LPC11U37 Details

 

The LPC11U37 is footprint and pin superset of the old Parallax BASIC stamp . The board can be used with 5V TTL signals.  It has a total of 40 IO pins available.

BASIC or C programs can be downloaded using the builtin USB connector. MakeItC and BASICtools use the serial connection of the board.  You can load mBed programs by shorting the ATN and GND pins (3 and 4 of the stamp arrangement) which then bring the device up as a disk drive that you can overlay the firmware.bin file.  It can be ordered with an optional JTAG/SW connector so that it can use Keil, IAR, MCUxpresso or other tools.  The board can also be ordered as a JTAG/SW debugger that can connect to other ARM CPUs.

Digital IO connections

Below is a diagram of the pins, note it has been rotated 90 degrees to make it easier to read,
The NXP pins P0.1-31 shown as 1-31 and P1.0-31 as 32-63 below in red.  For convenience the pins can be refered to as SP0-39 as stamp pins by using the definitions in STAMP_PINS.bas and STAMP_PINS.h  (shown in black and green below).
 
Analog pins
There is an A/D converter with an 8 input analog multiplexor. After power on these pins are inputs, when a program calls for an AD input they are converted to analog.
Special purpose pins
 
RESET pin starts the ARM program if the ATN/SP18 (P0.1) pin is high.  If you use ATN/SP18 P0.1 as an input you MUST make sure it is in the high state when RESET is asserted, otherwise your program will NOT start.  RESET can also be defined as a IO, though you must enable it with a specific call.  On power on the RESET pin has an internal pullup and must be high during this time or your program will not start.
 
SOUT and SIN  (SP17-18) are configured as inputs on reset.  They are converted to TTL serial lines (positive true) when BAUD(0) is set.
 
Pins are configured as digital inputs on power on,  SP23 and SP24 are open collector pins, which can be used as IOs or dedicated I2C pins.  The Serial Wire debug pins (SP30 SP35) are converted to inputs by the initial firmware, but can be used by SW/JTAG pins by other tools such as Keil, IAR and MCUxpresso.
 
The LPC11U37 supports a number of dedicated functions.  Those include 1 UARTs, 2 SSP/SPI, 1  I2C, I2S, 2 multi-channel PWMs,timer counter capture and match.
 
Details can be found in NXP's User manual .
 
Memory Map
 
The full schematic can be seen here
The internal 24 stamp pins are on a 0.1" DIP spacing with a 0.6" width. An additional 24 pins are also 0.1" space with a 0.8" width.
 
Part placement