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1
having a bit of trouble finding an lm338, I am getting most of the components from old boards, what kind of electronics might i find one in?

also found some other chips that may be applicable:

k2611-n channel mosfet
70l02gp - n channel mosfet
uc3845, uc3843 -currentMode pwm controlers
lm339-quad comparator

im done for the night, will check back in tommorow
2
True with a gear train, but no with a worm and gear. Just friction. Weight will increase the friction, but will not change based on direction if the worm/gear are properly designed. That is why they are so efficient.

Paul
I was taught that a worm drive is the equivalent of pushing an object up or down an incline plane, as a screw thread is involved..
If the load torque was always against the direction of worm drive direction, then torque will be the same.
BUT
The load torque is in one case against the worm drive direction in the windup case, and with the worm drive direction in the wind down case.

Why do you need torque control on unwinding?
As the cable tension will be less, I would be more worried about speed?

The maximum torque is when you are winding up.
No motor torque when stationary, but cable drum torque still present.
Lower motor torque on winding down.


Tom... :)
3
confused ? you bet !    'transliteration ? "  yeah, had to stop and look that one up.

I  would start with the premise that any physical contact devices can be damaged.
also physical devices can fail from use or poor manufacturing.

also, like the beam/break,  any single point detector misses 99.99% of the rest of the space.

look at your refrigerator door.  or car door. it has a switch that senses when the door is open or closed.
simple button.   very easy to put 100 or so into one Arduino with some supporting chips.

car park is often a metalic object detector.  the presence of the metal object being a car.
this too could work

a simple ceiling mounted IR   beam/break could work.  item placed might break the beam or reflect it.   could be problematic

also a ceiling mounted ultrasonic distance detector. 

some from of load cell could be used to monitor the weight of the shelf.   as long at the items have enough weight, it might work.  more expensive and more electronics and more elaborate, but more informative.

a 'barn door'  The floor could be hinged in the front and be sprung in the back.  weight on the shelf has it sitting on the stops, but pressed the switch when it has weight.  not a load cell, but anything that weighs enough would activate the switch.

you did not say if this was a school project and if there are other requirements.




4
Code: [Select]
* this program works as advertised
But that isn't the code you are asking questions about. So, why would you post that code?
5
Programming Questions / Re: i dont know how to use a ...
Last post by PaulS - Today at 11:03 am
Code: [Select]
           if(tecla)
            {
              numero[indice]=tecla;
              indice++;
              posX++;
              lcd.setCursor(posX, 1);
              lcd.print(tecla);       
            }   

Even if the user has pressed 23 different keys, keep writing beyond the end of the array...

You REALLY need to make sure that there is room in the array BEFORE you write to it.

Quote
with * a number that you enter is deleted.
Code: [Select]
     case '*':                     //La tecla B sirve para borrar el caracter anterior escrito
     
        lcd.setCursor(0, 1);
        lcd.clear();
        break;

Just erasing what was on the LCD is nowhere near enough. Remember the array you are storing data in? That needs to be cleared, too. Remember the index into that array? That needs to be reset to 0, too.

Code: [Select]
      case '#':                     //La tecla C borra TODO lo escrito en la pantalla y posiciona el cursor en (0,0)
       
        EEPROM.write(eepromcaja1,indice);// Escribimos en la memoria eeprom
        menu=0;
        lcd.clear();
     
        break;

Storing the array index in EEPROM seems like a dumb thing to do. Storing the data in the array seems more useful. YMMV.

6
Français / Re: asm bug du compilateur?
Last post by ChristopheFr - Today at 11:03 am
T2 est le temps écoulé depuis l'initialisation du timer donc le cumul des deux passages delay4cycles:
Code: [Select]

TCNT1 = 0; // initialiser le compteur à 0
delay4cycles(10);
t1 = TCNT1; // lire le compteur
delay4cycles(11);
t2 = TCNT1; // relire le compteur
7
Hello geeks,

Can you help me to program a motor shield with three LEDs and a push button, and limit sensor.

Actions:

- after pressing the push button, start the engine (clockwise);
(during this action an LED flashes).

-The motor stops when the end of travel sensor detects the end of position, the LED stops flashing.

-When a new press the motor works in the other direction (counter-clockwise), and the other limit switch does the same (stops the motor); The same LED flashes, and also stops when the sensor detects.
8
I thought firstly sending byte data seperated by comma then, on server, I could make string data to image byte .

targetUrl is http://camerauploading.herokuapp.com/pic and work find with postman test(sending sth with post)

Node js server is as below
and for postman post Test. it comes to pic come logs and request method is logged as POST .
but once I request post. I didn't reach here and httpCode result is -1 . not 200

 app.post('/pic',function(request,response){
   console.log("pic come");
  console.log(request.method);
   if (request.method === 'POST') {

   }
  }
9
Hello,

I would be very grateful if someone could help me.
I have an ARDUINO MEGA 25600 + RDM6300 + LCD display connected.

How can I achieve that time when RFID is read, is displayed on the LCD screen??




10
Deutsch / Re: Info: Preview ESP32 (Nachf...
Last post by Tommy56 - Today at 10:58 am
Naja Preview und neu ist wohl etwas übertrieben.

Gruß Tommy
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