Connecting Addtional I/O onto the AVNet IoT Dev Kit

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rsquires's picture
rsquires
Junior(0)

I'm currently trying to find a way to attach 5 additional I/O devices to the ATT dev kit. Those being:

  • One small text-basd LCD display.
    • Connected via any type of serial, I2C, or SPI interface.
  • One ultrasonic distance sensor. This requires two GPIO pins.
    • One GPIO output.
    • One GPIO input with timer attached capable of measuring the width of a TTL pulse (5V) possibly as short as 100uS (500 uS is more likely the shortest duration we'd need to measure).
  • Three UART-based color sensors.
    • Each one requires a UART interface.

 

While looking through the documentation, I've found the 3.4.1 Shield I/O Assignments page. After reading, does it say that only one UART and one I2C line (PMOD) is available for use? While trying to connect all this I/O, are there PMOD daughter boards with the various serial interfaces that we could connect. What is the most viable option?

kevinkeryk's picture
kevinkeryk
Moderator(0)

Hi rsquires,

I assume you are using the Freedom K64 board that comes with the Starter Kit, correct?

If so, you can still take advantage of the hardware peripherals offered on the Freedom board itself.  There are lots of I/Os available through the dual-row expansion connector on that board that are not run up to the LTE Shield so you may be able to tap into these with some fly wires to prototype up your solution:

http://www.nxp.com/assets/documents/data/en/data-sheets/K64P144M120SF5.pdf

I see 6 UARTs available (we are using one to talk to the WNC M14A2A module on the shield), there are also 3 SPI peripherals (one could be used for your LCD), and plenty of GPIO available for your ultrasonic sensor.

Another great resource is the hardware guide for the Freedom K64 board, check out Section 16-Input/output connectors here.

http://www.nxp.com/assets/documents/data/en/user-guides/FRDMK64FUG.pdf

Best Regards,

-Kevin

LightCollector's picture
LightCollector
Moderator(20)

Just to be clear the I/O's are 3.3V on the K64F not 5V, so depending upon whether an input or output and the speed of interface you might have to use level translators as well.

 

2 UARTs are used by the system, 1 for the M14A2A and 1 for the K64F serial debug (UART0).  There are 3 or 4 output pins also used to reset, power up and control the level translators for the M14A2A.  The M14A2A is 1.8V and requires the level translators to interoperate with the K64F 3.3V.

 

The aurduino pins all pass through to the top of the 14A2A so it should be easy to jumper into the desired signals.

 

Best regards