or the value can be sent elsewhere via another send symbol so you can temper with it using [makefilename] or [else/format]. I've been using this for the MERDA modules and it's really cool.

• We finally have a [popmenu] GUI object! This was in my to do list forever and was crucial to improve the MERDA modules to set waveforms, instruments and whatnot.

• Let's about MERDA, the "Modular Euroracks Dancing Along" subset of abstractions in ELSE. It was first released in the last update and it's been driving lots of the development in ELSE as you can see. I now added a MIDI Learn feature for all knobs that feels great and quite handy! There are many fixes and improvements in general and some new modules. I wanna highlight the new [sfont.m~] module, which loads "sound font" banks and you can just click on a [popmenu] to choose the instrument you want. The default bank has numerous (hundreds) options and also comes with PlugData. The sequencer module [seq8.m~] was rather worthless but it's now a whole new cool thingie. It allows you to set pitches with symbols and even has quarter tone resolution. I added a right outlet to send impulses to trigger envelopes and stuff (there's still more stuff of course, see full changelog below).

• There are newly designed/renamed/recreated [resonbank~]/[resonbank2~] objects that are well suited for Modal Synthesis.

• What actually drives my development is my Live Electronics tutorial, which got a fair upgrade with a new chapter on Modal Synthesis amongst other things, such as new subtractive synthesis examples and a revision of envelope generators with examples on AHDSR and DAHDSR - by the way, there are new gaterelease~/gatedelay~ objects for handling envelopes (and other processes).

• I have to thank some people. Tim added 'zoom' to the [pic] object, as well as an image offset. Tim also implemented a new and better technique for bandlimited oscillators. Ben Wesh gave me a new [scope3d~] GUI object, pretty cool, that plots an oscilloscope in 3 dimensions, which is coded in LUA - and ELSE has been carrying a modified version of [pdlua] because it now depends on it for a couple of GUIs. Tim and Ben made many improvements to [pdlua] (as well as Albert Graef, of course).

• For more new objects, let me also tell you about the simple and cool [float2imp~], that is based on [vline~] and can convert floats to impulses with sample accuracy (don't know why I didn't think of that earlier). A new [tanh~] object has Multichannel support. A bit earlier I made an update to Cyclone that actually "borrows" and includes this one from ELSE instead of its original one (which does not have Multichannel support). PlugData users will load the one from ELSE. This is another tiny step that sort of integrates ELSE and Cyclone, specially for PlugData users.

happy patching.

CHANGELOG:

LIBRARY:

Breaking changes:

