Cyborg

Hey I build this robot which works for me and sometimes it gives me problems. I'm using PIC16F628 with 2 futaba standard motors and a 9v batt . So would anybody give me an advice or any suggestion if I'm doing the right thiung or not. The connections are like this, power pin connected directly to 9v, mclear pin directly too, servos too are connected directly and I have a speaker too 8 ohm which is connected directly to the 9v.
So I dont know whether there are places that I need resistors and other components. I wish I had the schematic.

Exo

The pic's power line is connected to 9V directly? :shock: ...

The maximum supply voltage for a pic is 6V...
You need a voltage regulator to drive your pic, a 7805 for example...

Depending on how long you've put 9V on your pic it might be dead...

And connecting a speaker to 9V directly , what would that accomplish?

Cyborg

Oh, the speaker was connected to the PIC, I'm sorry.

Oznog

And the PIC pins can't drive high enough currents for a motor, unless it's very small and has little load. Note that after you put on a 5V regulator, the pins will only output 6V. You need an H-bridge to drive some power transistors which can switch higher currents all the way to +9V and Gnd.

evandude

by "futaba standard motors" he might mean he's using hacked servo motors, which have their own motor drivers, you just give them a signal to determine the direction and speed;

and yes, you definitely need a regulator to power the PIC