I need help to understand this...

i made a simple bot, it has an arduino s3v3 with a 328p atmega...

as actuators i have modified servos, calibrated to stop moving at digitalWrite(90)

so, when i ran first tests it worked good, using the sharp IR on a third servo it had good performance, in some places i ordered to stop by writing 90 on the servo pins and did well.... it stopped the servos...

then i added an 16x2 LCD display with a SERlcd v2 from sparkfun, made the software changes, conected the lcd display, managed to make it work......... it did well with the lcd...

but...

something strange is happening, now when i write (90) on both servos, they do not make a full stop... they keep moving a little to one side (as they do when not callibrated)

what can be happening??????

help please...

this is my bot...

Sounds like they need to be recalibrated. Anytime you change the circuit you shouldn't be suprised by the need to recalibrate. Even though your changes shouldn't have affected the servo, I bet if you take detailed measurements of the circuit there will be subtle changes in the various voltage because of the addition of the LCD.

If you just have the LCD on without sending any messages to it or even using it at all. That will tell whether having the display changes your calibration or using it makes some changes (like you're spending time sending out LCD messages and not attending to your motors as often as before.

so, it is normal that in every change i make on my circuit i have to calibrate my servos, in other words, calibration is specific to that circuit in that time....

i was afraid that i was a matter of timers or other big stuff....

thanks for the answers...

:D

Let´s recalibrate....