User manual

Hardware

2.7 UART CONNECTIVITY

The RS-232 Serial port (J10) provides a general purpose serial communication port for

application use. The MAX3232CUE (U4) RS-232 transceiver provides the required

translation level and connects to a UART on the MCU (U2).

2.8 USER LEDS AND SWITCHES

The general purpose LEDs, D3, D4, and D5, are available for application use. The

LEDs are connected to the MCU (U2) output ports. Setting the port high will activate

the LED.

The general purpose push button switches S1, S2, S3, and S4, are available for

application use. All four switches are connected to the MCU input ports. Activating a

switch will cause the port line to pull low.

Note: Switches S2 and S3 are marked on the board as controlling volume;

however, these switches do not control the volume of the codec (U1) DAC

directly. The codec DAC volume is controlled by the on-board device (U2).