• [adsr~]/[asr~]: now a gate off before reaching the sustain point does not start the release right away (this allows you to trigger it with impulses). There's a new mode just for immediate release. There's a new exponential setting for curve factors, the old 'log' mode is renamed to 'lag' as it's the same as used in the [lag~] object. For [adsr~], a bang now is not "retrigger", but an impulse at control rate, there's a new 'retrigger' message for control rate retriggering (and now it only retriggers if the gate is on). For [asr~] a bang now also works like an impulse.
• [sample~]: no more 'load' message, args to 'open' message changed, size is now only in 'ms'.
• [format]: outputs are now always symbols, before you could get float outputs. Also, we just have a simplified symbol output, no more lists or anythings. Hopefully I'll be able to get the 'list' output back, but it involved some bugs that I couldn't fix so I just removed it. You cannot use bangs and lists in secondary inlets no more (this is cylone/max crappy paradigm we don't want here). Bang method was actually removed as well.
• [pack2]: no more support for anythings, also no more support for lists in secondary inlets and output has a list selector (I wanna make this more Pd like and not a silly clone from MAX's [pak], cause fuck MAX).
• [merge]/[unmerge]/[group]: no more '-trim' flag (again, respecting pd's usual list paradigm), in [merge] now there's no more 'hot' argument and a bang now represents an empty list and inlets initialized with empty lists
• [mono]: 1st argument is now 'glide' in ms.
• [sfont~] now uses 'mma' for bank selection (this alters how CC messages set the bank number).
• [player~]/[play.file~]: 'open' message does not play files right away anymore.
• [tabplayer~]/[player~]: play message without args now play at the default settings (whole file at regular speed).
• [envgen~]: removed the 'maxsustain' parameter, use the new [gaterelease~] or [gaterelease] objects instead. Removed the rightmost inlet just to set envelopes, now a list input only sets the envelope and doesn't trigger it. The 'set' message is then removed.
• [envgen~]/[function~]: simplified and got rid of '-exp' flag and message, also deleted 'expl' and 'expi' messages. A new 'curve' and cimpler message sets exponential factors for all or individual segments, and includes more curve formats.
• [knob]: 'esc' key now deactivates the object. The 'ticks' message is renamed to 'steps' and there is a new 'ticks' message that toggles showing ticks on and off. The 'start' message has been renamed to 'arcstart'. The 'outline' message has been renamed to 'square' for better clarity. Design changed a bit to make it like it is in PlugData (they won), so we now fill the whole background color when in 'square mode' and the knob circle has an 85% proportion in this case inside the full 100% square size (so it grows bigger when not in 'square' mode). Now, by default, the GUI is in a new 'loadbang' mode (I don't think this will influence old patches). I'm afraid some old patches might behave really weird since I added a lot of new stuff. I changed the 'load' message behaviour to not update the object (this can arguably be considered a bug fix).
• [wavetable~], [bl.wavetable~] and [wt2d~]: 'set' message now sets frequencies because of the MC support in [wt~] and [wt2d~], while there's a new 'table' method to set the table name.
• [gbman~]/[cusp~] list method is now for MC, old list method is now renamed back to an old 'coeffs' method.
• [f2s~]/[float2sig~] default value is now 10 ms.
• [op] now behaves like [*~] where the smaller list wraps til reaching the size of the longer one.
• [list.seq] does not loop anymore by default.
• [impseq~] list input removed, use the new [float2imp~] object to convert floats to impulses.
• [resonant~] now has 'q' as the default.
• [resonant2~] has been removed.
• [decay2~] has also been removed ([asr~] much better).
• [vcf2~] has been renamed to [resonator2~].
• [resonbank~]/[resonbank2~] have basically been deleted and replaced by new objects with the same name... [resonator~] is based on a new [resonator~] object which is similar to [resonant~] and [resonbank2~] is now based on [resonator2~] (old [vcf2~] instead of [resonant2~] that got deleted). These are well suited objects for Modal Synthesis.
• [oscbank~] now uses a 'partial' list and not a frequency list. The freq input now defaults to '1' and this makes [oscbank2~] completely obsolete.
• [oscbank2~] has been deleted since it became completely obsolete.
• [sfload] load message changed the behaviour a bit.

Enhancements/fixes/other changes:

