User's Manual

Bluegiga Technologies Oy
Page 10 of 31
2.1 I/O Ports
2.1.1 I/O Configurations
Each I/O port can be configured as an input or output. When configured as input, each I/O port can also be
configured with internal pull-up, pull-down or tri-state. Pull-down or pull-up can only be configured to whole
port, not individual pins. Unused I/O pins should have defined level and not be floating. See the BLE
Configuration Guide for more information about the configuration.
During reset the I/O pins are configured as inputs with pull-ups.
Note: Pins configured as peripheral I/O signals do not have pull-up / -down capability
2.1.2 Reserved I/O’s
The high current driving pins P1_0 and P1_1 are reserved for the internal RF front end control. These pins are
not exposed in BLE121LR and they can’t be used for application purposes.
P1_7 is also used for the RF front end control but as an output it can be used to control the external DCDC for
lowering the peak current drawn from the battery. The function of P1_7 can’t be altered. If external DCD is not
used then P1_7 should be left not connected.
2.2 UART
UART baud rate can be configured up 2 Mbps. See the BLE Configuration Guide for more information.
Following table lists commonly used baud rates for BLE121LR
Baud rate (bps)
Error (%)
2400
0.14
4800
0.14
9600
0.14
14 400
0.03
19 200
0.14
28 800
0.03
38 400
0.14
57 600
0.03
76 800
0.14
115 200
0.03
230 400
0.03
Table 5: Commonly used baud rates for BLE121LR