Expansion Board Connector Pinouts

Serial Connector

MiniDIN-8 connector diagram: Image:Minidin-8.png

Serial Null Modem Cable

DB9 signalDB9MiniDIN8 SignalMiniDIN8
RxD 2 3 TxD
TxD 3 5 RxD
RTS 7 2 CTS
CTS 8 6 RTS
GND 5 4 GND

Serial Modem Cable

DB9 signalDB9MiniDIN8MiniDIN8 signal
RxD 2 5 RxD
TxD 3 3 TxD
RTS 7 6 RTS
CTS 8 2 CTS
GND 5 4

GND

UART

Note: Current kernels use ttyS3 (HWUART) for bluetooth. This is available on the BTUART pins by setting GPIO42 and 43 to AF3 - and this is the default configuration. This can be very confusing if you want to use the HWUART for something else! To re-enable HWUART on ttyS3, make bluetooth use ttyS1 (see /etc/default/bluetooth) and then set GPIO42 to AF1 in and GPIO43 to AF2 out. You can then set GPIO48 to AF1 out (HWUART TXD) and GPIO49 to AF1 in (HWUART RXD).

FFUART

FF_CTS
FF_RTS
FF_TXD
FF_RXD
  • Logic level (3.3V) signals
  • Speeds to 230 kbps
  • Normally mapped to ttyS0 in the kernel and Y0 in some schematics
  • FFUART pins are located on the 60-pin Hirose connector
  • Schematic diagram for the FFUART

HWUART

HW_CTS
HW_RTS
HW_TXD
HW_RXD
  • Logic level (3.3V) signals
  • Speeds to 921 kbps
  • Normally mapped to ttyS3 in the kernel and Y1 in some schematics
  • HWUART pins are located on the 60-pin Hirose connector (connex and basix only)
  • Schematic diagram for the HWUARt

STUART

  • Logic level (3.3V) signals
  • Speeds to 230 kbps
  • Normally mapped to ttyS2
  • Schematic diagram for the STUART

BTUART

BT_CTS
BT_RTS
BT_TXD
BT_RXD
BT_NRESET Bluetooth reset (output, active low)
CLK_32 32.768 kHz Clock output
  • Logic level (3.3V) signals
  • BTUART pins are located on the 0-pin Hirose and 24-pin flex ribbon (verdex only) connectors.
  • It is not an exposed interface; mapped to ttyS1 by the kernel and connected physically to the bluetooth module if one is present.
  • BT_NRESET and CLK_32 are for an optional Bluetooth module IC (24-pin flex ribbon only)

NSSP

  • Slave speeds to 13 Mbps
  • Master speeds to 3.6864 Mbps

USB

  • Version 1.1
  • Requires one or two additional GPIO lines for presence or sleep detection

I2C

  • The I2C unit supports a fast mode operation of 400 Kbits/sec and a standard mode of 100 Kbits/sec. Refer to I2C bus specification for details.

Note the I2C on the Gumstix page.

Batteries and power

Gumstix verdex pro motherboards require 3.4V min and max 5V. Using a power supply above 5v generates extra heat. Gumstix uses LDO voltage regulators, and have on-board generation of all voltages required so just plug in the power supply to any of the expansion board power input ports and go. This range covers Li-Ion, Li-polymer, NiMH (3-cells) or any other combination of reasonable unclean battery supplies that provide nominal output around 3.6 - 5.0 V.