• [adsr~]: We have now a new mode for immediate release (see breaking changes above, I'm not repeating it). Fixed ADSR signal inputs (it was simply not really working, specially for linear). Fixed status output for MC signals. There's a new curve parameter that allows you to set the curvature.
• [asr~] I actually just made the new [adsr~] code into a new [asr~] code as a simplified version (as it was before)... so it's got the same impromevents/fixes.
• [play.file~]: added support for more file formats and even weblinks for online streaming!
• [sfload]: added an outlet to output information, added threaded mode, added support for more file formats and even weblinks for downloading.
• [sample~], [player~], [gran.player~] and [pvoc.player~] are now also based on [sfload], so they support more file formats!
• [sample~]: improved extension management with [file splitext].
• [sample~] and [tabplayer~] now are automatically integrated in a way that [tabplayer~] is always aware of the sample rate of the file loaded in [sample~], so it automatically adjusts the reading speed if it is different than the one Pd is running with.
• [numbox~]'s number display is not preceded by "~" anymore (that was just kinda stupid to have).
• [format]: fixed issues where empty symbols and symbols with escaped spaces didn't work. Added support '%a' and '%A' type. Added support for an escaped 'space' flag. Improved and added support for length modifiers. Improved syntax check which prevents a crash. Improved documentation.
• [knob]: added new 'param', 'var', 'savestate', 'read only', 'loadbang', "active", "reset" and 'ticks' methods. Added the possibility to type in number values and also modes on how to display these number values, plus new send symbols for 'activity', 'typing', 'tab' and 'enter'. New design more like plugdata. Changed some shortcuts to make it simpler. If you have the yet unreleased Pd 0.56-0 you can also use 'double clicking' in the same way that works in PlugData. Properties were also significantly improved (I'm finally starting to learn how to deal with this tcl/tk thingie). Yup, a lot of shit here...
• [autofade2~]/[autofade2.mc~]: fixed immediate jump up for 0 ramp up.
• [synth~]: fixed polyphony bug.
• [metronome~]: fixed bug with 'set' message.
• [midi2note]: fixed range (octaves 0-8).
• [pulsecount~]: fixed reset count to not output immediately, added bang to reset counter at control rate
• [click]: fixed regression bug where it stopped working.
• [else]: new 'dir' method to output ELSE's binary directory in a new rightmost outlet. The print information also includes the directory.
• [pic]: added zoom capability finally (thanks to tim schoen) and added offset message (also thanks to tim).
• [store]: added 'sort' functionality.
• [scales]: fixed octave number argument. Added functionality to allow octave number as part of the note symbol.
• [mono]: added 'glide' parameter, as in [mono~].
• [pluck~]: fixed list input.
• [rescale]/[rescale~]: added a "reverse log" mode.
• [limit]: added a new second ignore mode.
• [graph~]: added an external source input for plotting the graph and a 'clear' message.
• [canvas.setname]: added a new argument for "abstraction mode" and methods to set name, depth (and mode).
• [midi.learn]: added a new argument for "abstraction mode", fixed 'dirty' message sent to parent.
• [brickwall~]: fixed initialization.
• [list.seq]: added a loop mode and a 2nd outlet to send a bang when the sequence is done.
• [delete]: fixed index for positive numbers.
• [dust~]: added 'list', 'set' and '-mc' flag for managing the already existing Multichannel capabilities.
• Thanks to Tim we have many fixes and a whole new technique for band limited oscillators. Now [bl.saw~], [bl.saw2~], [bl.vsaw~], [bl.square~], [bl.tri~], [bl.imp~] and [bl.imp2~] have been redesigned to implement elliptic blep, which should provide better anti-aliasing.
• [parabolic~] now uses and internal wavetable for more efficiency.
• [resonant~]: added 'bw' resonance mode.
• [lowpass~]/[highpass~]: added 't60' resonance mode.
• [quantizer~]/[quantizer]: added a new mode, which combines floor (for negative) and ceil (for positive) values.
• [crusher~]: now uses the new [quantizer~] mode from above (arguably a breaking change).
• [envgen~]: fixed a bug (actually a misconception) where ramps started one sample earlier. Fixed 0-length lines. Added a possibility to set time in samples instead of ms. Maximum number of lines is now 1024. Added loop mode. Added many curve options (sin/hann/log curve/lag).
• [function~]: Added many curve options (sin/hann/log curve/lag).
• [The out~] family of abstractions now use [bitnormal~] so you won't blow your speakers beyond repair in edge cases.
• [trig.delay~]/[trig.delay2~]: fixed bug where impulse values different than '1' didn't work.
• Added MC support to: [trig.delay~], [trig.delay2~], [gatehold~], [vca.m~], [gain2~], [decay~], [asr~], [envgen~], [function~], [bl.osc~], [bl.saw~], [bl.saw2~], [bl.vsaw~], [bl.square~], [bl.tri~], [bl.imp~], [bl.imp2~], [imp2~], [tri~], [saw~], [saw2~], [vsaw~], [square~], [pulse~], [parabolic~], [gaussian~], [wavetable~], [wt2d~], [randpulse~], [randpulse2~], [stepnoise~], [rampnoise~] [pink~], [gbamn~], [cusp~], [gray~] and [white~].
• Also added MIDI input and soft sync to [imp2~], [tri~], [saw~], [saw2~], [vsaw~], [square~], [pulse~], [gaussian~] and [parabolic~].
• [wavetable~] and [wt2d~] gained args to set xfading.
• Updated pdlua to 0.12.23.
• M.E.R.D.A: Added MIDI-LEARN for all modules (this is only for the knobs). Replaced some number boxes that were attached to knobs by an internal number display mechanism (new feature from knob). Improved interface of [gendyn.m~]. Preset/symbol name fixes to [flanger.m~]. Now we have automatic MIDI mode detection for [plaits.m~] and [pluck.m~] when no signals are connected (still trying to get plaits right, huh? Yup! And bow MIDI input with monophony and trigger mode has been fixed in [plaits.m~]). Added MC support to [vca.m~]. Increased range of [drive.m~] down to 0.1. Changed some objects to include the new [popmenu] GUI. [vco.m~] now uses the new MC functionalities of oscillators and doesn't need to load abstractions into [clone], I hope it makes this more efficient and clean. The [seq8.m~] module was worthless and got a decent upgrade, it's practically a new module. Added new modules (see below). Note that MERDA is still at alpha development phase, much experimental. Expect changes as it evolves.
• 22 new objects: [float2imp~], [lace], [delace], [lace~], [delace~], [gatehold], [gatedelay],[gatedelay~], [gaterelease~], [gaterelease], [popmenu], [scope3d~], [tanh~], [resonator~], [sfinfo], [smooth], [smooth2], [smooth~], [smooth2~], [dbgain~], [level~] plus [crusher.m~], [sfont.m~] and [level.m~] MERDA Modules.

