User manual

LPC3250 Developer’s Kit v2 - User’s Guide

Page 27

4.14 SP8: NXP/Jennic RF Module Interface

There are pads on the backside of the OEM Base Board for soldering a JN5148 NXP (former Jennic)

RF module. These pads are opposite of the SD/MMC memory card interface connector. There is also

provision on the board for programming the RF module. This is done via 6-pos pin list (J31) where a

FTDI programming cable is connected (TTL to USB Serial Converter cable, TTL-232R-3V3, see for

example Digikey: 768-1015-ND). During programming, multiplexor U29 and U30 connects the UART

channel directly to the programming cable, via J31. The RF-module can be reset via SW1. Program

mode is entered by pressing SW9 during (and shortly after) reset.

Note that the UART channel is not directly connected to a UART channel on the LPC3250. It is

multiplexed with other UART channels, see section 4.15 for details. Also note that the Serial Expansion

Connector (see section 4.13 ) and the RF-module share the same UART channel. Once the RF

module is soldered, the Serial Expansion Connector cannot be used for UART communication.

See picture below for locating the relevant components on the board. See also the table for signal

connection.

Figure 13 – RF Module

Signals

LPC3250

SIE_UART_RXD

U1_RX, UART#1 is used

SIE_UART_TXD

U1_TX, UART#1 is used

RF Module on

backside

RF-Program Button

SW9

Reset button

SW1

RF-Program Connector

J31