Difference between revisions of "SG90 Servo"
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'''If it does not work, keeps disconnecting, or rebooting the ESP the power is not sufficent and you need a capacitor ot an extra power supply.''' | '''If it does not work, keeps disconnecting, or rebooting the ESP the power is not sufficent and you need a capacitor ot an extra power supply.''' | ||
| − | See the video for details how to do this. | + | See the last section below ([[SG90 Servo#Power Issues]]) and the video for details how to do this. |
= Schematic - Connecting the SG90 = | = Schematic - Connecting the SG90 = | ||
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= Power Issues = | = Power Issues = | ||
When connecting the servo to the ESP32 or ESP8266 it may not work at all, may restart at random times, or may move to a wrong angle. This is typically a power issue. The ESP-board is and the USB-output of the computer does not provide enough power. | When connecting the servo to the ESP32 or ESP8266 it may not work at all, may restart at random times, or may move to a wrong angle. This is typically a power issue. The ESP-board is and the USB-output of the computer does not provide enough power. | ||
| − | There are two fixes: adding a big capacitor (e.g. 2000 uF) or adding an external power source. The external power source is the better solution. | + | There are two fixes: adding a big capacitor (e.g. electrolytic capacitor [[Elko]] 2000 uF) or adding an external power source (e.g. [[USB-Power]]). The external power source is the better solution. |
Have a look at the video for details. | Have a look at the video for details. | ||
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[[File:PowerUSB-setup.JPG|400px]] | [[File:PowerUSB-setup.JPG|400px]] | ||
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| + | [[Category:Actuators]] | ||
Latest revision as of 09:32, 14 June 2024
Contents
IMPORTANT[edit]
In many computers the current is not enough to drive the servo!!!
If it does not work, keeps disconnecting, or rebooting the ESP the power is not sufficent and you need a capacitor ot an extra power supply.
See the last section below (SG90 Servo#Power Issues) and the video for details how to do this.
Schematic - Connecting the SG90[edit]
Code Examples ESP8266[edit]
Basic control[edit]
Assuming the servo is connected to Pin 5.
1 from machine import Pin,PWM
2 from time import sleep
3
4 servoPin = Pin(5, Pin.OUT)
5 pwm = PWM(servoPin, freq=50)
6 pwm.deinit() # workaround to reset PWM
7 pwm = PWM(servoPin, freq=50)
8
9 val = 50
10
11 while True:
12 pwm.duty(val)
13 val = val + 1
14 if val>100:
15 val = 50
16 print(val)
17 sleep(0.05)
Controlling the servo with a Poti[edit]
A0 is the analog input with 10 bit resolution. It reads the analog value every second and print it to the console and sets the servo based on the analog input.
1 from machine import Pin, ADC, PWM
2 from time import sleep
3
4 analogPin = ADC(0)
5 servoPin = Pin(5, Pin.OUT)
6 pwm = PWM(servoPin, freq=50)
7 pwm.deinit()
8 pwm = PWM(servoPin, freq=50)
9
10 while True:
11 analogVal = analogPin.read()
12 pwm.duty(int(analogVal/10))
13 print(analogVal)
14 sleep(1)
Related Tutorial Videos[edit]
PWM Output: connecting a servo and and LED[edit]
Power Issues[edit]
When connecting the servo to the ESP32 or ESP8266 it may not work at all, may restart at random times, or may move to a wrong angle. This is typically a power issue. The ESP-board is and the USB-output of the computer does not provide enough power. There are two fixes: adding a big capacitor (e.g. electrolytic capacitor Elko 2000 uF) or adding an external power source (e.g. USB-Power). The external power source is the better solution.
Have a look at the video for details.
Adding a Capacitor[edit]
Connecting an external Power Source[edit]
