I feel vindicated (to a small degree)

Well, I guess I should get to know what I am buying a little bit better. I've been a bit frustrated playing around with the MCU's and the servos. I thought I was getting something very basic wrong. I decided to put it aside until my oscilloscope arrives.

I loaded up another piece of software I purchased recently called Tina. Tina lets me simulate electrical circuits. Much to my surprise, one of the features I discovered today allows me to also run programs on MCUs as part of a circuit. So I loaded my servo control program into Tina and simulated it. The screenshot shows the results of the simulation.

The thing to notice is the window to the upper right of the big yellow box. It shows the timing. That pulse it is showing should occur once every 20ms and the high peak should be between 1ms and 2ms. And that is exactly what Tina is showing.

So, why can't I get the servos to respond? Some possibilities.

* The chip is not running at the correct frequency. Unlikely since I've already tested with flashing LEDs to make sure I got the number I expected.

* Servos are defective. I don't expect this since I bought 3 and they are all working the same way.

* Servos don't work the way I expect. This is very possible

Anyway, once the oscilloscope arrives, I can verify my numbers coming off of the test circuit. I may also hit up the hobby store and pick up a different model of servo just to see if that is the issue. Also, if they have someone working that understands servos I may see if I can chat them up.