OLIMEX© 2014
AVR-T32U4 user's manual
7.5 USB mini connector
Note that the USB is confiugred only as device.
Pin # Signal name
1
+5V
2
D-
3
D+
4
Not connected
5
GND
7.7 Jumper description
All jumpers on AVR-T32U4 are board mounted SMT type. This means you would need to cut or
solder to be able to change the position. You would need basic soldering tools and skills to be able
to change the positions.
7.7.1 Jumper 5V_E
If you close 5V_E then the 3.3V voltage regulator VR1 would be bypassed. 5V from the USB or the
proto powering pins would go directly to the board.
Default state is open.
7.7.2 Jumper R23_E
Controls the SPI SCL 4.7k pull-up resistor. By default the jumper is closed and the resistor is
enabled.
Default position is closed.
7.7.3 Jumper R24_E
Controls the SPI SDA 4.7k pull-up resistor. By default the jumper is closed and the resistor is
enabled.
Default position is closed.
7.7.4 Jumper R25_E
Controls the SPI CS (chip select) 4.7k pull-up resistor. By default the jumper is closed and the
resistor is enabled.
Default state is closed.
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