Objects count: total of 573 (319 signal objects [139 of which are MC aware] and 254 control objects)!

• 323 coded objects (210 signal objects / 113 control objects)
• 227 abstractions objects (87 signal objects / 140 control objects)
• 23 MERDA modular abstractions (22 audio / 1 control)

TUTORIAL:

• New examples and revisions to add the new objects, features and breaking changes in ELSE.
• Added the MERDA modules into the examples for reference.
• Revised section on envelopes.
• New subtractive synthesis examples.
• New chapter on Modal Synthesis.
• Total number of examples is now 554! (26 new ones)

@oid said:

@inari said:

However what's not clear is how these different sample rates get into the filter blocks, which use x_sr for calculating their coefficients.

But they also use c_coef and c_x which take current sample rate into account because they are type _samplerate. From d_ugen.c:

/* ------------------------ samplerate~~ -------------------------- */

static t_class *samplerate_tilde_class;

typedef struct _samplerate
{
    t_object x_obj;
    t_float x_sr;
    t_canvas *x_canvas;
} t_samplerate;

static void samplerate_tilde_bang(t_samplerate *x)
{
    outlet_float(x->x_obj.ob_outlet, canvas_getsr(x->x_canvas));
}

static void *samplerate_tilde_new(void)
{
    t_samplerate *x = (t_samplerate *)pd_new(samplerate_tilde_class);
    outlet_new(&x->x_obj, &s_float);
    x->x_canvas = canvas_getcurrent();
    return (x);
}

static void samplerate_tilde_setup(void)
{
    samplerate_tilde_class = class_new(gensym("samplerate~"),
        (t_newmethod)samplerate_tilde_new, 0, sizeof(t_samplerate), 0, 0);
    class_addbang(samplerate_tilde_class, samplerate_tilde_bang);
}

/* -------------------- setup routine -------------------------- */

void d_ugen_setup(void)
{
    block_tilde_setup();
    samplerate_tilde_setup();
}

I think if you do the math it will work out but I could be missing something, OOP in C plus heavy pointer use plus math symbols thrown about with pointer symbols always leaves me a but unsure of what is going on if not completely lost.

The use of globals across multiple files in the PD source as well as the breaking of OOP principles by calling member functions of blocks that aren't used (looking at you osc~, vcf~ and cos~) amounts to a crime against humanity... A shame really. If you don't look at how the sausage is made, PD is a nifty little language, but the moment something breaks or needs to be extended, watch out...

