No announcement yet.

4DPi-24-HAT and access to UART

  • Filter
  • Time
  • Show
Clear All
new posts

  • 4DPi-24-HAT and access to UART

    I've got an RPi3 with a 24-HAT, fully functional and quite happy with the setup. I'm trying to develop a small onboard display for telemetry for my '80s Ford Mustang. I intend to use Qt5 as the GUI framework and to read sensors over the USB ports and UART. Looking at the schematics provided in the 24-HAT's datasheet it's not clear what is happening with the UART pins on the RPi. Pins 8 and 10 on the RPi are for the UART, but the datasheet schematic shows that they may be hooked up to GPIO 14 and 15. I'm curious whether this means that the UART pins have been usurped by the HAT or if there is a way to use some other unused GPIO pins instead of the UART pins for the purpose they're being used for the HAT. Ultimately, I would like to connect an external GPS receiver to the UART.
    RPi 3 w/24-HAT

  • #2
    Hi Mesozoic,

    Welcome to the forum!

    Based on this:

    TX and RX are on pins 8 and 10, as you said, which is also GPIO14 and GPIO15, which is what is noted in our schematic.
    If you look at the schematic in the Datasheet at the back, there is no use of GPIO14 and GPIO15 other than on the header itself, so these pins are spare for you to use as you wish.
    GPIO22 is the only one I can spot which is being used by the 4DPi-24-HAT, if you opt to use that for backlight control.
    Other than that, the 4DPi-24-HAT is mainly SPI based with I2C for touch.

    Hope that helps