Let's Make Robots!

No load resistor

I'm working with a psoc micro and many of the schematics they provide have "no load resistors".  I was just wondering if anyone here knew what a no load resistor is?

Stuck Code

It appears that If an object is really close to the SRF05 sensor the code will get stuck.  I'm thinking this is because an interrupt occurs while i'm waiting for a pulse from the SRF05.  since the object is close the pulse is short and ends before the program returns from the interrupt.  I've tried to disable interrupts for just that short period of time but that isnt working. 

my code looks like this  (if you'd like to see more just ask)

        bcf        INTCON,GIE ;temporarily disable interrupts

Navigates around avoiding walls
Using a
This is the first robot I built.  It drives itself around trying its best to avoid running into walls and other objects.  most of the circuitry has been done for … Read more

Programming a pic in linux

I would like to find a programmer for the pic microcontroller that is supported in linux.  currently I've been using a programmer that works well in windows but I havent been able to get it to work in linux.  I've thought about making my own but most of those require a serial port and I don't have one.  It also appears that some people have gotten the picstart plus to work in linux but I don't want to spend that much for just a programmer.  

I need a programmer that uses the USB port and works in linux.  any ideas?  

Software PWM

I was hoping to avoid wrighting my own software pwm for the pic but it looks like i've arrived there.  the motors and tracks I hot glued toghther don't drive straigh so the only way I can think of fixing it is to use PWM to slow down one motor.  I know I could use the one hardware pwm to slow down just one motor but thats going to be used in the future for somthing else so I have to create the pwm myself in software.


I was looking into my pic 18F1220 and I see that it has an internal oscilator that can be used as the clock.  I'm not sure how to enable this.  with my pic 16F84A I just hooked up a resistor and capacitor to the clock input and it worked.  I'd like to use the internal if possible since I dont have an oscillator and the RC mode seems to be a little slow.  I've been looking at the data sheet but its still a little confusing. 


I got a pic 16F84A as a free sample.  so far i've just hooked it up to a 7 segment display and it counts up to 9 and back down to 0 and repeats.  I've also hooke it up to some leds and flashed some basic patterns.  I think i'm ready to try something else now.  I ordered some tracks and motors to play with.  hopefully i can figure out how to get a range finder working too.