@inari said:

However what's not clear is how these different sample rates get into the filter blocks, which use x_sr for calculating their coefficients.

But they also use c_coef and c_x which take current sample rate into account because they are type _samplerate. From d_ugen.c:

/* ------------------------ samplerate~~ -------------------------- */

static t_class *samplerate_tilde_class;

typedef struct _samplerate
{
    t_object x_obj;
    t_float x_sr;
    t_canvas *x_canvas;
} t_samplerate;

static void samplerate_tilde_bang(t_samplerate *x)
{
    outlet_float(x->x_obj.ob_outlet, canvas_getsr(x->x_canvas));
}

static void *samplerate_tilde_new(void)
{
    t_samplerate *x = (t_samplerate *)pd_new(samplerate_tilde_class);
    outlet_new(&x->x_obj, &s_float);
    x->x_canvas = canvas_getcurrent();
    return (x);
}

static void samplerate_tilde_setup(void)
{
    samplerate_tilde_class = class_new(gensym("samplerate~"),
        (t_newmethod)samplerate_tilde_new, 0, sizeof(t_samplerate), 0, 0);
    class_addbang(samplerate_tilde_class, samplerate_tilde_bang);
}

/* -------------------- setup routine -------------------------- */

void d_ugen_setup(void)
{
    block_tilde_setup();
    samplerate_tilde_setup();
}

I think if you do the math it will work out but I could be missing something, OOP in C plus heavy pointer use plus math symbols thrown about with pointer symbols always leaves me a but unsure of what is going on if not completely lost.

@Luizagimenez said:

I have a work assigned to translate some Graphs from UV lightning on molecules to an array in Pure Data. Im trying to find a way to get the Quadratic Equations that have complex numbers to show on a somewhat precise array or graph, so i can use these numbers for frequencies, to create a movable bar to select a pixel of the graphic.

Pd can express any math formula, but it's more cumbersome for complicated math expressions than a text-based language. [expr] helps somewhat, though. A real-number (no complex) quadratic would look like this:

If a quadratic is ax2 + bx + c, and you need complex numbers, is it that a, b and c can be complex, or only x? Your graph suggests a real-number domain, in which case complex a, b, c would be the sum of 2 quadratics, one multiplied by i. So, the above patch, but duplicated, to give you a real and an imaginary result.

If x can be complex too, then it's more involved than that.

hjh

you could make a simple abstraction that just outputs a certain number when banged:
multi-math.zip

The ultrasonic distance sensors are usually digital, not analog. If this is the case, you're trying to read a digital signal as analog, which doesn't make much sense. This sensor has two pins, a trigger and an echo. You have to send a high voltage to the trigger pin, then pull it low, and read the echo pin which will help you compute the distance based on the time it took for this trigger pulse to arrive back at the echo pin.
The code below (copied from Arduino'g Project Hub), uses Arduino's pulseIn() function, to compute the distance:

// Define Trig and Echo pin:
#define trigPin 2
#define echoPin 3
//  Define variables:
long duration;
int distance;
void setup() {
  // Define  inputs and outputs:
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  //Begin Serial communication at a baudrate of 9600:
  Serial.begin(9600);
}
void  loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  digitalWrite(trigPin,  HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Read  the echoPin, pulseIn() returns the duration (length of the pulse) in microseconds:
  duration = pulseIn(echoPin, HIGH);
  // Calculate the distance:
  distance=  duration*0.034/2;
  // Print the distance on the Serial Monitor
  Serial.print("Distance  = ");
  Serial.print(distance);
  Serial.println(" cm");
  delay(1000);
}

I searched online and found the source of this pulseIn() function in Arduino's forum, which is this:

/*
  wiring_pulse.c - pulseIn() function
  Part of Arduino - http://www.arduino.cc/

  Copyright (c) 2005-2006 David A. Mellis

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA

  $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
*/

#include "wiring_private.h"
#include "pins_arduino.h"

