interfacing 7 servos to 8051 microcontroller

[kiez47]

I have a robotic arm with 7 servos and I need to interface them with the 8051 microcontroller. Can anyone tell me pls how to to it. On the internet i found out that I have to create like a shield. Since I want to supply 6V to the servo in order to get maximum torque the custom 'shield' simply supplies Vin to the servos. The issue with hobby servos (especially high torque servos) is that, under load, the current consumption can be pretty high. Most tests performed on the web conclude that the peak draw is around 400mA per servo. Allowing for a little head-room (i.e. 500mA per servo) and the fact i have 7 servos, the power supply needs to be rated at over 3 Amps in order to do the job. So can someone tell me how to do the circuit pls?

 

[BradtheRad]

1.

Each servo takes one output pin of your microcontroller. The control signal consists of a pulse which is between 1 and 2 milliseconds long.

You must program the microcontroller to send the proper length of pulse to each output pin.

2.

Do you need to move all 7 servos simultaneously? Your microcontroller can operate them individually. Therefore you can ensure only 1 or 2 or 3 are moving at a time.

Then your power supply can be smaller and less expensive.

 

[kiez47]

No I don't need all the servos to move at ones. All I need to do is sorting 2 objects in there current pot. All I need to know is if I have to build built a type of circuit as seen on the WEB already and what program to make the servos move since this is my first experience in robotic arms. I saw some designs that have a capacitor connected to each servo. So will I have to created a type of design or I just connect to the 8051 microcontroller. Thanks

 

[BradtheRad]

Diagram (grabbed from the internet):

I saw some designs that have a capacitor connected to each servo.

It was most likely across the supply leads, to filter spikes and whatnot.

The control wire needs a sharply-defined pulse.

This is a popular project (servos and microcontrollers). A search at this forum will turn up several threads on the subject.

 

[kiez47]

I would like to make a servo shield that will be compatable with the 8051 microcontroller, but I cannot seem to find any. Any designs that someone made that work pls? Thanks in advance to all trying to help me.