4d Systems Amazing 3.5" Display Module powered by a PIC32 PICadillo-35T Picadillo-35T Hoja De Datos
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Picadillo-35T
4D SYSTEMS PICadillo-35T Display Module
© 2014 4D SYSTEMS Page 20 of 31 www.4dsystems.com.au
6. GPIO on the PICadillo-35T
GPIO Voltage Levels
6.1.
The PICadillo-35T features a Microchip PIC32
microcontroller, which itself runs off 3.3V.
Typically the Arduino range of development
boards was 5.0V and therefore shields used 5.0V
IO. The concern with development platforms that
run 3.3V logic is whether they can handle 5V input
signals from external devices, and whether the
3.3V logic levels will be high enough to activate a
logic high condition on 5V logic shields.
The PICadillo-35T feature a PIC32 which has 5V
tolerant digital GPIO, which means that 5V logic
can be safely connected to this modules digital
GPIO without any worry of damage to the module.
The analog input pins however are only 3.3V, and
therefore inputs on those pins (AN0 through
AN11, along with RB12) should not have inputs
exceeding 3.3V. That said, the PICadillo-35T
features clamp diodes and current limiting
resistors, which aims to protect the processor
from over voltage conditions, such as 5V logic
inputs. It is therefore safe to use 5V inputs on
these pins, however it should be noted the analog
inputs will only read up to a 3.3V level.
When using this board with 5V shields, it should be
noted that the minimum high level voltage level of
the PIC32 is 2.4V when sourcing 12mA of current.
While some 5V shields/devices will accept this as a
logic high level, some will not. Many 5V logic
devices will however work correctly with 3.3V
logic.
Serial Ports
6.2.
The PICadillo-35T makes available 4 Serial UART
ports of the PIC32 for the User.
UART port 0: Asynchronous serial port.
RX0 and TX0. These pins are connected to the P3
Header and are also connected to the FT232R USB
serial converter. It is possible to use these pins to
connect to an external serial device when not
using the USB serial interface. This uses UART1 on
the PIC32 microcontroller itself.
Name
Chip Pin
IDE Pin
Header
U1RX (RX0)
52
0
P3 Pin16
U1TX (TX0)
53
1
P3 Pin14
UART port 1: Asynchronous serial port.
RX1 and TX1. These pins are connected to the P1
Header. This uses UART4 on the PIC32
microcontroller itself, RD14 and RD15.
Name
Chip Pin
IDE Pin
Header
U4RX (RX1)
47
34
P1 Pin15
U4TX (TX1)
48
8
P1 Pin16
UART port 2: Asynchronous serial port.
RX2 and TX2. These pins are connected to the SPI
Header. This uses UART2 on the PIC32
microcontroller, RF4 and RF5.
Name
Chip Pin
IDE Pin
Header
U2RX (RX2)
49
49
SPI Pin1
U2TX (TX2)
50
51
SPI Pin4
UART port 3: Asynchronous serial port.
RX3 and TX3. These pins are connected to the SPI
Header. This uses UART5 on the PIC32
microcontroller, RF12 and RF13.
Name
Chip Pin
IDE Pin
Header
U5RX (RX3)
40
52
SPI Pin5
U5TX (TX3)
39
50
SPI Pin3