Hobby task
Measure a PWM signal with the Rigol DS1054Z
Task: check whether a microcontroller PWM output is running at the expected frequency and duty cycle before it drives an LED, fan, motor controller or MOSFET gate.
What you need
Use one DS1054Z channel, a standard passive probe, the circuit ground point and the PWM output pin. Start with the probe set correctly and match the probe setting in the oscilloscope channel menu.
How to use the DS1054Z
Connect the probe ground to circuit ground and the probe tip to the PWM output. Set the vertical scale so the high and low levels fit clearly on screen. Adjust the timebase until several PWM cycles are visible, then use edge trigger on the PWM channel to stabilise the waveform.
Use the measurement menu to display frequency and duty cycle. If the signal is unstable, zoom in and check for ringing, slow edges or unexpected noise. The DS1054Z's four channels let you add a second probe to compare the PWM output against the supply rail, enable signal or load response.
What result should you get?
You should see a stable square wave with frequency and duty cycle close to your firmware settings. If the duty cycle is wrong, check timer configuration. If the voltage level is wrong, check pin mode, supply voltage and loading. If the edges look poor, check wiring length, grounding and the driven circuit.
Why the DS1054Z helps
A multimeter may show an average voltage, but the oscilloscope shows the actual switching waveform. That makes PWM faults much easier to diagnose.