Agreed; RP2040 doesn’t have true timer input-capture like STM32 (no CNT->CCR latch on edge). That criticism is fair.
What Pico/RP2040 projects do instead is use a PIO state machine clocked from the system clock to deterministically timestamp edges (often DMA’d out). It avoids ISR latency and gives cycle-accurate edge timing relative to the MCU clock. It’s not a built-in capture peripheral, but it achieves the same practical result.
If you want a drop-in hardware capture block with filtering and prescalers, STM32 is the better choice. RP2040 trades fixed peripherals for a programmable timing fabric.
alt Hacker News
Agreed; RP2040 doesn’t have true timer input-capture like STM32 (no CNT->CCR latch on edge). That criticism is fair.
What Pico/RP2040 projects do instead is use a PIO state machine clocked from the system clock to deterministically timestamp edges (often DMA’d out). It avoids ISR latency and gives cycle-accurate edge timing relative to the MCU clock. It’s not a built-in capture peripheral, but it achieves the same practical result.
If you want a drop-in hardware capture block with filtering and prescalers, STM32 is the better choice. RP2040 trades fixed peripherals for a programmable timing fabric.