2 Serial Devices on one board

Read the data sheet for the sensors carefully.

Since you are a beginner, I will provide a little bit of terminology;

1. UART

Universal Asynchronous Receiver/Transmitter.

Also known as a serial port.

2. RS232

Level-shifted (and inverted) UART transmit and receive signals.

If your sensor data sheet states that the signals are logic level, eg., 3.3V signals, then the signals are the output of a UART. If the data sheet states that the signals are RS232, then they are level shifted, and will probably be +/-10V signals. Measure the signals with an oscilloscope and see.

If the signals are UART logic levels, then you can instantiate a pair of UARTs in the FPGA and control the sensors directly.

If the signals are RS232 levels, then you need a level translator, i.e., an RS232 level to logic level translator. The DE2 has a serial port - check the schematic and see if there are enough level translators on the DB9 for either one or both sensors. Sparkfun and other microcontroller online stores will have cheap boards with RS232 level translators and 100-mil header connectors that you can use.

Cheers,

Dave