hweontey

How 's difference between these sensors, IR sensor, ultrasonic sensor and sonar sensor???

which sensor i should use, if robot detects obstacle in the afternoon or night ??

how can i get the information??

10s!!

pitronix

I think that last two are the same kind of devices, they use sound as sort of medium for finding obstacles, IR use infra red light emision to finde obstacle. Use depends of range and other factors. You should give more infos about exactly what you want to do.

__________________
Aude, Vide, Tace

dknguyen

Ultrasonic and SONAR are the same thing.

Ultrasonic-
-time of flight distance measurement
-longer range than IR
-affected by wind
-affected by hardness of object

IR-
-angle (parallax) distance measurement
-shorter range than SONAR
-affected by sunlight
-affected by colour of object.

Personally, I prefer sonar jsut because it has a longer range and uses time-of-flight to measure distance which I just prefer over the parallax measurement that IR uses. PLus I know (in theory) how to get more data out of sonar than just the time-of-flight. Parallax measurement also tends to mean that the longer maximum range you have also increases your minimum range. This does't happen with TOF.

IR can be cheaper and smaller though. Plus sensing with light is a bit cooler than sensing with sound. THe only way to do TOF with light (or EM waves) is radar and yeah...you can imagine how much it costs to measure the time of something travelling at the speed of light (there's one that can scan and is $2.3K but only works until 4m and everything else is $10K+ for the most part but these ones can work for miles).

danny仔

Oic, i was doing the project that call as blind aid, using ultrasonic to measure distance and tell the blind how far is the obstacle left.

Ultrasonic is better then IR in this case..

__________________
Learn a lot for being here

seesy1234

how i connect the PIC 16A84 with the ultrasonic sensor.have any schematics?then how to show how far is the obstacle left on LCD.THX

futz

I highly recommend Maxbotic sonar sensors. Good accuracy and easy to interface.

They have three interface methods available on every sensor - pulse width, analog voltage and asynchronous serial. Analog is usually the easiest to use.

__________________
=========================
Futz's Microcontrollers & Robotics
=========================

seesy1234

hey,futz.if i wan build my own the obstacle detector,do you have any idea how to build it.actually my project is remote control car.i using PIC16F84A to control the motor and it also can detect the obstalce.when it detect obstacle,it send the signal to LCD and then the LCD will show the how far distance from obstacle.

Attached Files

remote car.zip (16.3 KB, 5 views)

futz

How about the sensors used on Solarbotic's Sumovore? They're simple, reliable and good for probably 12 inches sensing range or a bit more. You can get the schematic here. Look on Page 29 for the Full Schematic. You're looking for 38khz IR Object Sensors and 38khz IR emitter. Parts list is somewhere earlier in the doc.

__________________
=========================
Futz's Microcontrollers & Robotics
=========================

seesy1234

hey,futz.In my place here don't have sold this sensor QRD1114 Edge Sensor..if i want brought then i need online to buy.but it's over my budget because parents just give me RM200 dollor in m'sia.do you know how to modify page 9 on this website
http://forum.cxem.net/index.php?act=...=post&id=21658
using PIC16F84A to instead the TX-2B and RX-2B.

seesy1234

i need do the final year project.actually i not very clear in the circuit.do you have any idea that have schematics and programing code but must have application.thanks for futz always give me idea

seesy1234

hey,futz...do you know how to make self-learning remote control car.For example if i control the car using remote control and let it move to 1 track or 1 around.when i press a switch ,it will follow back the previous track that i control without controlling by user.i using the PIC16F84..i don't know how to store the previous instrcution that i control the track and save it in memory..any idea.thanks..

__________________
hey,guys