That’s why I designed a quick connector in CAD that makes it very easy to solder jumper cables. The connector serves as an ideal soldering aid. Of course, the wire diameter must be sufficient for the required number of amperes! On the market there are mainly inferior connectors. My STL file on the other hand is cheap and works perfectly.

This might also be interesting: Universal connector housing!

List of components

• 4 Pin RGB LED Strip
• Jumper cable
• Heat shrink tubing
• Hot Glue

Project application

For a larger project I needed 16 RGB strips with 21 LEDs each. The strips were pushed into a 3D printed socket afterwards. The LED strip was separated directly at the pre-marked point with a standard pair of scissors (usually the RGB strips are divisible after every third LED).

For the jumper cables I chose one side male and the other female. The side with the PINs (male) were soldered to the RGB strip and the socket (female) was used as a plug. It is crucial to use jumper cables with square housing (standard dimension: 2.54 mm). The length of the plastic housing does not matter. Depending on the brand, the plastic housings are 12 mm or 14 mm long.

Procedure

Since no preparatory work on the cables is necessary, soldering can be started directly. I prefer to apply solder to the RGB strip at the soldering points (copper layer) first.  After that I solder the PINs to the soldering points without additional solder. The PINs should not be soldered too deep towards the LED and the alignment must fit.

Then the connector comes into play. This connector is on the RGB side and open at the top. The RGB strip is inserted into the connector so that the solder joints are in the connector. Then the four cables are pressed into the slots and the solder joints are sealed with hot glue if necessary. For safety reasons, I recommend to attach a heat shrink tubing. This way you get a super strong connection!

Steps in pictures

Advantages:

• No cable preparation
• Strong connection
• Easy 3D printing

Disadvantages:

• Requires more space
• STL file only for RGB strips with 10 mm width

Download files

• • STL file of the soldering aid

The post Printed connector as soldering aid for jumper cables and LED strips appeared first on Nerd Corner.

This might also be interesting for you: Simple guide on how to use a Hall Sensor with an Arduino

List of components

• Arduino Nano
• Nano Terminal Adapter
• 6 magnets
• Hall sensor KY024
• LED strip
• Jumper cables
• Screws 2x M2 and 1x M3 for the sensor
• Deep groove ball bearing 6807 2RS / 61807 2RS 35x47x7 mm
• 3D printing test setup (STL files in Download section)

Construction of test bench

First we glued the 6 magnets into the 3D printed wheel. Make sure that the magnets are aligned homogeneously. Then the deep groove ball bearing is inserted into the detection wheel. The wheel can now be connected to the 3D printed bracket. Next we attach the Hall sensor KY-024 to the bracket. The Arduino Nano is plugged onto the adapter terminal and also attached to the bracket. The LED strip does not have to be attached separately. So you can start with the wiring.

Wiring

The wiring is not very difficult. Proceed according to the fritzing sketch. Connect the 4 jumper cables to the pins of the Hall sensor KY-024 and connect them to the Arduino Terminal Adapter. The 5V output of the Arduino is shared with both the Hall Sensor and the LEDs. Since there are only a few LEDs, no external power supply is required. For the LED strip you may have to solder them. We recommend to use a 220 Ohm resistor for the digital input of the LED strip.

Arduino Code Simple (with digital input)

In this code example, the Hall sensor KY024 sends the digital value 1 (HIGH) if there is a magnet or 0 (LOW) if no magnet is nearby. As soon as a HIGH is detected, the LEDs start to light up. But if the a magnet stops in front of the Hall sensor, it will send a HIGH constantly and the LEDs won’t stop lightning.

#include <FastLED.h>
#define LED_PIN     7
#define NUM_LEDS    6

CRGB leds[NUM_LEDS];

int digitalPin = 9; // Hall magnetic sensor input 1 (high) or 0 (low)
int digitalInputValue ; // digital readings

void setup ()
{
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  pinMode (digitalPin, INPUT); 
  
  Serial.begin(9600);
}

void loop ()
{
  
  digitalInputValue = digitalRead(digitalPin) ; 
  Serial.println(digitalInputValue); // print value
  if (digitalInputValue == HIGH) 
  {
    for (int i = 0; i <= 5; i++) 
    {
    leds[i] = CRGB ( 255, 0, 0);
    FastLED.show();
    delay(40);
    }
  }

  else if (digitalInputValue ==LOW)
  {
    for (int i = 0; i <= 5; i++) 
    {
      leds[i] = CRGB ( 0, 0, 0);
      FastLED.show();
      delay(30);
    }
  } 
}

Arduino code more advanced (with analog input)

This code is a bit more advanced. The goal for the Hall Sensor Movement Detection is to let the LEDs light up as soon as a rotary movement is detected. Even if a magnet stops directly in front of the KY024 Hall sensor, the LEDs must not light up, because there is no movement.

For this reason, the analog value of the Hall sensor is considered instead of the digital value. If the analog value changes, a rotary movement takes place. A small offset has been integrated to compensate minor fluctuations that occur even without a rotary movement. A counter was programmed as a double safeguard, which also counts how often the analog value changes. The double protection is intended to prevent the Hall sensor from detecting a magnetic field at a standstill.

#include <FastLED.h>
#define LED_PIN 7
#define NUM_LEDS 6
CRGB leds[NUM_LEDS];


int analogPin =A0;
int analogVal; // analog readings
int detector =0;
int firstVal=0;
int HIGHcount=0;


void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);//pinMode (led, OUTPUT); 
  pinMode (analogPin, INPUT); 
  Serial.begin(9600);
  
}

void loop() {
  analogVal= analogRead(analogPin);
  detector = abs(firstVal-analogVal);  //if there is a difference >0 then the wheel might be spinning
  firstVal=analogVal;

  if (detector>4)   //offset = 4 can be adjusted
  {
    HIGHcount++;  //counting the high to eleminate false positives  
    }
  else if (detector<=10)
  {
    HIGHcount=0;
  }

  if (HIGHcount>1)
  {
    YellowToRed(0); 
    delay(1000);
    HIGHcount=0;
    }

  else
  {
     for (int i = 0; i <= 5; i++) 
  {
    leds[i] = CRGB ( 0, 0, 0);
    FastLED.show();
    delay(30);
  } 
    }

}


void YellowToRed(int colorStep)
{
  for( colorStep; colorStep<250; colorStep+=5 ) {

      int r = 255;  // Redness starts at zero and goes up to full
      int b = 0;  // Blue starts at full and goes down to zero
      int g = 255-colorStep;              // No green needed to go from blue to red

      // Now loop though each of the LEDs and set each one to the current color

      for(int x = 0; x < NUM_LEDS; x++){
          leds[x] = CRGB(r,g,b);
          leds[x].maximizeBrightness(255-colorStep);
      }

      // Display the colors we just set on the actual LEDs
      FastLED.show();

      delay(50); 
  }
}

Pictures of the Hall Sensor Movement Detection

Download files

• Magnet Wheel (STL)

The post Hall Sensor Movement Detection appeared first on Nerd Corner.