User manual

LPC4357 Developer’s Kit - User’s Guide

Page 36

4.22 SP13: UART-to-USB Bridge

There is a UART-to-USB bridge on the board. This is to simplify connection to a PC because serial

ports are not so common any more, especially not on laptops. The USB port also offers the possibility

to power the board. It is USART#0 that is connected to the USB channel. This UART is commonly

used as the console channel for applications. Printf() output is for example typically directed to this

UART channel.

The UART-to-USB bridge is based on the chip FT232RL from FTDI. A driver is typically needed to be

installed on the PC side. The driver creates a virtual COM port on the PC that represents the UART

channel. Any program on the PC can connect to this COM port for communication with the LPC4357

UART channel. There are two LEDs (Transmit – LED38 and Receive – LED37) that signal

communication activity.

It is NOT possible to download code in ISP-UART mode via this interface (like it is with other

OEM boards). The jumpers in JP20 should NOT be inserted. It was not possible to make pinning of

the LPC4357 OEM board compatible with the OEM Base Boards to allow for automatic ISP invocation

and usage of ISP-UART mode. Read section 5.4 for more information about how to download code to

the LPC4357.

See picture below for locating relevant components. The table below lists signal connections.

Figure 23 – UART-to-USB Bridge

Signals

LPC4357

GPIO16_TXD

PF_10, USART0 is used

GPIO17_RXD

PF_11, USART0 is used

USB mini-B Connector

J25

Transmit LED

LED38

Receive LED

LED37

Automatic ISP

JP20

Cannot be used!