Olimex Web server with 32-bit PIC32MX795F512 PIC microcontroller with TFT display and 100 MBit Ethernet interface PIC32- PIC32-MAXI-WEB 用户手册

The 10-pin UEXT connectors are typically mounted on Olimex boards. They pack three common 
interfaces in a single connector – UART, I2C and SPI. You can use the UEXT connector to access 
this interfaces easier (via jumper wires, for example). 

You can also connect expansion modules to the UEXT connectors. More on UEXT might be found 
here: 

Pin #

Signal name

1

3.3 V

2

GND

3

TXD1

4

RXD1

5

SCL1

6

SDA1

7

MISO1

8

MOSI1

9

SCK1

10

UEXT1_CS

UEXT2 features other UART, I2C and SPI signals. However there is multiplexing on some of the 
lines which might cause problems if you are trying to use the line on both places.

The I2C data lines (SCL2, SDA2) are used for the built-in the board accelerometer. The SPI clock 
signal AC1TX/SCK3A is used by the SD card connector.

Pin #

Signal name

1

3.3 V

2

GND

3

U2TX

4

U2RX

5

SCL2

6

SDA2

7

MISO3A

8

MOSI3A

9

AC1TX/SCK3A

10

UEXT2_CS

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