Raspberry Pi Pico vs STM32 BlackPill for MicroPython: Full Comparison Guide

The Hardware, Briefly

The Pico runs on the RP2040 — a dual-core Cortex-M0+ chip running up to 133 MHz with 264 KB of RAM and 2 MB of external flash. No FPU, 26 GPIO pins, three ADC channels.

The STM32 BlackPill (the F411 variant, which is the common one) runs a single Cortex-M4F core at up to 100 MHz, with 128 KB RAM and 512 KB of internal flash. It has a hardware FPU, 30 GPIO pins, and more than 10 ADC channels.

On paper the Pico has more RAM and two cores, while the BlackPill has a stronger single core and a proper floating-point unit. That difference matters more than you might expect, and we will get to it.

	Raspberry Pi Pico	STM32 BlackPill (F411)
Core 1	Dual Cortex-M0+ @ 133 MHz	Single Cortex-M4F @ 100 MHz
RAM 2	264 KB	128 KB
Flash 3	2 MB external	512 KB internal
FPU 4	No	Yes
GPIO 5	26	30
ADC channels	3	10+
Price	~$4	~$3–5

1. Pico has hardware multi-threading capability.
2. Pico has more than double the RAM size.
3. Pico has bigger flash size, but needs more space and wiring on the PCB, so for projects with space limitations STM32 BlackPill is more useful.
4. Some STM32 models have a hardware FPU (Floating Point Unit), typically Cortex-M4F or M7 cores. STM32F4 with FPU: ~1 cycle per float operation while Pico (M0+): ~20-40 cycles per float operation (software emulation).
5. The PIO is one of the Pico’s most innovative features and a key reason developers choose it for interfacing projects. Pico has dedicated PIO hardware — 2 PIO blocks, each with 4 state machines that can create custom protocols (WS2812, DVI, VGA, custom serial) without CPU overhead. On the other hand, STM32 has no PIO equivalent and uses dedicated peripherals instead: UART, SPI, I2C, timers, DMA.

Getting MicroPython Running

This is where the Pico genuinely wins, and it is not close. With the Pico, you hold the BOOTSEL button, plug it into your computer, and it shows up as a USB drive. You drag the .uf2 firmware file onto it. Done. REPL is ready in under a minute. I have done this on Windows, Linux, and macOS without a single problem.

The BlackPill requires downloading a .dfu or .hex file, putting the board into DFU mode by holding BOOT0 while plugging in, and then flashing it with either STM32CubeProgrammer or dfu-util from the command line. It works, but it is more steps and more things that can go wrong, especially on Windows where drivers sometimes need manual installation.

If you are new to this, start with the Pico just to avoid the setup friction.

MicroPython Features Side by Side

Feature	Pico	STM32 BlackPill
REPL over USB	Yes	Yes
Dual-core / _thread	True dual-core	Single-core only
PIO	Yes (unique to RP2040)	No
Hardware FPU	No	Yes
Timers	4	11
UART	2	3
SPI	2	5
I2C	2	3
PWM channels	16	24
Low-power modes	Basic sleep	Deep sleep + standby
Internal RTC	No	Yes
CAN bus	No	Some variants

The BlackPill has more peripherals in almost every category. If you are building something that needs five SPI buses or eleven timers, you probably already know why that matters.

Performance: Where It Gets Interesting

For most MicroPython projects — blinking LEDs, reading sensors, driving a small display — both boards feel about the same. But once you start doing any serious math, the difference is noticeable.

The STM32F411 has a hardware FPU, and MicroPython actually uses it. A tight loop doing math.sin and math.sqrt calls runs roughly 40–50% faster on the BlackPill than on the Pico. For DSP work, sensor fusion, or anything involving a lot of float calculations, that is a real advantage.

import math, time

start = time.ticks_ms()
for i in range(100000):
    x = math.sin(i * 0.001) + math.sqrt(i + 1)
elapsed = time.ticks_diff(time.ticks_ms(), start)
print(f"Elapsed: {elapsed} ms")
# STM32F411: ~180 ms
# RP2040:    ~310 ms

On the other hand, the Pico has two cores. You can run genuinely parallel Python threads — one core handling communication, another doing computation — and they actually run at the same time. On the BlackPill, _thread is cooperative on a single core, not true parallelism.

Which of these matters to you depends entirely on what you are building.

PIO: The Pico’s Unusual Advantage

The RP2040 has something called PIO — Programmable I/O — which lets you run small state machine programs in hardware, completely independent of the CPU. It sounds technical, but the practical result is that you can implement custom communication protocols at hardware speed without worrying about timing in Python.

The most obvious use case is WS2812 (NeoPixel) LEDs. Driving them requires precise microsecond timing that Python loops simply cannot guarantee. On the Pico, the MicroPython firmware includes a PIO-based driver and it just works. On the STM32, you typically have to use SPI or DMA tricks, which are harder to set up in MicroPython and less reliable.

PIO also makes things like custom one-wire protocols, IR remotes, or exact frequency generation much more manageable. There is nothing equivalent on the STM32 side.

