Nebusens n-Core Sirius A Device, Руководство пользователя

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7
Sirius A User Manual
5.3. ADC
Sirius A device has three analog-to-digital converters. Two
of them are accessible from the block E2. ADC_1 and
ADC_2 are for general purposes (pins 12 and 13). ADC_0 is
connected directly to DC-IN (pin 18), allowing the
monitoring of the voltage used to power the device.
The reference voltage of the microcontroller is 1.25V. The
voltage range for ADC_X
external
input is from 0V to 3.75V.
Next, it is shown the connections of analog-to-digital
converters accessible from outside in the block E2.
This type of connection implies a difference between
the voltage supplied to the external ADC input
(ADC_X
external
) and the voltage registered by the
microcontroller in the internal ADC input
(ADC_X
internal
). The relation between both is given by
the expression:
𝑨𝑫𝑪𝑿
𝒊𝒏𝒕𝒆𝒓𝒏𝒂𝒍
=
𝑨𝑫𝑪_𝑿
𝒆𝒙𝒕𝒆𝒓𝒏𝒂𝒍
𝟑
A similar behavior is observed for the analog-to-digital converter (ADC_0)
connected to the DC-IN power supply. Therefore, the relation between the
power supply voltage and the voltage read at ADC_0 can be calculated as:
𝑨𝑫𝑪𝟎
𝒊𝒏𝒕𝒆𝒓𝒏𝒂𝒍
=
𝑽𝑪𝑪_𝑰𝑵
𝟏𝟏
IMPORTANT NOTE: In order to use the GPI is necessary
that reference pins (GND) of both the Sirius A device
(block E2, pins 6 and 7) and the input device (for
example, a sensor) are connected to each other.
IMPORTANT NOTE: In order to use the ADC is necessary
that reference pins (GND) of both the Sirius A device
(block E2, pin 14) and the input device (for example, a
sensor) are connected to each other.