Pololu 0J5840, Руководство пользователя

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trimmer potentiometer when its shorting block is in place.
Note: If you call the Pololu AVR library’s sensor reading functions, the 3pi will drive pin
PC5 high for the duration of the sensor read, and it will then drive pin PC5 low. It does
this even if the PC5 shorting block is removed. If this behavior will interfere with what you
want to connect to PC5, you can modify the library code to initialize the sensors with a
bogus emitter pin (e.g. 20 instead of 19).
If you are willing to give up the LCD, as is required when you use the expansion kit without
cutouts
[https://www.pololu.com/product/978]
, you gain access to several more I/O lines. Removing the
LCD completely frees the three LCD control pins (PB0, PD2, and PD4), and it makes the four LCD
data pins (PB1, PB4, PB5, and PD7) available for limited use. If you do use the LCD data pins, you
must make sure that their alternate functions do not conflict with whatever you connect to them. Pins
PB1, PB4, and PB5 connect to the user pushbuttons, and PD7 connects to the green user LED. It is
important to note that PB4 and PB5 are also programming lines, so you must not connect anything
here that would interfere with programming.
So in summary, pins PD0 and PD1 are completely free digital I/O lines that can be used for general-
purpose I/O or for TTL serial communciation. Pins PC5, ADC6, and ADC7 can be freed from 3pi
hardware by removing their respective shorting blocks. PC5 can be used as an analog input or a digital
I/O, and ADC6 and ADC7 are dedicated analog inputs. Pins PB0, PD2, and PD4 become completely
free digital I/O lines once you remove the LCD, and pins PB1, PB4, PB5, and PD7 are digital I/O lines
that you can use for certain applications if you are careful not to cause conflicts between them and
their alternate functionality.
For more information, please see Section 9 for the 3pi pin assignment tables and Section 5.e for the
3pi schematic diagram.
Pololu 3pi Robot User’s Guide © 2001–2019 Pololu Corporation
10. Expansion Information Page 83 of 85