PN 30005 rev 5
NimbeLink, LLC All Rights Reserved.
20
4.3 Connect other Development Kit to Connector J8
4.3.1
Connector J8 Pin Out and Recommended Ratings
Pin
Name
Direction
Description
Min
Typical
Max
If not used
1
RESET_nIN
Input
Controls HW_SHUTDOWN input on Telit X910
modem, tie low for 800mS to activate.
Internally pulled up to VCC with 57k resistor.
Drive with open collector output. Assert only
in an emergency as the module will not
gracefully exit the cellular network when
asserted.
VREF
No Connection
2
ON_OFF
Input
Modem On/Off signal. Assert low for at least 1
second and then release to activate start
sequence. Drive with open collector output.
Internally pulled up to internal I/O rail with
200k pull up. Do not use any external pull ups.
0
1.8V
Must be
implemented.
3
DIO2
I/O
Programmable GPIO_02 on Telit x910 modem
module
0
1.8V
No connection
4
4V0
Output
This is a regulated power supply from the
baseboard. Other development kit could be
powered from this pin if current draw is
<1Amp.
4.0V
No connection
5
DIO3
I/O
Programmable GPIO_03 on Telit x910 modem
module
0
1.8V
No connection
6
DIN
Input
UART data in, I/O level tied to VREF
VREF-
0.4V
VREF
Must be
implemented
7
ADC1
Input
ADC_IN1 input on Telit x910 modem module
(12bit resolution, <1mV, input resistance
1Mohm)
0
1.2V
No connection
8
GND
Input
Ground Pin
0
Must be
implemented
9
RTS
Input
Modem Request to Send hardware flow
control input
VREF-
0.4V
VREF
Tie to GND
10
DOUT
Output
UART data out, I/O level tied to VREF
<0.55V
VREF x
0.67
Must be
implemented
11
CTS
Output
Modem Clear to Send hardware flow control
output
<0.55V
VREF x
0.67
No connection
12
VREF
Input
Voltage reference for offboard I/O signals. This
signal drives the input voltage side of an
onboard buffer which converts all external I/O
voltage from VREF range to 1.8V range to drive
the onboard Telit x910 modem module
1.65V
1.8V or
3.3V
5.5V
Must be
implemented
13
DTR
Input
Modem Data Terminal Ready input
VREF-
0.4V
VREF
Tie to GND
14
ON/nSLEEP
Output
Signal drives the onboard LED indicating
network status. OFF = Device OFF, Fast blink =
Searching for Network & Not Registered, Slow
Blink = Regsitered with full service,
Permanently on = call is active. See Telit x910
modem manual for additional information.
0
1.8V
No connection
