Hardware Reference
In-Depth Information
■
Note
throughout this text, we'll refer to
3 V
, knowing that it is precisely 3.3 V.
Figure
9-2
is a schematic excerpt of the UART section of the Raspberry Pi. The UART
connections are shown as TXD0 and RXD0.
Figure 9-2.
UART interface
Also when selecting a converter, consider whether you need only the data lines, or
the data lines
and the hardware flow control signals
. Some units support only the RX and
TX lines. For hardware flow control, you'll also want the CTS and DTR signals. A full
RS-232 converter would also include DTR, DSR, and CD signals.
DTE or DCE
When choosing your RS-232 converter, keep in mind that there are two types of serial
connections:
DCE
: Data communications equipment (female connector)
DTE
: Data terminal equipment (male connector)
