I'm building a bipedal robot and I'm using 7,4V servo motors that can consume 3.9A of current (Feetech FT5835M) and RPi4B, how can I control these servos? I'm thinking about using Adafruit 2327 HAT but I read that it can only operate at 5V, what should I do to control my servos? manufacturer's site I bought them here
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1research how the servo is controlled ... hint: 7,4 V 3.9 A is irrelevant– jsotolaApr 8, 2022 at 22:01
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FeeTech is a good choice: penzu.com/p/cf035eca– tlfong01Apr 9, 2022 at 2:27
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FeeTech LX Servos operate at 11V and can do 20kg.– tlfong01Apr 9, 2022 at 2:37
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Link to servo technical specs?– joanApr 9, 2022 at 6:14
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@joan manufacturer's site– BocianApr 9, 2022 at 11:32
1 Answer
Use an external power supply for the servo.
Connect a wire between the external power supply ground (-ve terminal) and a Pi ground. This ensures that the servo and the Pi have a common voltage reference.
Connect a wire between a Pi GPIO and the control line of the servo. The servo detailed specs says that the control line needs between 0V and 0.45V for low and between 2V and 5V for high. As the Pi outputs 0V for low and 3.3V for high the servo will work okay.
The servo you link appears to be a continuous rotation servo rather than a standard servo. Is that intended?
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I contacted the shop for information about this servo and I'm waiting for the response. Isn't it possible to use a continuous rotation servo motor just as a standard servo motor? Can't I just translate rotation speed to an angle?– BocianApr 9, 2022 at 12:39
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No. A standard servo goes to the commanded angle and stops (the angle is set by the pulse width). A continuous rotation servo spins at the commanded speed and direction (the speed is set in proportion to the distance of the pulse width from 1500 µs, the direction according to whether the pulse width is less than or greater than 1500 µs).– joanApr 9, 2022 at 15:17
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I've looked again at the Feetech site and it may just be a case of unclear translation between English and Chinese. Most of the shop listings seem to suggest it's a standard servo, The shop will know.– joanApr 9, 2022 at 15:33