robotmaker
Little while back someone made a post on home base finder ,and since it was so hard to find a good idea since there was many soloutions.
I decided to test one i found was very good thanks rgordon
First i put the circuit together and it worked very well
Second test is to use the arduino code to learn how it tracks
IR BEACON ROBOT TRACKING
3RD test is to convert the arduino code to EZB
It uses 4 IR transmitter and receiver pairs ,like a compass
it updates 1000 times per second as said on the pololu website
Alot faster then any camera or some other designs can do
here is a link about how it works
pololu ir beacon transceiver
also you need a set of them, one on your robot and one on home base
pololu ir beacon transceiver pair
Also they work great in the dark,so no lighting is needed ,will have photos and data as i make it
Unless I'm missing something (which I may be, the schematic is not exactly high resolution) where does it say it's digital?
Edit: Seems you edited before I finished typing. Is that digital then? I understand JP being jumper or link, nothing specifically digital. I'm not disputing you I am just asking as I don't know.
And unless you don't plan on attaching any servos, motors, h-bridges, ultra sonic, MP3 board, switches etc. you're going to end up with less digital ports left over than analogue.
Analog is for measuring distance,this one is about tracking distance
LIKE the way the IROBOT ROOMBA beacon design is made ,but this adds more
ROOMBA beacon uses only 3 ir beacons 2 at angle and 1 in the middle
so you only getting about 90 deg about
ON pololu design it uses 4 IR beacons at 360 deg plus very fast updating 10000 per second
SO IT SEE FOWARD ,BACK AND SIDE TO SIDE and anything in between
look at JP4 all connections are ground ,so if you jumper to JP3 will be grounded and leds with be always on
Also if you look at the circuit its only ouput
now this is a way to make your own circuit using IR MODULE like in the circuit without the nicroprocessor
And use EZB instead,it would need a PWM to analog CONVERTER, but that idea is way over most people head to design ,except for me
IR using one of our sharp IR sensors DJ sells,it can work too ,but may have a problem with interference
Some of my tech info i know its hard to understand unless you have a degree or something close to it
ALL i can do is try to explain it,so its easy to understand
The beacons work by transmitting and detecting infrared light, much like a television remote control. Each beacon has four IR emitters and four IR detectors. The beacons alternate between transmitting and receiving so that they never get confused by reflections of their own transmissions.
The transmit and detect cycle is carried out more than one thousand times per second, and a small microcontroller monitors all four detectors to decide the direction to the other beacon. The beacons have four red LEDs that indicate the direction to the other beacon; if you take two beacons and rotate them, the LEDs will always keep lighting up in the direction of the other beacon.
Interfacing to the beacon is simple - it has four digital outputs that indicate which of its four sides detects the other beacon the strongest. You can establish the direction to another beacon to within a few degrees by rotating the beacon back and forth and noting the point where the output switches from one side to another. An enable input lets you select between active mode and a low-power mode.
#include <Servo.h>
#include <AFMotor.h>
#define TOPSPEED 200
// servo SCANNING VARIABLES //
Servo myservo; // create servo object to control a servo
int servoPosition = 0; // variable to store the servo position
const int SERVO_PIN = 10;
int floorState = 0;
long frontReading = 0;
boolean scanIncrement = true; //increase position?
byte servoIncrementValue = 6;
byte servoDecrementValue = 6;
// MOTOR VARIABLES //
AF_DCMotor rightMotor(4, MOTOR12_8KHZ);
AF_DCMotor leftMotor(3, MOTOR12_8KHZ);
// TRANSCEIVER VARIABLES //
int notFoundSensitivity = 500;
int west = 0;
int south = 0;
int east = 0;
int north = 0;
int dir = 0;
boolean detected = false;
// TRANSCEIVER DIRECTION MODE VARIABLES //
const int NUM_READINGS = 10;
int directionReadings[NUM_READINGS];
int modeOfDirections = 1;
int index = 0;
void setup()
{
Serial.begin(38400);
myservo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object
myservo.write(0);
rightMotor.setSpeed(200);
leftMotor.setSpeed(200);
delay(1500);
}
You may be correct that its digital
My reference to adc ports is because I use them to monitor the outputs from the IR Beacon at present and it works very well .
Please may I move the post forward
@Rich is concerned about using up to 4 ports (digital or Adc)
my proposal is to try to limit it to one ADC
I am simply putting the idea forward
If we were to add a potential divider to all the outputs ( using a different value resistor in all 4 circuits ) could we then use one ADC to identify which ir N,S,E,W is active
e.g
1 volt on adc0 North
2 volt on adc0 South
3 volt on adc0 East
4 volt on adc0 West
I assume on the ADC port it is either low of 0v and high of 5v or vice versa?
@Rich
on the adc (ez-b ) it monitors any voltage between 0 and 5v ,as i listed in previous post
I will test the idea,or if someone can suggest a specific component I would appreciate
would a 4 input D to A converter meet our requirements *confused*
I note from your posts that you are an expert in circuit design
Would appreciate very much ,when you have the time to upload a schematic of a circuit to monitor the 4 outputs and produce a corrosponding voltage that could be monitored by the EZ-B adc port
Pat
And not shore is it will update as fast at 100000 per second
on digital is aways faster then anolog ,main reason analog first reads ther valule and then converted to digital
SO using digital the conversion is direct and faster
there is a simple circuit to use only only 2 digital ports with 4 digitals using gates
AND after me reading my info again on A-D conversions its not faster
TO make a D-A CIRCUIT will take a lot of parts,and each time a circuit is added to another circuit it slows it down.
I GUESS really need to read up on a A-D on how it works and design and the speed to fully understand it.
on D-A conversion is a voltage string depending on the bits and then a comparator for each bit and then a digital cicuit to convert it
would the ic in link be suitable eventhough its an 8 bit input
http://www.ti.com/lit/ds/symlink/dac0800.pdf
If one is not into schematics please you dont need to understand this is all in a single component
and the cost is only a few $ or £ or ?
thinking you use ezb Analog will give about 2500 per second and then need to divide another by 4 again is 625 updates per second ,on the digital you get 10000 updates per second
Only reason that you want a very fast updating is because you want the robot to turn left or right to stay on track to the home base finder or it would wonder all over the place
IT same about using a camera to find GLYPH you need it very fast to update the servos
I DONT thing the camera can update as fast at 10000 updates per second
will test circuit like I said and willl post results
Pat
in that circuit you need a good reference circuit and op amp to convert non inverting and inverting inputs to analog output
look near the end of the pdf file you put up
its the second link third one is pololu ir beacon tranceiver pair
The DAC0800 series are monolithic 8-bit high-speed 2. Fast Settling Output Current: 100 ns
current-output digital-to-analog converters.
i and i didnt see it was that slow i thought it would be much higher ,might be cause it 8 bits or type of design 100ns witch is 100 nano per second
it alot of different ideas
docking logic
there are over 50 pages just to let you know,i did print all of it about 5 years ago
When i was really into the finding home base designs and testing all types
IR DOCKING DESIGNS
GO TO CHAPTER 3 on IR docking it talks about why a omnicone is so very important
Also the cost is about $15 ,and may need 5 digital I/O PORTS ,but also ordered a chip to use I2C buss and have a extra 8 digital I/O inputs ,chip is under $1
Since the pololu IR BEACON design doesnt have it
most likeky wont get it done before i leave friday on my long work trip
but will be able to run tests on the pololu IR design to collect data,pwm and timming and more.