ESP32 vs RP2350: how I pick the brain of a project

I keep both ESP32 and RP2350 boards on the bench, and I'm regularly asked which one is "better." The honest answer: they're good at different things. Here's how I decide.

The short version

ESP32: the connected one

The ESP32 family's superpower is the radio. Wi-Fi and Bluetooth on the same die (plus Thread/Zigbee on some newer variants) mean a single module handles compute and connectivity. Pre-certified modules take most of the RF pain away.

The tradeoffs:

• Radio activity creates current spikes and timing jitter you have to design around.
• The classic ESP32 has some quirks: strapping pins that affect boot, input-only pins, and ADC2 being unusable while Wi-Fi is active.
• Power in deep sleep can be excellent, but development boards with USB-serial chips and regulators often hide that.

RP2350: the precise one

The RP2350, the chip in the Raspberry Pi Pico 2, has two Arm Cortex-M33 cores (or two RISC-V cores — you choose at boot), 520 KB of SRAM and Raspberry Pi's PIO blocks: tiny state machines that run their own instructions and toggle pins with cycle-level timing.

PIO is the reason I reach for it. Need an unusual serial protocol, a strange LED timing, or several synchronized outputs with deterministic phase relationships? PIO handles it without the CPU breaking a sweat. The documentation is also unusually clear.

The tradeoffs:

• No built-in radio. You add one (the Pico 2 W pairs it with a separate wireless chip), which means more parts and more design work.
• Fewer pre-certified "everything in one module" options for wireless products.

The five questions that decide

1. Does it need to talk to Wi-Fi or a phone? If yes and nothing else matters much, ESP32.
2. Does it need exact timing on pins? If yes, RP2350 is hard to beat.
3. How is it powered? On battery, measure early. Both can be frugal; neither is frugal by accident.
4. What will the production board look like? Count chips, connectors and certifications, not just dev-board convenience.
5. What does the team already know? Familiarity is a legitimate engineering input.

Using both

Sometimes the answer is both. An RP2350 handles precise I/O and sensing; an ESP32 module acts as the radio and gateway, talking to it over UART or SPI. That split shows up in my mesh and measurement projects, where timing and connectivity are separate jobs.

The meta-lesson

Choosing a microcontroller is a requirements exercise, not a fan-club vote. Write down what the device must do, then pick the part that makes those requirements easiest to meet. The best MCU is the one that leaves you the fewest problems to solve.