Test run with RC Surfer/ Homemade Spot Welder

I'm currently doing at least two projects at a time (and more in the queue) which I will elaborate later on in this blog.

Spot Welder

Spot welder test

The first project is a homemade spot welder which I'm building together with Knudt and Sebastian for the Hamburg Makerspace Attraktor. The device will be used for connecting rechargeable battery cells or join together thin sheets of metal. The whole thing consists of a 1 Farad/ 16V Capacitor (originally used for car hifi), a 13.8V/ 2A power supply, some Mosfets and an Arduino with a graphical display (at the moment it's a Nokia 5110 LCD display). The Arduino will do the controls, while the Mosfets will handle the power dissipation to the electrodes.
On the right there is a picture of an early test. You can see the capacitor in the background, on the breadboard there is an Arduno Nano and the Nokia LCD display. We are using scrap steel "electrodes" at the moment but will possibly change this with real tungsten welding electrodes.Oooh, and obviously no XBees involved this time.

RC Surfer

Years ago I bought a so called "RC Surfer" for cheap (you have to google this because mine is disassembled and I can provide no photo in action).

Cheap were also the contents of this RC controlled surfer. There was a motor driver with a relay, a 27 MHz radio control and a servo controlling the rudder. The power control was only "on" and "off" and the servo reaction to the input on the remote control was at least working.
There was no feedback of voltage or temperatures and no extra features like light etc.

 

At the moment I'm working on the new motor controls. I have a prototype L298 motor driver board which supplies at least 2A to the original dc brushless motor I'm still using. It consumes about 1A so I'm happy with the L298 for now. You can control the motor speed by using the PWM on the Arduino and connect it to the enable pin on the L298. You can also power the motor forward and backward what was not possible with the original motor driver.
The first test run worked quite well and the next addition will be the rudder control with a new servo. At the moment I'm using a joystick out of a scrap PS2 control - later I will command the RC Surfer with my android phone and a bluetooth connection. If that doesn't work, I will use a XBee/ RC combination with a traditional remote control.
Possible features might be telemetry which sends data like current used, voltage, temperatures, cam etc. Or what about a water canon?

to be continued...





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Electronic compass part 2

This is part 2 of the electronic compass with the video and the Arduino sketch.

Video:

Sketch:

/*****************************************
 * Compass with Pollin HDMM01-compass-module
 * and Nokia 5110-display
 * Last edit: 3.1.2013
 * By Markus Ulsass
 ******************************************/

/*******************************************************************************
 * This is an example sketch for our Monochrome Nokia 5110 LCD Displays
 *
 * Pick one up today in the adafruit shop!
 * ------> http://www.adafruit.com/products/338
 *
 * These displays use SPI to communicate, 4 or 5 pins are required to
 * interface
 *
 * Adafruit invests time and resources providing this open source code,
 * please support Adafruit and open-source hardware by purchasing
 * products from Adafruit!
 *
 * Written by Limor Fried/Ladyada  for Adafruit Industries.
 * BSD license, check license.txt for more information
 * All text above, and the splash screen must be included in any redistribution
 *******************************************************************************/

#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>

#include <Wire.h>

#define  I2ADDR       0x30
#define  TakeMeasure  0x01
#define SET_COIL 0x02 // set magnetic coil
#define RESET_COIL 0x04 // reset magnetic coil

// pin 7 - Serial clock out (SCLK)
// pin 6 - Serial data out (DIN)
// pin 5 - Data/Command select (D/C)
// pin 4 - LCD chip select (CS)
// pin 3 - LCD reset (RST)
Adafruit_PCD8544 display = Adafruit_PCD8544(7, 6, 5, 4, 3);

int r = 24;  // radius of compass rose
int x0= 60;  // x-origin
int y0 = 24; // y-origin

void setup()   {

  // Serial.begin(9600);

  display.begin();
  display.setContrast(60);
  display.clearDisplay();

  Wire.begin();

}

void loop() {

  ResetSetCoils();
 
  byte MsbX,LsbX,MsbY,LsbY;
  int x,y;
  char line[80];
  Wire.beginTransmission(I2ADDR); // Pollin HDMM01 address
  Wire.write(0x00);  
  Wire.write(TakeMeasure);
  Wire.endTransmission();
  delay(20);
  Wire.beginTransmission(I2ADDR);
  Wire.write(0x01);
  Wire.requestFrom(I2ADDR, 4);

  while(Wire.available()<4);
  MsbX  =Wire.read();          // upper  4 Bit X
  LsbX  =Wire.read();          // lower 8 Bit X
  MsbY  =Wire.read();          // upper 4 Bit Y
  LsbY  =Wire.read();          // lower 8 Bit Y
  Wire.endTransmission();         // stop transmitting
  x=((MsbX&0x0f)*256)+(LsbX);
  y=((MsbY&0x0f)*256)+(LsbY);
  x = map(x, 1960, 2151, -180, 180);
  y = map(y, 1939, 2131, -180, 180);
  double mygrad = atan2(-x, y)*180/3.1415927410;
  if (mygrad < 0)    mygrad = mygrad +360;
  int angleActual = mygrad;
  // Serial.println(mygrad); // debug
  delay(200);