Low Power and the RTC

If you are building something battery-powered, the BlackPill has a real advantage here. It supports deep sleep and standby modes, and it has a built-in RTC that keeps time even when the main MCU is powered down. You can do things like wake on a schedule, which matters a lot for sensor nodes or data loggers.

import pyb

rtc = pyb.RTC()
rtc.datetime((2024, 1, 15, 1, 8, 0, 0, 0))
rtc.wakeup(10000)  # wake after 10 seconds
pyb.standby()

The Pico does have sleep modes, but they are more basic, and there is no hardware RTC. If you need timekeeping, you will need an external module like a DS3231. That adds cost and complexity.

Community and Documentation

The Pico has better MicroPython-specific documentation than almost anything else in this price range. The official docs are clear, the examples are plentiful, and there are beginner tutorials for nearly every common use case. The community has grown quickly, and most MicroPython library authors test on it.

The STM32 community is large and experienced, but it is heavily C-focused. MicroPython resources for the BlackPill exist, but they are scattered and sometimes outdated. If you run into a weird issue with a specific peripheral in MicroPython on the STM32, you might spend a while searching before finding an answer.

Tooling

Both boards work fine with Thonny, VS Code with Pymakr, and mpremote. Thonny makes the Pico especially painless — it detects it automatically and handles firmware installation through the GUI. For the BlackPill, expect a bit more manual setup.

So Which One? (Raspberry Pi Pico vs STM32 BlackPill)

The Pico makes more sense if:

• You are learning MicroPython and want the path of least resistance
• You are working with NeoPixels or anything that needs precise timing
• You want to use both cores for genuinely parallel tasks
• You want good documentation and community support

The BlackPill makes more sense if:

• You are doing math-heavy work and need the FPU
• You are building something battery-powered and need deep sleep or the RTC
• You need more peripheral buses (SPI, UART, I2C, timers)
• You are already in the STM32 ecosystem or plan to move to C/C++ later

Final Thoughts

Honestly, if you are just getting started with MicroPython and do not have a specific reason to use the BlackPill, the Pico is the easier choice. The setup is simpler, the docs are better, and PIO is genuinely useful once you discover it.

But the BlackPill is not a worse board — it is a different one. The FPU, the RTC, the deep sleep modes, and the peripheral count are real advantages in the right context. If your project calls for any of those, the extra setup effort is worth it.

They are both good boards for $4. The question is just which set of tradeoffs fits what you are actually building.

Disclaimer

The information and comparisons provided in this article are based on my personal experience and research. While I strive for accuracy, technical specifications and software support may change over time. Please verify details from official sources before making purchasing decisions. Your project requirements may differ from the scenarios discussed here.

For the most accurate information, you can refer to the manufacturers’ websites.

STMicroelectronics

Raspberry pi

FAQ

Can I run the same MicroPython code on both boards?

Mostly, yes. Core Python features and common libraries work the same way. The differences show up when you use hardware-specific features like PIO on the Pico or the RTC on the STM32. Pin numbers and peripheral assignments will also differ, so you will need to adjust those.

Which board is better for absolute beginners?

The Pico. Setup is simpler, documentation is clearer, and the community is more active around MicroPython specifically. You will spend less time troubleshooting and more time learning.

Does the STM32 BlackPill support MicroPython out of the box?

No. You need to flash MicroPython firmware onto it first. The process is not difficult, but it is an extra step compared to the Pico.

Is the Pico’s dual-core actually useful in MicroPython?

Yes, if your project benefits from parallel execution. For example, one core can handle sensor polling or communication while the other processes data or updates a display. It is not magic, but it does give you real parallelism that single-core boards cannot match.

What is PIO and do I actually need it?

PIO (Programmable I/O) is a hardware feature unique to the RP2040 that runs custom protocols at hardware speed. You need it if you are working with timing-sensitive devices like NeoPixels, IR remotes, or custom communication protocols. For basic GPIO, sensors, and displays, you probably do not need it.

Is the STM32 BlackPill really better for battery use?

Yes. It has proper deep sleep and standby modes, plus a built-in RTC for scheduled wakeups. The Pico has basic sleep, but it draws more power and has no hardware RTC. If low power is critical, the BlackPill is the better choice.

Which board has better long-term MicroPython support?

Hard to say for certain, but the Pico currently has stronger momentum in the MicroPython community. The RP2040 is officially supported by the MicroPython project, and Raspberry Pi actively promotes it. STM32 support exists and is solid, but it gets less attention.

Do both boards work with the same IDE?

Yes. Thonny, VS Code with Pymakr, and mpremote all work with both boards. Thonny is slightly easier with the Pico because it auto-detects it, but both boards are well-supported.

Is the STM32F411 the only BlackPill option?

No. There are other variants like the F401 (cheaper, less RAM) and the F411CE (more flash). The F411 is the most common and offers the best balance of features and price for MicroPython work.

Which board is better if I plan to move to C/C++ later?

The STM32 BlackPill. The STM32 ecosystem has mature C/C++ toolchains, extensive HAL libraries, and widespread industry use. Moving from MicroPython to C on an STM32 is a common path. The RP2040 has good C/C++ support too, but the STM32 ecosystem is larger and more established.

 

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