5/8 sensors HCsr04 from arduino to max for installation

From self-taught experience:
1. Getting data passing from Arduino to MAX through serial object is quite straightforward, once you have more or less understood the famous (and mysterious - at least for beginners) sequence of objects allowing to "decipher" the data received through the serial port and making it identical, in MAX, to the Arduino source message :

2. As far as sending each blablabla piece of data is concerned, the Arduino code should read as follows: Serial.print("blablabla");Serial.println(" ");

3. USB Arduino/Computer connections are reliable (but patches are long to load). Bluetooth is more chaotic. I am currently in the process of testing WIFI/OSC. Send regular "I-am-still-connected-type" messages from Arduino to MAX in order to detect connection losses easily.

4. As you will have several sensors, pay sufficient attention to the routing of data, otherwise you may end up with unmanageable situations in MAX !

5. You have plenty of tutorials explaining HCsr04 Arduino coding, which is pretty simple if you consider only basic usage. Just make sure you correctly set min/max and calibration of distances to avoid troubles.

6. Lastly, it may sound obvious, but it is more of a self-reminder, as I literaly hate doing that : for public performances/installations, the whole thing has to be very robust. Meticulous soldering of the different parts is a must. The use of simple jumper wires is definitely not enough (believe me ..).

Hello Sebastian thanks, yes indeed I had thought about the leaps of HCsr04, I will make a selection of incoming numbers. The problem I have now is that the USB serial doesn't work. I'm experimenting with the max test. Perhaps the USB serial is not good? I think I read that somewhere

Maybe.
Have you sent a print message to the serial object in order to have the connected items listed in the Max Console, and selected the letter corresponding to your Arduino ?
Are the Arduino and serial object baud rates identical ?

Yes Sebastien, here is the sketch and the patch

#define trigPin 6
#define echoPin 7
#define pinAlimenta 8

long durata, cm;

void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(pinAlimenta, OUTPUT);
digitalWrite(pinAlimenta, HIGH);
}
void loop()
{
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
durata = pulseIn(echoPin, HIGH);
cm = durata / 58; // per i pollici la formula è durata / 148;
Serial.write(cm);
}

Ok now work but if I quit from arduino IDE

using 2 apps at same time on same serial port does not work.
also to upload code, you need to send message close to serial in max.
Serial.write from arduino sends raw bytes 0 - 255,
using zl.group and itoa in max is not working for that.
-----
you could add a bit of delay in main loop in arduino,
and poll input faster in max.
that code could work for a single sensor, but for multiple
sensors you need either an ID prepended for each sensor,
or create array in arduino and send it as a list.
in any case using Serial.print and Serial.println.

depending on what infos you need from sensors,
one would prefer one or the other option.
if you need only to report if sensor has detected something
closer than nn cm, then it makes no sense to send a list of 8 sensors
all the time, but only state of each sensor if it changed.

As far as sending each blablabla piece of data is concerned, the Arduino code should read as follows: Serial.print("blablabla");Serial.println(" "); (1)

The sel 13 10 object "filters out" ASCII 13 and 10 values received through serial port and outputs the other values through its rightmost outlet. Indeed, Serial.println(" ") from Arduino is received as a pair of 13 (println = Carriage Return) and 10 (" " = Line Feed) out of the serial object. "blablabla" is coded by numbers always different from 13 or 10.

So each number corresponding to blablabla is consecutively placed in a list by the zl.group object (max size 1000), until a 13 is output by serial : at this moment, the list is forwarded to the itoa and fromsymbol objects to be "translated" into numbers or MAX message, and zl.group starts compiling a new list until the sel 13 10 object receives a 13, and so on.

(1). Alternatively, for numbers: Serial.print(number-to-be-sent);Serial.println(" ");

Hi Seba, I removed the Serial.write and inserted the other serial.print, but I only receive the data from the distance sensor, is that right?

#define trigPin 6

#define echoPin 7

long durata, cm;

void setup() {

Serial.begin(9600);

pinMode(trigPin, OUTPUT);

pinMode(echoPin, INPUT);

}

void loop()

{

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);

durata = pulseIn(echoPin, HIGH);

cm = durata / 58; // per i pollici la formula è durata / 148;

Serial.print("Cm = ");

Serial.println(cm);

Serial.println();

}