/* Measures the length (in microseconds) of a pulse on the pin; state is HIGH
 * or LOW, the type of pulse to measure.  Works on pulses from 2-3 microseconds
 * to 3 minutes in length, but must be called at least a few dozen microseconds
 * before the start of the pulse. */
unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout)
{
    // cache the port and bit of the pin in order to speed up the
    // pulse width measuring loop and achieve finer resolution.  calling
    // digitalRead() instead yields much coarser resolution.
    uint8_t bit = digitalPinToBitMask(pin);
    uint8_t port = digitalPinToPort(pin);
    uint8_t stateMask = (state ? bit : 0);
    unsigned long width = 0; // keep initialization out of time critical area
    
    // convert the timeout from microseconds to a number of times through
    // the initial loop; it takes 16 clock cycles per iteration.
    unsigned long numloops = 0;
    unsigned long maxloops = microsecondsToClockCycles(timeout) / 16;
    
    // wait for any previous pulse to end
    while ((*portInputRegister(port) & bit) == stateMask)
        if (numloops++ == maxloops)
            return 0;
    
    // wait for the pulse to start
    while ((*portInputRegister(port) & bit) != stateMask)
        if (numloops++ == maxloops)
            return 0;
    
    // wait for the pulse to stop
    while ((*portInputRegister(port) & bit) == stateMask) {
        if (numloops++ == maxloops)
            return 0;
        width++;
    }

    // convert the reading to microseconds. The loop has been determined
    // to be 20 clock cycles long and have about 16 clocks between the edge
    // and the start of the loop. There will be some error introduced by
    // the interrupt handlers.
    return clockCyclesToMicroseconds(width * 21 + 16); 
}

This is already getting complicated, as pulseIn() uses other functions which should be found and translated to Pd. I guess the best thing you can do is try to translate the first code chuck in this reply to Pd, and when you read a high voltage in the echo pin, do some math to calculate the distance.
In essence, set a digital input and a digital output pin on the Bela, trigger the output pin with a high and low signal, and keep reading the input pin (you should probably use a pull-down resistor there), until you get a high. Calculate the time it took with the [timer] object and do some simple math to get the distance. Do that with distances you know first, and then use the rule of three based on the known distance and the time you get. At least, that's how I would try to get this to work.

Another solution is to use an infrared proximity sensor, which is analog, and it's probably much easier to use. But this gets the proximity of obstacles right in front of it only, while the ultrasonic range finder has a wider field where it can detect obstacles.

@alexandros

thanks for the suggestion! I"ve never compiled anything before, but I gave it a shot...

I'm getting this error in PD after loading the 3 compiled objects (6 files: grambidec.pd_darwin, grambidec.pd_darwin.o, grambiman.pd_darwin, grambiman.pd_darwin.o, grambipan.pd_darwin, grambipan.pd_darwin.o):

 load_object: Symbol "grambiman_setup" not found in "/Users/brianlindgren/Documents/Pd/externals/grambiman.pd_darwin"

Also make is generating a bunch of warnings:

