GESBC-9G20i
User’s
Manual
Version 0.2
Page 14 of 21
20-Sep-13
ZigBee Interface
The GESBC-9G20i Single Board Computer is shipped with socket for XBeeZnet2.5 module from
Digi. The serial data lines connected to the ZigBee interface are RXD1 and TXD1 from the
AT91SAM9G20 processor. The hardware control signals are RTS1 (PB28) and CTS1 (PB29)
from the AT91SAM9G20 processor. The system reset signal NRST is connected to the module
RESET line pin 5.
Optional A/D
The GESBC-9G20i Single Board Computer provides support for optional 12 bit 8 channel A/D.
The A/D is provided by TI ADS7870 which is a 12 bit 8 channel analog to digital converter with
programmable gain amplifier. It also provides 4 programmable digital I/O. The maximum
sampling rate of ADS7870 is 100 ksps. The 8 single ended analog inputs can be also configured as
4 pairs of differential input channels. The optional A/D interface is provided via a 2x8 2.54mm
header. The signal designation is listed in the following table.
Table 6 J12 Optional A/D
Pin Number
Signal Name
Pin Number
Signal Name
1 AIN0
2 AIN1
3 AIN2
4 AIN3
5 AIN4
6 AIN5
7 AIN6
8 AIN7
9 AGND
10
AGND
11 DIO0
12 DIO1
13 DIO2
14 DIO3
15 GND
16 GND
JTAG
The GESBC-9G20i Single Board Computer is shipped with a 10 pin connector that provides JTAG
debug signals for the CPU. The JTAG provides the user with the ability to debug system level
programs. The signal designation is listed in the following table.
Table 7 J20 JTAG Connector
Pin Number
Signal Name
Pin Number
Signal Name
1 3.3V
2 3.3V
3 NTRST
4 TDI
5 TMS
6 TCK
7 RTCK
8 TDO
9 GND
10
GND
