sharp IR calibration problem

[sirius86]

hello everyone,

im making the $50 robot and came across a big problem! im using all the specified electronics mentioned for this robot like the atmega8, sharp IR, hs311 servo. i havent constructed the chassis yet. but the circuit is done. but i cant calibrate the IR rangefinder. iv modified the two wheel servos, but kept the rangefinder's servo unmodified...isnt tht the way to do it? after mounting the rangefinder on the unmodified servo, iv tried calibrating it, but failed. i held an object (servo box, cd case, etc.) in front of the rangefinder at approximately 4inches away and then plugged in the battery. the rangefinder servo just moves to one direction and stops and doesnt react anymore, but the wheel servos keep rotating in the same direction, i.e. the robot wud keep moving in circles! iv tried using a different rangefinder, different microcontroller, burned the codes twice but still the same plz help me or redirect to discussions which myt help.....thnx all!

[SmAsH]

okay, are you sure its plugged into the right port?
also, have you checked the board for possible shorts?

[Conscripted]

Which program do you have loaded?

Conscripted

[sirius86]

thnx for ur replies!

iv tried the right ports and the wrong ones! i even did the connectivity test and everythin was fine, i used ponyprog to burn the microcontroller.......

[Razor Concepts]

Is there a common ground between the servo on the rangefinder and the MCU?

[Conscripted]

thnx for ur replies!

iv tried the right ports and the wrong ones! i even did the connectivity test and everythin was fine, i used ponyprog to burn the microcontroller.......

Are you using the sharp IR file from the tutorial? Did you modify it in any way?

Conscripted

[sirius86]

im having the same problems as Conscripted!

yes i used the IR file from the tutorial and did not modify it in any way...

//automatically calculates threshold value before run
void autocalibrate(void)

      {
      scan_thresh=a2dConvert8bit(3);//sensor reading
      }

shud i write a hardcoded number like 40 in place of "a2dConvert8bit(3)" as it is mentioned in the tutorial? wat does writing 40 actually mean, 40 wat? hav u tried this Conscripted? lemme know...

[sirius86]

still no luck ppl...i tried changing the circuit n using the 9V n 6V together but still no results...tried diff input n output ports too...the photoresistors work fine with the light avoidance code...so circuit must be ok...even changed the sensor servo n the sensor itself...but cant get them to work anyway!!! im really getting fedup of this... plus the sensor servo gets hotter thn the wheel servos...so if anybody can help plz dooo... tried diff things with the codes too...