++++ info: using Makefile.pdlibbuilder version 0.7.0
++++ info: using Pd API /Applications/Pd-0.54-1.app/Contents/Resources/src/m_pd.h
++++ info: making target all in lib grambidec~
++++ info: making grambidec.pd_darwin.o in lib grambidec~
cc -DPD -I "/Applications/Pd-0.54-1.app/Contents/Resources/src"  -DUNIX -DMACOSX -I /sw/include    -Wall -Wextra -Wshadow -Winline -Wstrict-aliasing -O3 -ffast-math -funroll-loops -fomit-frame-pointer -arch arm64 -mmacosx-version-min=10.6 -o grambidec.pd_darwin.o -c grambidec.c
grambidec.c:41:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:43:16: warning: unused variable 'APin2' [-Wunused-variable]
    t_sample  *APin2 =    (t_sample *)(w[3]);
               ^
grambidec.c:44:16: warning: unused variable 'APin3' [-Wunused-variable]
    t_sample  *APin3 =    (t_sample *)(w[4]);
               ^
grambidec.c:45:16: warning: unused variable 'APin4' [-Wunused-variable]
    t_sample  *APin4 =    (t_sample *)(w[5]);
               ^
grambidec.c:69:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:78:23: warning: variable 'sample2' set but not used [-Wunused-but-set-variable]
    t_sample sample1, sample2, sample3, sample4;
                      ^
grambidec.c:78:41: warning: variable 'sample4' set but not used [-Wunused-but-set-variable]
    t_sample sample1, sample2, sample3, sample4;
                                        ^
grambidec.c:102:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:113:41: warning: variable 'sample4' set but not used [-Wunused-but-set-variable]
    t_sample sample1, sample2, sample3, sample4;
                                        ^
grambidec.c:143:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:185:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:228:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:282:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambidec_tilde *x = (t_grambidec_tilde *)(w[1]);
                       ^
grambidec.c:351:37: warning: unused parameter 's' [-Wunused-parameter]
void *grambidec_tilde_new(t_symbol *s, int argc, t_atom *argv) //, t_floatarg test
                                    ^
grambidec.c:473:5: warning: performing pointer subtraction with a null pointer has undefined behavior [-Wnull-pointer-subtraction]
    CLASS_MAINSIGNALIN(grambidec_tilde_class, t_grambidec_tilde, APf);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Pd-0.54-1.app/Contents/Resources/src/m_pd.h:529:59: note: expanded from macro 'CLASS_MAINSIGNALIN'
    class_domainsignalin(c, (char *)(&((type *)0)->field) - (char *)0)
                                                          ^ ~~~~~~~~~
15 warnings generated.
++++ info: linking objects in grambidec.pd_darwin for lib grambidec~
cc -undefined suppress -flat_namespace -bundle  -arch arm64 -mmacosx-version-min=10.6  -o grambidec.pd_darwin grambidec.pd_darwin.o  -lc   
ld: warning: -undefined suppress is deprecated
ld: warning: -undefined suppress is deprecated
++++ info: making grambiman.pd_darwin.o in lib grambidec~
cc -DPD -I "/Applications/Pd-0.54-1.app/Contents/Resources/src"  -DUNIX -DMACOSX -I /sw/include    -Wall -Wextra -Wshadow -Winline -Wstrict-aliasing -O3 -ffast-math -funroll-loops -fomit-frame-pointer -arch arm64 -mmacosx-version-min=10.6 -o grambiman.pd_darwin.o -c grambiman.c
grambiman.c:64:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambiman_tilde *x = (t_grambiman_tilde *)(w[1]);
                       ^
grambiman.c:139:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambiman_tilde *x = (t_grambiman_tilde *)(w[1]);
                       ^
grambiman.c:226:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambiman_tilde *x = (t_grambiman_tilde *)(w[1]);
                       ^
grambiman.c:252:32: warning: variable 'sample3' set but not used [-Wunused-but-set-variable]
    t_sample sample1, sample2, sample3, sample4, sample10;
                               ^
grambiman.c:306:24: warning: unused variable 'x' [-Wunused-variable]
    t_grambiman_tilde *x = (t_grambiman_tilde *)(w[1]);
                       ^
grambiman.c:370:37: warning: unused parameter 's' [-Wunused-parameter]
void *grambiman_tilde_new(t_symbol *s, int argc, t_atom *argv)
                                    ^
grambiman.c:436:5: warning: performing pointer subtraction with a null pointer has undefined behavior [-Wnull-pointer-subtraction]
    CLASS_MAINSIGNALIN(grambiman_tilde_class, t_grambiman_tilde, APf);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Pd-0.54-1.app/Contents/Resources/src/m_pd.h:529:59: note: expanded from macro 'CLASS_MAINSIGNALIN'
    class_domainsignalin(c, (char *)(&((type *)0)->field) - (char *)0)
                                                          ^ ~~~~~~~~~
7 warnings generated.
++++ info: linking objects in grambiman.pd_darwin for lib grambidec~
cc -undefined suppress -flat_namespace -bundle  -arch arm64 -mmacosx-version-min=10.6  -o grambiman.pd_darwin grambiman.pd_darwin.o  -lc   
ld: warning: -undefined suppress is deprecated
ld: warning: -undefined suppress is deprecated
++++ info: making grambipan.pd_darwin.o in lib grambidec~
cc -DPD -I "/Applications/Pd-0.54-1.app/Contents/Resources/src"  -DUNIX -DMACOSX -I /sw/include    -Wall -Wextra -Wshadow -Winline -Wstrict-aliasing -O3 -ffast-math -funroll-loops -fomit-frame-pointer -arch arm64 -mmacosx-version-min=10.6 -o grambipan.pd_darwin.o -c grambipan.c
grambipan.c:423:5: warning: performing pointer subtraction with a null pointer has undefined behavior [-Wnull-pointer-subtraction]
    CLASS_MAINSIGNALIN(grambipan_tilde_class, t_grambipan_tilde, APf);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Pd-0.54-1.app/Contents/Resources/src/m_pd.h:529:59: note: expanded from macro 'CLASS_MAINSIGNALIN'
    class_domainsignalin(c, (char *)(&((type *)0)->field) - (char *)0)
                                                          ^ ~~~~~~~~~
1 warning generated.
++++ info: linking objects in grambipan.pd_darwin for lib grambidec~
cc -undefined suppress -flat_namespace -bundle  -arch arm64 -mmacosx-version-min=10.6  -o grambipan.pd_darwin grambipan.pd_darwin.o  -lc   
ld: warning: -undefined suppress is deprecated
ld: warning: -undefined suppress is deprecated
++++info: target all in lib grambidec~ completed

