Android – IOIO – RC Servo (or ESC)

This is a sequel to my first Hello World example with the IOIO / Android setup….

Android + IOIO controlling a RC servo

Random Project Box

…there’s not much to say about this one afternoon project… except that I have no idea what to do with it… !

I’m more than open to any interesting suggestion…

Project Box Final

Hello IOIO – Android

Hello IOIO Android

Here’s (finally) my first attempt at programming an Android phone AND interacting with the physical world at the same time… !

SRF05 Ultra-Sonic Ranger

I’ve just spend a couple of hours preparing this ultra-sonic ranger and the necessary code to integrate it into my autonomous tank project.

Here’s a quick post briefly explaining the theory and providing some Arduino code for it.

SRF05 in all its glory

Kalman filter – simplified version

Finally… it’s been a while since I’ve started looking into filtering, and more precisely Kalman filters… since I started on my quadcopter project, to be more precise…

After reading the descriptions and formulas found here (highly recommend the short introductory pdf !) I decided I had to code my own simplified version.

Kalman filter applied to input from a noisy FM receiver

Tiger 1 BB airsoft RC Tank – V3

This is the sequel of 2 other posts describing previous work on this project:

• version 2 of the tank attempt
• and the initial work which dealt more with the low level building.

It also builds on this previous post, which is all about interfacing the WiiMote IR Camera with the NXT and tracking an IR LED with a Lego motor.

11Jun2011 – FINALLY !!!

Everything seems to work nicely together now it not only tracks and locks on the target, but it finally shoots PLASTIC PELLETS !

WiiMote IR Camera with Lego NXT Brick – LeJOS

This previous post talks about how to connect a IR Camera from a WiiMote to an Arduino.

There’s also this one, talking about how to connect it to the .NET micro framework, FEZ Domino board (which also has hardware details on how to extract the mentionned camera and solder it on its own little board…).

It’s therefore time I wrote a quick post, on how to interface this wonderful camera with a Lego NXT Brick, programmed in Java thanks to LeJOS !

WiiMote IR Camera and Lego NXT - LeJOS

WiiMote IR Camera with Arduino

This post shows how to extract the IR Camera from the WiiMote and connect it to a .NET micro framework board (FEZ Domino in my case).

The present blog is simply a porting of the C# code to Arduino code, in case anybody is interested…

It’s a very basic file, really showing just the minimum necessary to get it working.

#include <Wire.h>

const byte ADDR_SENSOR = 0xB0 >> 1;
byte buff[2];
byte recvBuff[13];

int x, y, s;

void setup(){
Serial.begin(115200);
Wire.begin();

send(0x30, 0x01 );
send( 0x30, 0x08 );
send( 0x06, 0x90 );
send( 0x08, 0xC0 );
send( 0x1A, 0x40 );
send( 0x33, 0x03 );
send( 0x30, 0x08 );

delay(100);
}

void loop(){
readData();
Serial.print(x); Serial.print(" / "); Serial.print(y); Serial.print(" / "); Serial.println(s);
delay(300);
}

void readData()
{
send( 0x36 );
Wire.requestFrom(ADDR_SENSOR, (byte)13);
for(byte i=0; i<13; i++) recvBuff[i] = Wire.receive();

// have no idea why the 1st BLOB start at 1 not 0....
byte offset = 1;
x = recvBuff[offset];
y = recvBuff[offset + 1];
int extra = recvBuff[offset + 2];
x += (extra & 0x30) << 4;
y += (extra & 0xC0) << 2;
s = (extra & 0x0F);
}

void send(byte val){
Wire.beginTransmission(ADDR_SENSOR);
Wire.send(val);
Wire.endTransmission();
delay(10);
}

void send(byte val1, byte val2){
Wire.beginTransmission(ADDR_SENSOR);
buff[0] = val1; buff[1] = val2;
Wire.send(buff, 2);
Wire.endTransmission();
delay(10);
}

Tiger 1 BB airsoft RC Tank – V2

It’s all about the same project as here, BUT with a different technology: instead of using the FEZ Domino (.NET micro framework based) board, I’ll be using the Lego NXT controller and an Arduino board for low level interaction with the electronics.

NXT + Arduino internals

My first H-bridge

While working on my latest autonomous tank project, something very annoying happened: I needed to control 2 motors for the turret and the firing of the gun, BUT out of the 3 completely different motor controllers that I had laying around (a L293D based one, a pololu serial controller and a micro RC ESC) NONE was working… !!!

This was so frustrating, that it forced me to want to build my very first H-Bridge from scratch. This is something I had always avoided, thinking that “I had better things to do”, ie spend time on higher level stuff …

I started with this schema, taken from the Internet and slightly modified (it initially used 2.2KOhms resistors, but on all the other sites people were using 1K, as a better compromise):

TIP120 base H-Bridge motor controller