ConnectCore 6UL SBC Pro interfaces
Additional expansion interfaces
ConnectCore 6UL SBC Pro Hardware Reference Manual
36
I/O Expander IRQs
You can configure a subset of the available IOs as interrupt inputs and specifically to configure the
active edge of the interrupt (rising, falling, or both). When one or more IRQs are activated, the I/O
Expander interrupts the main ConnectCore 6UL module through the corresponding IRQ line, signaling
the active IRQs in the IRQ status registers. The IRQ inputs can wake the system from any low power
mode (suspend or power off).
The I/O Expander uses the IOEXP_INT_MCA# line to signal the interrupts to the ConnectCore 6UL
SoM, which means that all enabled IRQs in the I/O Expander will wake up the SoM from a sleep status.
To prevent this, the IRQs should be masked before suspending the module.
See the
I/O Expander GPIO driver documentation
for additional information about how to configure
and access its lines.
Analog to Digital Converter
You can configure a subset of the available IOs as Analog to Digital channels. The index of the MCA ADC
channels corresponds to the index of the IO listed. This means that the ADC channel 3 corresponds to
the IO3 signal, the ADC channel 4 to the IO4, and so on.
The result of the ADC conversion for a given input voltage is inversely proportional to the reference
voltage of the ADC. For the I/O Expander in the ConnectCode 6UL SBC, the reference voltage
corresponds to the 3V3_IOEXP voltage. (Note that it is a different voltage reference than the
ConnectCore 6UL MCA ADCs.) The ADCs provide 12-bit resolution with right-justified, unsigned format
output. They are suitable for low-frequency sampling (under 10 Hz). For higher frequency sampling,
Digi recommends the CPU ADC channels.
See the
I/O Expander software documentation
for additional information about how to configure and
access the I/O Expander ADCs.
Other peripherals
User LED
The I/O Expander controls a LED through line USER_LED1/IO23. You can drive the user LED by
configuring this line as a digital output and setting its value.
XBee Socket
The following table shows the lines of the I/O Expander that are connected to the XBee socket,
allowing more precise control of these modules. However, it is important to note that the actual
behavior depends on the XBee version and how it is configured. Refer to the XBee manual reference
for more details on how these lines behave.
I/O Expander pin
name
Signal name
Pin
direction
Description
IO7
XBEE_RSTN/IO7
Output
Used for controlling the XBee reset line.
IO9
XBEE_SLP_
RQ/IO9
Output
Used for both requesting the XBee to sleep
and waking it.
IO11
XBEE_ON/SLP_
N/IO11
Input
Used for reading the power status of the
XBee.
IO33
XBEE_
IDENT/IO33
Output
Used for commissioning of the XBee.
