26
10.4 Analog Inputs (A/D Converter)
PiGear Nano has four analog inputs:
PiGear Nano uses chip MCP3424 to provide four-channel, low-noise, high accuracy A/D converter
with up to 18-bit resolution. The A/D converter talks to Raspberry Pi Compute Module 4 via the I2C-6
interface.
As shown in the schematic above, each channel has a voltage divider and a voltage follower before
feeding to MCP3424. Because MCP3424 uses 2.048V internal voltage reference, each channel can
directly measure up to 11.6V.
Remarks: analog input can directly apply up to 11.6V, and needs to have common ground with
PiGear Nano.
MCP3424 has on-board Programmable Gain Amplifier (PGA). You can select the PGA gain of x1, x2,
x4, or x8 before the analog-to-digital conversion takes place. This allows the MCP3424 devices to
convert a very weak input signal with high resolution.
The resolution of ADC is configurable, and different resolution has different LSB, data rate and range
of code. Please see the table below for more details.
Summary of Contents for PiGear Nano
Page 5: ...2...