This is my Makefile:

# Makefile for mylib

lib.name = grambidec~

class.sources = grambidec.c grambiman.c grambipan.c

datafiles = grambilib-help.pd readme.md

include Makefile.pdlibbuilder

Any suggestion? Thanks again!

Hi all - I'm trying to compile PD for my M1 Mac and I have not been able to figure out how to get this to work. It keeps ending up with an Intel based app even though when I run configure it appears to be set up correctly. Configure gives this output:

pd 0.54.0 is now configured

Platform:             Mac OSX
Float size:           default
Debug build:          no
Universal build:      no
Localizations:        yes
Source directory:     .
Installation prefix:  /usr/local

Compiler:             gcc
CPPFLAGS:             -DNDEBUG  
CFLAGS:               -mmacosx-version-min=10.6 -ffast-math -fno-finite-math-only -funroll-loops -fomit-frame-pointer -O3  -g -O2
LDFLAGS:              -L/usr/local/lib  
INCLUDES:             -I/usr/local/include 
LIBS:                 

External extension:   d_fat
External CFLAGS:      -fPIC
External LDFLAGS:     -bundle -undefined dynamic_lookup
Deken identifier:     darwin-arm64

fftw:                 no
wish(tcl/tk):         default search paths
watchdog:             yes
audio APIs:           PortAudio 
midi APIs:            PortMidi 

However, when I subsequently run 'make' and then 'make app' the app it generates is an Intel app. I can tell by looking at the app with 'get info' in Finder, or by looking at it in Activity Monitor when it is running and seeing that it is an Intel process. Can somebody please help me make this natively for Mac architecture?

(FYI, I am doing a custom compile because I need to extend the MIDI FIFO size to avoid overflow for my specific use case)

Thanks!

@esaruoho Like this?
slowarray.pd

The time and frequency arrays output floats in the range of 0-1 which are shifted to the desired range, for time it is 1-60 minutes by the [*1000]->[*60] and for frequency it is 8.5hz-17hz, [*8.5] to shift the 0-1 output of line to span 8.5 hz and [+8.5] to get it to run from 8.5hz up to 17hz.

Edit, error in the math for the time, should be {* 1000]->[* 60]->[* 60], first converts 0-1 to ms, second converts to seconds, third does minutes. lost a [* 60] somehow. Or you can just [* 3e+06] instead but I like to keep the math easy to read. Fixed the file but not the image.