RC servo example

[ddlawrence]

Hi. I am having great success with my MiniPod. I can handle RS232 i/o, inter-machine
communication and digital i/o so far.
Now onto RC servo control. I entered the example you provided in IO Glossary.
It is pasted here:

DECIMAL

: SET-RC-SERVO

3277 100 */

3277 +

TA0 PWM-OUT

;



50000 TA0 PWM-PERIOD

TA0 ACTIVE-HIGH



50 SET-RC-SERVO


Now I think I understand what this does. And to move the servo enter:

80 SET-RC-SERVO

20 SET-RC-SERVO

etc...

However nothing happens. I checked the servo and swapped in another
working one of different manufacture. No go.
I checked power on the middle pin.
I checked (with a voltmeter) the signal pin. It remains constant at 2.50V
I tried TA0, TA1, TA2 & TA3 to no effect.

Am I missing something?
Can I check some registers or some other very simple test to see
if I can set it full on high or low?

thanks.........don

[nmitech]

Besure to have the Servo power input, 4-6Vdc applies to J5 connector. Please see the schematic link below for proper pinouts connection,
http://www.newmicros.com/store/product_schematics_pdf/minpod.pdf

Do not use 5V from the controller circuit to power the Servo. Most likely, it will cause the controller resets when the motor starts moving because the Servo draws more power at startup than the onboard 5V regulator can handle.

[ddlawrence]

Yes, I have a second NiCAD batterypack providing servo power on J5.
And I measure 5.0V on the J1 connector power pins (middle row).
The servos are new and checkout ok on the Futaba & Hitec RC gear,
interchangably I might add.

..............don

[nmitech]

The code you tested with is working just fine here. I tested with Futaba S3003, and GWS S03TXF-2BB servo's that i found on my lab. So i guess you might have the servo connected on the wrong pin for TA0. If you are looking on J1 of the MinPod board, the first two rows do not have header pin, and the third row and up has header pins installed. Where TA0 should be on the 1st row (inside pin) with header pin installed. The reason for row1 and row2 of J1 do not have the header pins install just to avoid the confusion with the Servo header connections. So it maybe less confuse to count the signal pins from J5 pins instead.

[ddlawrence]

Yes that was it! The first 2 rows of J1 do not have pins. So that caused me to
plug into the wrong row. The servo works great now. Maybe put a note in the
Minipod manual to save the next guy 2 days of grief.
Anyway, alls-well-that-ends-well.
Now that I am satisfied I can use your Pod I am buying a couple Plugapod Dev kits
and get going on this next job.

thanks again........don