emSTAMP Helium (Rev3)
20/23
Pin
Signal
1
GND
2
n/c
3
n/c
4
RX
(DEBUG_RXD)
5
TX
(DEBUG_TXD)
6
n/c
6.9
Reset & Wakeup
The WAKEUP (WKUP) Signal is directly connected to the processor. The signal uses a active-
low logic. An external button is added on the SBC developer board to use the WAKE function.
The RESETIN# signal is connected to a reset circuit on the Helium module and is asserted
with lo
gic “0”. An external button is added on the SBC developer board
to use the RESET
function.
6.10
Backup Battery
By the V_BAK Signal, the processor on the Helium module can be supplied by an external
battery. An external battery holder is added on the SBC developer board.
6.11
Base LEDs
With two PWM signals (PA31 and PB1), two status indication LEDs can be driven from the
processor on the Helium module. The LEDs are added on the SBC developer board.
6.12
Power Supply
The Helium SBC developer board has a power supply input at power socket. The base board
should be supplied with +5 V (± 5%) with a maximum power consumption of
t.b.d.
W. The
voltage is protected from reverse polarity.
