I am looking at the A13-OlinuXino WIFI for a project that I am starting. One question about the UEXT. If I were to need two peripherals such as ethernet and an RS485 port, is there a way to implement both of these or is the UEXT a one extension port?
Thanks in advance,
Mike Nycz
UEXT offers 1x SPI port, 1x I2C port and 1x UART port.
You can connect more than one I2C if the addresses are different, but generally only one SPI and/or UART.
If you have WiFi .... why would you need Ethernet?
Check if the RS485 uses any other pine than the UART, maybe it would work OK.
You could always use a USB ethernet and put the RS485 on the UEXT. (Olimex sells an USB ethernet module)
The RS485 connection uses 2 of the SPI lines (SCK #SS) to drive the TX/RX state.
You should be able to use I2C and RS485 at the same time.
The simple solution, if you need to use many UEXT modules, is to buy a UEXTx5 connector, right ?
The UEXTx5 only allows you to plug in modules, it doesn't change anything on the pins. So, you still have 1xSPI, 1xUART and NxI2C. It is a better way to plug things in, though.