GD32F103RET6 PWM Output Not Working_ Here's Why

GD32F103RET6 PWM Output Not Working? Here's Why

GD32F103RET6 PWM Output Not Working? Here's Why

If you’re encountering issues with the PWM (Pulse Width Modulation) output on the GD32F103RET6 microcontroller, it can be frustrating. However, understanding the possible reasons behind the problem can help you troubleshoot and get everything working smoothly. In this guide, we'll walk you through the likely causes of PWM output failure and provide step-by-step solutions to fix the issue.

Common Causes of PWM Output Failure

Incorrect Timer Configuration PWM on the GD32F103RET6 is generated using timers, and an incorrect configuration of these timers can prevent the PWM output from working. Ensure that the timer is properly set to PWM mode and that it’s correctly initialized.

Incorrect Pin Assignment Each PWM output is linked to a specific pin on the microcontroller. If the correct pin is not configured or if it is incorrectly mapped in your code, PWM signals will not appear on the intended output.

Peripheral Clock Disabled The GD32F103RET6 has peripherals that require their respective clocks to be enabled before they can work. If the clock to the timer or GPIO port is disabled, the PWM output won't function.

Faulty GPIO Configuration The GPIO pins associated with PWM outputs must be set to the correct alternate function mode. If the GPIO is set to a different mode (e.g., input or analog), the PWM signal will not be transmitted.

Incorrect Frequency or Duty Cycle Settings If the frequency or duty cycle values set in the timer are out of the range that the hardware can handle, the PWM output may not behave as expected or might not output at all.

Improper Timer Interrupt Configuration Some setups require the use of timer interrupts to manage PWM output. If the interrupt is not configured or enabled correctly, the PWM signal may fail to appear.

Step-by-Step Solutions to Fix PWM Output Issues

Step 1: Check Timer Configuration Solution: Verify that the timer is set to PWM mode. In your code, ensure that the timer is initialized with the correct prescaler, auto-reload values, and PWM mode. Here’s an example initialization code: // Example timer setup for PWM on GD32F103RET6 timer_oc_parameter_struct timer_oc_initpara; timer_parameter_struct timer_initpara; rcu_periph_clock_enable(RCU_TIMERx); // Enable clock for the timer timer_initpara.prescaler = 7199; // Set the prescaler for the timer timer_initpara.alignedmode = TIMER_COUNTER_EDGE; timer_initpara.counterdirection = TIMER_COUNTER_UP; timer_initpara.period = 999; // PWM frequency timer_initpara.clockdivision = TIMER_CKDIV_DIV1; timer_initpara.repetitioncounter = 0; timer_init(TIMERx, &timer_initpara); // Initialize the timer // PWM Output channel setup timer_oc_initpara.outputstate = TIMER_CCX_ENABLE; timer_oc_initpara.outputnstate = TIMER_CCXN_DISABLE; timer_oc_initpara.ocpolarity = TIMER_OC_POLARITY_HIGH; timer_oc_initpara.ocnpolarity = TIMER_OCNPOLARITY_HIGH; timer_oc_initpara.ocidlestate = TIMER_OC_IDLE_STATE_LOW; timer_oc_initpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW; timer_channel_output_config(TIMERx, TIMER_OC_CHANNELx, &timer_oc_initpara); Step 2: Ensure Proper Pin Configuration Solution: Double-check the GPIO pin configuration for the PWM output. The pin must be set to its alternate function mode that corresponds to the PWM output. For example: gpio_init(GPIOB, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_6); // Example for GPIOB Pin 6

If you're using another GPIO pin, ensure that it’s assigned to the correct PWM function.

Step 3: Enable Peripheral Clocks Solution: Ensure that the clock for both the timer and GPIO peripherals is enabled. Without the clock, the peripherals cannot function. Use the following code to enable the necessary clocks: rcu_periph_clock_enable(RCPU_GPIOB); // Enable clock for GPIOB rcu_periph_clock_enable(RCPU_TIMERx); // Enable clock for TIMERx Step 4: Set Correct Frequency and Duty Cycle Solution: Check your frequency and duty cycle settings. If they are set incorrectly, adjust them within acceptable limits based on the timer’s maximum period. timer_channel_output_pulse_value_config(TIMERx, TIMER_OC_CHANNELx, 500); // Set PWM duty cycle (50%) timer_auto_reload_shadow_enable(TIMERx); // Enable auto-reload shadow register for precise duty cycle setting Step 5: Check Interrupt Configuration (if needed) Solution: If your application requires timer interrupts to manage PWM output, verify that the interrupt is configured and enabled correctly. Here’s an example of enabling a timer interrupt: timer_interrupt_enable(TIMERx, TIMER_INT_UPDATE); // Enable update interrupt for the timer nvic_irq_enable(TIMERx_IRQn, 0, 0); // Enable NVIC interrupt for the timer Step 6: Test and Debug Solution: Once all configurations are set, test the PWM output using an oscilloscope or a logic analyzer. This will allow you to verify that the PWM signal is being generated correctly with the expected frequency and duty cycle. If issues persist, carefully review your timer, GPIO, and clock configurations.

Conclusion

By following the above steps, you can systematically identify and fix common issues with PWM output on the GD32F103RET6. Start by checking the timer and GPIO configurations, ensure the correct clock settings, and verify the frequency and duty cycle values. With patience and careful debugging, you'll have your PWM output working smoothly in no time.