Extending number of servos ?

Other Hardware Motors, Mechanics, Power and CNC
1

Today (well, yesterday actually)i received the 4 servos i ordered (no plans, just to play around).
Played a bit with the sweep sketch to test them.
While playing, i saw that the servos stop working whenever the signal wires is disconnected.
They do not return to center or end position, they just stop at the point the last instruction told them to go.
Reconnecting that wire just starts the servo to continue to the point the sketch is running at that moment.

So is it a good idea to switch servo's and command those with just a few lines and extend the total number of servo's this way ?
If not, why not ?
So power would stay connected, and only pin 9 (std pin in the sweep sketch) would be connected to a different servo, perhaps by using a 74hc595.

2

There is a library, that support 12 servos, do you need more?

3

Or 48 servos on the Arduino Mega 2560.

If you disconnect the signal wire, some servos turn into idle state.

If you are going to use an extra chip, why not use a I2C servo controller chip, Adafruit 16-Channel 12-bit PWM/Servo Driver - I2C interface [PCA9685] : ID 815 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits

You could even use an AVR microcontroller (the same microcontroller as on the Arduino board) and use it as I2C slave to control a number of servos.

Or a servo controller board, servo (controller,driver) board -stepper for sale | eBay

4

Thanks guys.
That adafruit solution is interesting, and not too expensive.
I asked because i was just wondering what drawbacks there could be by doing it that way.
And to save pins so you can use your Arduino also for inputs or other outputs.

The other boards that involve an extra controller are way too espensive.

5

I read the tutorial of the Adafruit Servo Driver, it is possible to chain the driver boards to control many more servos.