PWM Hardware + Software
Copy the unzipped 'arm5_no_packs' to your sdk 12.2.0 folder at the following path:
nRF5_SDK_12.2.0_f012efa \examples\peripheral\pwm_library\pca10040\blank\arm5_no_packs
This program uses 12 Hardware pwm outputs and 8 Software pwm outputs on nRF52832, you can modify the values in the array for hardware pwm to vary the duty cycle. This program basically works as an led chaser example with 16 different pwm on 16 different leds