The W boards (Pico W, Pico WH, Pico 2 W) add an Infineon CYW43439 radio: 2.4 GHz 802.11n Wi-Fi (WPA3, soft AP with up to four clients) and Bluetooth 5.2 (BLE central and peripheral, plus Classic).
Shared pins you must know about
The radio talks to the RP2040/RP2350 over SPI (up to 33 MHz), and some of those signals double up:
- The SPI clock also drives the VSYS voltage monitor. Reading VSYS (e.g. battery voltage) with the ADC only works when no SPI transaction to the radio is in progress. Coordinate battery readings with the wireless driver instead of reading at arbitrary times.
- The radio's data and IRQ signals share a pin, so interrupt requests can only be checked between SPI transactions. Keep this in mind if you write low-level code that touches these pins.
Antenna
Keep the antenna area free. Metal near or under it significantly reduces signal gain and bandwidth; grounded metal along the sides can help. This matters for enclosures and carrier boards.
Licensing (read before shipping a product)
- The wireless libraries libcyw43 and BTstack are free for non-commercial use.
- Raspberry Pi negotiated a free commercial licence for projects built with wireless Pico boards, or with RP2040 + CYW43439 / RP2350 + CYW43439 designs.
- Other radio combinations are not covered by that grant. The full licence texts are linked from the Raspberry Pi documentation (cyw43-driver
LICENSE.RP, pico_btstackLICENSE.RP).
Build C/C++ wireless projects with -DPICO_BOARD=pico_w / pico2_w so the SDK enables the wireless libraries.