Hello, this is arfan from India, I’m a b.tech first year student, I’m making a biped robot using Servos and arduino uno. I want to know maximum how many Servos can I use on a single arduino uno board and Should the pin be a pwm pin even if I’m using servo library. If anyone could help me out on the code to drive 8servos,of which two are continuous rotation Servos using the servo library.
Hi,
You can use quite a bit of servos using the Arduino Servo library. They specify that up to 12 motors can be used on most boards. On some configurations, even more can be used. So, you should be fine with 8.
For continuous rotation servos, simply use the library to write a “position” based on what you want the servo to do. Assuming 1500 us is idle, anything lower will rotate in one direction (increasingly as you get lower, up to maximum speed) and any value higher than 1500 us will make it rotate in the opposite direction. Again, the servomotor will rotate fast as the value increases (gets away from the idle/center value).
With the Servo library, you do not need to use PWM pins specifically.
Please note that as you use more servos, the accuracy of the library may drop / be less responsive as all of it is done using software.
If you find that this does not do all you need, you may want to invest in a dedicated servomotor controller, such as the SSC-32U or others found here.
warning: If you are powering 8 servomotors, make sure to have a secondary power supply for your servo motors VCC/GND connection. The Arduino will most likely not be able to provide enough current for that many motors.
Sincerely,
thank u,i want to use GSM(GSM900) technology for communication purpose using the arduino uno.i want to know the connections and the code to make a voice call, the example sketch supports only the arduino GSM shield ,should i use the GSM library for the GSM 900 .please help me out with the code
Hi,
You can read more about the Arduino GSM library here. They also provide an example of making a voice call here. The function reference for voiceCall() can be found here. They also have a page concerning getting started with the Arduino GSM shield, which should be a good starting point, even if you use a different shield.
You can purchase the official shield (version 2). If you use this shield, don’t forget to obtain an antenna. You can browse our available antennae here.
If you wish to use a different shield, have a look at these.
Sincerely,