Quickstart Guide
Pi-oT 2 Precision Series
Analog Inputs
The MCP3208 powered inputs communicate
with the Raspberry Pi via the SPI 0 channel.
No. of Inputs
8
Resolution
12 Bit
Voltage Range
0-5 V
Common
AGND
Sampling Rate
100 ksps
Galvanic isolation
None
RS485
The SN65HVD72 powered port converts
RS485 signals directly to serial logic, allowing
the Raspberry Pi to communicate with
standard RS485 devices via pins 14 and 15
(BCM).
Surge Protection
≥500
-V surge
transients
Termination R.
0 Ohm
Bias R.
0 Ohm
Galvanic Isolation
None
Analog Inputs:
The 8x 0-5V analog inputs interface to
the Raspberry Pi via the SPI 0 channel. With a
resolution of 12 Bits, the MCP3208 chip be
best used with the
gpiozero
Python library.
The MCP3208 IC is also capable of operating
in differential mode. In this mode one channel
is read relative to the value of a second
channel. For more information, refer to the
gpiozero
documentation or the MCP3208
datasheet.
Note: The AGND pin and GND are connected
via a 40 Ohm resistor internal to the MCP3208
IC. The best practice is to operate the Module
and sensor on the same ground plane.
RS485 Terminal:
The single RS485 terminal is
connected to the Raspberry Pi TX and RX
pins. The circuitry converts the RS485 level
signals to standard serial level in order for the
Raspberry Pi to read it. Open-source Python
Libraries such as
pyserial
or
minimalmodbus
work best for interpreting the signals.
In order for the Module to be used as a
Master on an RS485 bus, termination or bias
resistors are not included in the on-board
circuit, and thus may need to be implemented
elsewhere on the bus.