i am making a Servo driver/reader with atmega 168, it reads 9 servos and drives 9 servos.
Does this requires it to run on 16mhz crystal or is it good enough with 8mhz? ( having problem with fitting the crystal on my pcb).
Do I need to connect all vcc/gnd pins on the avr?
The servos are powered with 5-6volt from the motor regulator, this source is also going to power the avr. Do I need a 3.3V regulator and which one can I use, the smallest possible, and how big should the cap be for this.
Is it possible to drive the servos and meassure servo current with the same pin? (using adc pin and swap between input and output in software ?)
Can i use any pin to generate the total pulsetrain for the servos(to connect it to other devices etc) or the pwm pins?
Thanks for any tip on question
I am trying to make one like this, but which is a 1/3 the size and have serial output and can drive the servos and not just read them.. http://ppzuav.com/osc/catalog/product_info.php?products_id=91
I am using a double sided board and have the avr on side and the headers are smd instead of trough hole
Do I need to connect all vcc/gnd pins on the avr?
Yes it allows the chip to frame bonding to take the current specified in the spec.
Does this requires it to run on 16mhz crystal
No but the timing will be out on sevral things like millis() and the serial ports unless you change the files to compensate. Search for that here there have been many examples of changing the clock speed.
Do I need a 3.3V regulator
Yes
which one can I use,
any actually. http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=4WPZYFCLXPQPWCQLCIQJKBQ?N=500006+1002567+383057&Ntk=gensearch_001&Ntt=voltage+regulator&Ntx=&_requestid=428670
Take your pick
how big should the cap be for this.
I would use about 1uF but look at the spec of the voltage regulator for the recommended value, it changes with the regulator. If it is too small it could oscillate.
Is it possible to drive the servos and meassure servo current with the same pin
No. To measure current you have to break the drive line and insert a resistor. Then measure the voltage drop across the resistor.
Does this requires it to run on 16mhz crystal
Was thinking of running internal 8mhz, and select a differnt board then duamille nove, will still millis be off?
And how can i write a code to read 9 servo signals simultanious?
Kim