Operation Manual

Human-computer interfacing
130
Notes:
GPIO board pins
There are 17 pins available to operate in GPIO mode, configurable as either inputs
or outputs. They carry just one bit of digital data.
High = 3.3V
Low = 0V
Board pin BCM GPIO number
3* 0
5* 1
7 4
8 14
10 15
11 17
12 18
13 21
15 22
Board pin BCM GPIO number
16 23
18 24
19 10
21 9
22 25
23 11
24 8
26 7
* Note that these pins have a 1.8k pull-up resistor on the Raspberry Pi board.
Inter-Integrated Circuit (I²C)
I²C is an interface on which you can connect multiple I²C slave devices.
The Raspberry Pi acts as the master on the bus.
Serial Peripheral Interface (SPI)
SPI is an interface on which you can connect multiple SPI slave devices.
The Raspberry Pi can only act as the master on the bus.
There are five pins available to connect devices to the Raspberry Pi using SPI:
Universal Asynchronous Receiver/Transmitter (UART)
The UART is a serial bus connection. Note that these pins run at 3.3V and the
RS232 specification is for 12V. If you connect this to a RS232 serial device, you
could potentially damage your Raspberry Pi. Please be careful!
Board pin BCM GPIO number Function Description
3* 0 SDA Data
5* 1 SCL Clock
Board pin BCM GPIO number Function Description
19 10 MOSI Master Out, Slave In
21 9 MISO Master In, Slave Out
23 11 SCLK Serial Clock
24 8 CE0 Channel Enable 0. Also known as Slave Select (SS)
26 7 CE1 Channel Enable 1. Also known as Slave Select (SS)
Board pin BCM GPIO number Function Description
8 14 TX Transmit
10 15 RX Receive
Tip...
Please be careful
with the UART
connection!
If you use too
much current
then you could
easily break
something!