Day Two~

The first thing we attempted to do today was mount a wireless digital camera to the blimp to see if the blimp could lift both camera and the motor board. Result: crashing nose first into the ground. The motor board itself is roughly 80 grams, but the digital camera is roughly another 80 grams. Even after attempting to push all the air out with a straw and refilling with helium, there was not enough lift to carry camera and board. We also took apart the camera and attached only the camera with it's board, but it still was too much weight. Our next step is to get rid of the Li-Ion battery on the camera and connect the camera to the LiPo battery on the motor.

Next came the RC. We test the settings for almost an hour until we figured out what would work best. While DIY said to plug the servo plug into throttle, we plugged it into elevation instead. We then plugged RC1 and RC2 into throttle and rudder. With our RC controller, the left stick controlled the throttle forward and reverse, while up and down on the right stick controlled the angle of the servo for the up and down, while left and right turned the fans on the right and left side respectively. There were some issues though. The throttle control was a little off: reverse was much stronger then forward. Basically, neutral was still going in reverse, and all the way forward was barely going forward. We'll probably have to go into the RC control to modify that, which I'll poke into this weekend. Also, rudder control was a little ungainly. I think that another one of the plugs will allow better turning; ideally, to turn left, right motor spins forward while left motor spins backwards. This will allow for much tighter turner. That'll be for Tuesday.

Ultrasound came next. While in the previous video (see about three posts prior) I was able to make the fan spin high or low depending on the length of the signal that came back, it would only spin low for small distances and high for large distances. So, I did the following:

//ultrasound mark 2

int usi = 16;
int uso = 15;
int rm1 = 2;
int rm2 = 3;
int lm2 = 5;
int lm1 = 4;

void setup()
{
Serial.begin(19200);
pinMode(usi, INPUT);
pinMode(uso, OUTPUT);
pinMode(rm1, OUTPUT);
pinMode(rm2, OUTPUT);
pinMode(lm2, OUTPUT);
pinMode(lm1, OUTPUT);
}

void loop()
{
int length = 0;
digitalWrite(uso, HIGH);
delay(40);
length=pulseIn(usi, HIGH, 200000);
digitalWrite(uso, LOW);
length=(length/147); //pulse width is 147us/inch so length is in inches
Serial.println(length);
if(length>=40 && length<=45)
{
analogWrite(rm2, 0);
analogWrite(lm2, 0);
}
if(length>45)
{
analogWrite(rm2, length);
analogWrite(lm2, length);
}
if(length<40)
{
analogWrite(rm2, 45-length);
analogWrite(lm2, 45-length);
}
}

This made it so that a distance of 40-45 inches from the ground was the idea hovering distance. Anything below that, the fan would spin at 40-d, where d is the distance from the ground, so the farther from the ground it got the slower it would spin and visa versa. Another thing that we confirmed was that the board ran using the digital pins TX and RX. This means we have to use two separate lines of code to send out a pulse and read the pulse (the 147 means 147 us/inch). The ultrasound also supports another pin, which is analog. This way, we would be able to have it do analogread to measure the distance of the waves; however, we're not sure if the board has a pin programmed for the analog on the ultrasonic.


Next we worked on the IR receiver and this was a bugger of an problem to figure out. I started with a code like this.

int IR_front = 8;
int IR_back = 7;
int IR_right = 6;
int IR_left = 9;
int ledn = 12;
int lede = 17;
int leds = 11;
int ledw = 13;

int vf = 0;
int vb = 0;
int vl = 0;
int vr = 0;

void setup()
{
Serial.begin(57600);
pinMode(ledn, OUTPUT);
pinMode(lede, OUTPUT);
pinMode(leds, OUTPUT);
pinMode(ledw, OUTPUT);
pinMode(IR_front, INPUT);
pinMode(IR_back, INPUT);
pinMode(IR_left, INPUT);
pinMode(IR_right, INPUT);

digitalWrite(ledn, LOW);
digitalWrite(leds, LOW);
digitalWrite(lede, LOW);
digitalWrite(ledw, LOW);
}
void led_off()
{
digitalWrite(ledn, LOW);
digitalWrite(leds, LOW);
digitalWrite(lede, LOW);
digitalWrite(ledw, LOW);
}

void loop()
{
vf = digitalRead(IR_front);
vb = digitalRead(IR_back);
vl = digitalRead(IR_left);
vr = digitalRead(IR_right);
Serial.print(vf);
Serial.print(',');
Serial.print(vb);
Serial.print(',');
Serial.print(vl);
Serial.print(',');
Serial.println(vf);


digitalWrite(ledn, HIGH);
digitalWrite(leds, HIGH);
diitalWrite(ledw, HIGH);
digitalWrite(lede, HIGH);

delay(10);
led_off();
}

When we ran the code, all the lights on the board turned on! It was weird. We then tried pushing a bunch of infrared remotes and nothing worked. Same with the IR beacon that came with the setup. The serial prints were just giving us 1's with an occasional 0. Then we turned off the beacon and the lights remained on. We turned them back on and that's when Prof Mason noticed the flickering. We turned off the beacon and the flickering stopped. Hmmmmm....perhaps it's backwards...instead of trigger High, like we thought, maybe the beacon made the IR trigger a low spot and that's what makes it detect it. To test it, we hooked up a spectrometer and turned off all infrared in the area....and we got two bars! The IR receivers were programmed on high! So we modified the code

int IR_front = 8;
int IR_back = 7;
int IR_right = 6;
int IR_left = 9;
int ledn = 12;
int lede = 17;
int leds = 11;
int ledw = 13;

int vf = 0;
int vb = 0;
int vl = 0;
int vr = 0;

void setup()
{
Serial.begin(57600);
pinMode(ledn, OUTPUT);
pinMode(lede, OUTPUT);
pinMode(leds, OUTPUT);
pinMode(ledw, OUTPUT);
pinMode(IR_front, INPUT);
pinMode(IR_back, INPUT);
pinMode(IR_left, INPUT);
pinMode(IR_right, INPUT);

digitalWrite(ledn, LOW);
digitalWrite(leds, LOW);
digitalWrite(lede, LOW);
digitalWrite(ledw, LOW);
}
void led_off()
{
digitalWrite(ledn, LOW);
digitalWrite(leds, LOW);
digitalWrite(lede, LOW);
digitalWrite(ledw, LOW);
}

void loop()
{
vf = digitalRead(IR_front);
vb = digitalRead(IR_back);
vl = digitalRead(IR_left);
vr = digitalRead(IR_right);
Serial.print(vf);
Serial.print(',');
Serial.print(vb);
Serial.print(',');
Serial.print(vl);
Serial.print(',');
Serial.println(vf);


if(vf==LOW)
{
digitalWrite(ledn, HIGH);
}
if(vb==LOW)
{
digitalWrite(leds, HIGH);
}

if(vl==LOW)
{
digitalWrite(ledw, HIGH);
}
if(vr==LOW)
{
digitalWrite(lede, HIGH);
}
delay(10);
led_off();
}

And Bam! Success! Another thing we did was put the beacon farther away, and that caused only one LED to light up. With the beacon too close, there was too much reflection and it caused all the LED's to light up.

So, things to work on.
1. Modify RC code for the throttle.
2. Get a small plug and wires for the battery
3. Get Robo Realm and the wireless camera to sync with my laptop.

That's everything I can remember. Anything to add Professor?