User Manual

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User Manual (1.3) OpenTracker 2 21
Internal I/O
The Internal I/O 20-pin Expansion connector is a standard 2.54mm Pin header which is not populated.
It features the following pinout:
 1 x SPI
 2 x UART
 1 x I2C
 Analog
 PWM
 GPIO
 (nReset)
 (Erase)
 3.3V
 4V
 VIN
 GND
PLEASE NOTE: IMPORTANT NOTE!
The I/O voltage levels are not 5V tolerant!
Only use 3.3V levels!
The internal I/O are left for custom Expansions done by the user to add functionalities used in special
applications.
Schematic