multiple servos using picaxe

A couple more questions

Is it better to use multiple picaxe chips to control multiple servos.
Say, for instance using an 8M chip with one servo attached and after this servo movement, make a pin go high which would activate another 8M chip
Would there be any advantage in this situation? Less feedback? Less gitter?
easier to fault find?

There are 4 servos in my project. I am using a 40x2 chip

Overall, is it better practice to use various chips in the same project or fit it all into one big chip if it will fit?


Unless there is a specific reason (eg code which requires the servo timer, or multiple tasks) to use more than one PICAXE, then don't. Electrically it won't do anything for you. Avoiding glitches is down to good design, throwing in more controllers actually makes it harder.


Since you are using a 40X2 as the main controller, you have plenty of IO and a good amount of program space.

So as BB has indicated, unless program space, total iO requirements or some other compelling reason occurs it is generally better to do everything in the one PICAXE chip.


Senior Member
If you're using serout, it will probably affect the servos. I tried driving a serial LCD display and a servo with a 28x2 and the servo glitches every time the LCD is rewritten (80 characters at 9600 baud).



Technical Support
Staff member
Background servo control will rarely be perfect in all circumstances on any single core, general purpose, interpreted microcontroller system, quite simply because when instructed to do something it cannot then be doing something else without one or both of those things becoming adversely affected. That's a simple fact of life.

Some microcontrollers have specific on-chip hardware which can make it possible to do flawless servo control but like most controllers in the home-hobbyist market place the PICAXE does not. It is possible to work round limitations and problems with careful design and in particular cases but there is no general case, universal panacea, other than by using a dedicated servo control such as the Rev-Ed AXE031 21 Channel Servo controller.

In general though, where servo control is satisfactory when delivered by a PICAXE, it would most likely usually be easier and better to control all servos from a single PICAXE.

Ultimately it all comes down to what else the PICAXE program will be doing. A solution may be better with a separate PICAXE controlling servos or even one PICAXE per servo, or the best solution may be a dedicated servo controller. So much depends on specifics of a project plus its implementation that it's very hard to give detailed advice.