Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: fotografas on January 04, 2011, 09:25:27 AM

Title: Sensors, H-Bridge, main circuit
Post by: fotografas on January 04, 2011, 09:25:27 AM

Hello
I am new in this forum and this is my first post. So please don't punish me too hard if something goes wrong :]

So, I need some help with my project. Especially with electronics.

In this circuit you can see, the main board - Atmega16. Also 8 sensors with IR transmitter and IR receiver circuit. Moreover, there are circuit for motor- H-Bridge, L293D. I am also planing to use PWM.  For detecting obstacles, I have already bought ultrasound sensor (transmitter and receiver). Every circuit have her own by-pass. Also there are three different power supplies.  LM7805 for Atmega16 , H-Bridge, IR and ultrasound sensors. LM317 for motor. They need 3V each. There will be two motors.  And also LM7809 for ultrasound sonar.
 I am planing to use 3 Li-ion battery's for whole robot. They are from laptop battery. Each one is 3,7V and 2200mah

All the mechanics are almost done. But its not about that. I have some problems with all whose circuits.
There is "Ping" contact in ultrasonic transmitter. And "Frequency_Test" in ultrasonic receiver. I don't know where to connect them. I mean to which contact of At-mega16 I should connect them.

Also H-Bridge. There are contact 1A, 2A, 3A, 4A in L293D. Can I connect them to PD0, PD1, PD2, PD3 of ATmega16?

And the whole IR circuit. Is it schematically good?

Thanks in advance for all of You, who helps me :]

PS. sorry for the mistakes. My English skills aren't good enough.
 

Title: Re: Sensors, H-Bridge, main circuit
Post by: Soeren on January 05, 2011, 10:57:51 PM

Hi,

Quote from: fotografas on January 04, 2011, 09:25:27 AM

And the whole IR circuit. Is it schematically good?

No, T1 should be where either R2 or R3 is (depending on the action wanted; dark or light sensing).
As it is it will do nothing but change the impedance of the circuit a bit, but the voltage will still be close to 2.5V.
(It will change slightly, of course, due to the impedance change, but in the right place, you'll get a lot more amplitude change).

The resistor you keep (R2 or R3) should probably be a bit larger in value )depending on the photo transistor).