Why Servo and PWM Motors Don’t Work Together on Arduino: If you’ve tried running both a servo and a PWM-controlled motor on the same Arduino, you may have noticed an issue: they don’t always work well together. This is a common problem that many Arduino users face, and it stems from a conflict in how the Arduino handles timing for PWM (Pulse Width Modulation) and servo control. Let’s dive into why this happens and how you can work around it.
Understanding PWM and Servo Control on Arduino
To understand the conflict, it’s essential to know how Arduino generates PWM signals for different devices. Arduino boards use timers to manage PWM outputs, which are essential for controlling motor speed and position accurately. Each timer operates independently, and specific pins on the Arduino are linked to certain timers. For instance:
- Timer 0: Controls pins 5 and 6
- Timer 1: Controls pins 9 and 10
- Timer 2: Controls pins 3 and 11 (on many boards)
The Servo library in Arduino relies on Timer 1 to produce the necessary pulse width signals for controlling servo motors. However, when you try to use PWM on pins connected to Timer 1 (like pins 9 and 10) at the same time, you’ll encounter issues. This conflict arises because the Servo library takes over Timer 1, which interferes with the PWM outputs on those pins.
Why the Conflict Happens
When you attach a servo to the Arduino using the Servo library, the library uses Timer 1 to generate precise timing signals required for servo movement. Since Timer 1 is now dedicated to servo control, it can no longer perform regular PWM tasks on pins 9 and 10. As a result, any motors or LEDs connected to these pins won’t receive proper PWM signals, leading to erratic behavior or a complete stop in function.
Which Pins to Use Instead
To resolve this issue, use other pins not tied to Timer 1 if you need PWM control and servo operation simultaneously. Here are the options:
- For PWM Motor Control: Use pins linked to other timers, such as pins 3, 5, 6, and 11. These pins utilize Timer 0 and Timer 2, which are unaffected by the Servo library.
- For Servo Control: Stick with the Servo library on Timer 1 (pins 9 or 10) or try using other servo libraries that can operate on different timers if you need both functionalities on the same pins.
By carefully choosing which pins to connect your devices to, you can effectively work around the timer conflicts.
Other Solutions to Consider
If you need to control multiple servos and motors simultaneously and are running into timer limitations, you could also:
- Use an External PWM Controller: External controllers like the PCA9685 can offload PWM control from the Arduino, leaving timers free.
- Explore Servo Control Alternatives: Libraries like ServoTimer2 can use Timer 2, allowing you to use Timer 1 for other PWM tasks.
- Upgrade to a More Advanced Microcontroller: Some advanced boards provide additional timers or dedicated PWM channels that make simultaneous control easier.
Conclusion
https://eleobo.com/complete-guide-to-setting-up-flutter-development-on-windows/Why Servo and PWM Motors Don’t Work Together on Arduino: Understanding Arduino’s timers and PWM control is key when working with servos and motors. By strategically choosing your pins and considering alternative solutions, you can avoid timer conflicts and ensure smooth operation for both your servo and PWM-controlled motors. With a few adjustments, you’ll be able to create reliable, simultaneous control for multiple components in your Arduino projects.
