Software or Hardware for this part of my robot?

Other Hardware Robotics
1

I'm building a robot which will have 8 servo's and two rgb leds. I'm having some trouble with the servo's. I'd like to be able to control speed and range of each servo. I know the Servo library does not support speed but there are other libraries in my searching that use software for this control.

Another option is a servo controller which does it all in hardware. 8 servo's + 2 RGB leds will = 14 PWM signals. This robot will use Bluetooth so communication will be Serial. So I'm kinda confused, at what point is a controller needed? I have a simple pan tilt setup working with 2 of the servo's but they're very jittery and of course the speed issue. I haven't tried the other libraries yet, Im hoping someone has crossed this bridge already and can say what worked for them.

2

Are you using SoftwareSerial for the bluetooth interface? It will disable interrupts for significant periods of time and that causes jitter in the Servo library.

If you can use a Leonardo you can use the hardware serial port (Serial1) for Bluetooth while still using USB (Serial) for upload and debug.

The Arduino MEGA also has several spare hardware serial ports.

3

I'm using the hardware Serial with the Servo library on my Arduino Uno. Haven't yet, but I will try the VarSpeedServo library.