OLIMEX© 2017
OLIMEXINO-32U4 user's manual
7.5 USB mini connector
Note that the USB is configured only as device.
Pin #
Signal Name
1
+5V
2
D-
3
D+
4
Not connected
5
GND
7.6 Jumper description
3.3V/5V
This jumper controls whether the board is powered by 3.3Vdc source or 5Vdc. It is provided to
ensure compatibility with both original 5V shields and 3.3V modules.
Important! Changing this jumper also changes the voltage available at pin #1 of UEXT and also the
voltage levels of all data signals available there (UART, SPI, I2C). Most Olimex-manufactured
UEXT modules work at 3.3V – they would get damaged if the jumper is set 3.3V. When using
Olimex MOD- board on this UEXT ensure the jumper is set to 3.3V, else you might damage the
module.
Default position is 2-3 – 5Vdc.
AGND_E
When closed enables analog GND. SMD jumper.
Default state is closed.
FET3_E
When closed connects D8 from Arduino shield connector to FET3 so you can control the power on
the UEXT by software means.
When open D8 becomes GPIO. This is a SMD type of jumper.
Default state is closed.
Page 18 of 28
