ST Micro produced a great new chip! And then they packaged it inside a 9x9 0.5mm BGA… I tried to produce a PCB for it, but the limits were too great (tiny?) for OSHPark.

And then ST announced two more packages - and one wasn’t a BGA! It has fewer pins, and isn’t available yet, but this time I could stay within OSHPark’s parameters.

This board gives a breakout for all the GPIO pins (except see below), as well as components for all the special purpose sections. Note, however, the board has not been tested! I will be posting the schematic and BOM soon!

Features

Apart from the actual STM32WLE5C chip, this board has the following features:

• The board is tiny! It is designed to be used standalone, or as a module for a larger board (uploaded soon!).
• The antenna is attached via a U.FL connector.
• The 32 MHz TCXO and support components are included, and wired to PB0 (sorry, not available on a header).
• The PE4259 RF switch and RF signal path components are included.
• Both Low and High TX power paths are supported with solder jumpers JP1 and JP2 - one MUST be chosen and soldered before powering on!
• There’s an FTDI header (with extra pins for Battery), although it only supports 3v3 instead of 5v. Note that the linked device only supports 50mA, which is fine unless you’re using TX/PA High!
• The GPIO breakout is to 2× 17-pin 0.05" headers, for GPIOs and special pins:
  • Port A is on its own header, assigned to the correct pin numbers (starting at pin 0 ). There are also jumpers to connect to the FTDI RxD and TxD;
  • Ports B and C are on a second header, also assigned to the correct pin numbers - they coincidentally(?) interleave!
  • Special purpose pins are brought out, and are next to relevant pins for easy jumpering:
    • BOOT0 is next to GND (recommended) and 3v3 ;
    • Batt is available for the Real Time Clock;
    • NRST is available, and next to JTRST for jumpering if desired (not necessary);
    • VDDA is next to 3v3 , or can be connected to a separate supply if desired;
    • PC14 and PC15 are brought out directly - but have PTH footprints for a 32.768kHz crystal and capacitors if desired (note that the long trace lengths will affect the capacitance required);
    • AntSw CTRL for the PE4259 is available - connect to any GPIO.
  • JTAG / SWD is brought out to a CS10 CoreSight connector - SMD, PTH and Pogo footprints are overlaid. Thus the board can:
    • Be programmed standalone by Pogo;
    • Have an SMD or PTH connector soldered on for development work;
    • Be fitted to a larger breakout board, with (more usable) 0.1" headers and STLink serial programmer.