  // Calculation of compass needle on lcd pointing to the direction
 
  if (angleActual >= 0 && angleActual <=45) {
    // 0-45 degrees
    int angle = angleActual/2;
    display.drawLine(x0, y0, x0+angle, y0-r, BLACK);
    // 45 degrees
    // display.drawLine(x0, y0, x0+r, y0-r, BLACK);
  }
  else if (angleActual >45 && angleActual <=90) {
    // 46-90 degrees
    int angle = (angleActual-44)/2 ;
    display.drawLine(x0, y0, x0+r, (y0-r)+angle, BLACK);
    // 90 degrees
    // display.drawLine(x0, y0, x0+r, y0, BLACK);
  }
  else if (angleActual >90 && angleActual <=135) {
    // 91-135 degrees
    int angle = (angleActual-90)/2;
    display.drawLine(x0, y0, x0+r, y0+angle, BLACK);
    // 135 degrees
    // display.drawLine(x0, y0, x0+r, y0+r, BLACK);
  }
  else if (angleActual >135 && angleActual <=180) {
    // 136-180 degrees
    int angle = (angleActual-134)/2;
    display.drawLine(x0, y0, (x0+r)-angle, y0+r, BLACK);
    // 180 degrees
    // display.drawLine(x0, y0, x0, y0+r, BLACK);
  }
  else if (angleActual >180 && angleActual <=225) {
    // 181-225 degrees
    int angle = (angleActual-178)/2;
    display.drawLine(x0, y0, x0-angle, y0+r, BLACK);
    // 225 degrees
    // display.drawLine(x0, y0, x0-r, y0+r, BLACK);
  }
  else if (angleActual >225 && angleActual <=270) {
    // 226-270 degrees
    int angle = (angleActual-222)/2;
    display.drawLine(x0, y0, x0-r, (y0+r)-angle, BLACK);
    // 270 degrees
    // display.drawLine(x0, y0, x0-r, y0, BLACK);
  }
  else if (angleActual >270 && angleActual <=315) {
    // 271-315 degrees
    int angle = (angleActual-270)/2;
    display.drawLine(x0, y0, x0-r, y0-angle, BLACK);
    // 315 degrees
    // display.drawLine(x0, y0, x0-r, y0-r, BLACK);
  }
  else if (angleActual >315 && angleActual <=360) {
    // 316-360 degrees
    int angle = (angleActual-312)/2;
    display.drawLine(x0, y0, (x0-r)+angle, y0-r, BLACK);
    // 360/ 0 degrees
    // display.drawLine(x0, y0, x0, y0-r, BLACK);
  }

  // text display

  // display.drawCircle(x0, y0, r-1, BLACK);
  // Display actual heading
  display.setTextSize(2);
  display.setTextColor(BLACK);
  display.setCursor(0,0);
  display.println(angleActual);
 
  display.setTextSize(1);
  display.setTextColor(BLACK);
  display.setCursor(x0-2,0);
  display.println("N");
 
  display.setTextSize(1);
  display.setTextColor(BLACK);
  display.setCursor((x0+r)-5,y0-3);
  display.println("0");
 
  display.setTextSize(1);
  display.setTextColor(BLACK);
  display.setCursor(x0-2,y0+r-8);
  display.println("S");
 
  display.setTextSize(1);
  display.setTextColor(BLACK);
  display.setCursor((x0-r)+5,y0-3);
  display.println("W");
 
  // Triangle for direction
 
  // display.drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint16_t color)
  display.drawTriangle(0, 46, 20, 46, 10, 18, BLACK);
  // fillTriangle ( int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint16_t color)
  display.fillTriangle (0, 46, 20, 46, 10, 18, BLACK);
  display.display();
  delay(100);
  display.clearDisplay();

}

void ResetSetCoils (void)
{

    // RESET / SET Coils
    Wire.beginTransmission(I2ADDR);
    Wire.write(0x00);
    Wire.write(RESET_COIL);
    Wire.endTransmission();
    delay(1);
    Wire.beginTransmission(I2ADDR);
    Wire.write(0x00);
    Wire.write(SET_COIL);
    Wire.endTransmission();
    delay(1);
}

Electronic compass

Just a note to a little project I'm building at the moment - an electronic/ digital compass:

There is no XBee involved - but a Nokia5110 lcd display, an Arduino Nano, a 2-axis compass module (HDMM01) and a HCF4050 for level-shifting. Of course you could add a XBee if you are using the compass for a robot or other mobile project.

And yes - the Halloween project is still to be posted. Just give me some more time.