PIC Tutorial - RS232 Board
RS232 Board
This
is the RS232 board, it uses a MAX232 5V to RS232 converter chip, this
converts the 0-5V TTL levels at the PIC pins to the +12V/-12V levels used
in RS232 links. As is common with these devices it inverts the data during
the conversion, the PIC USART hardware is designed to take account
of this - but for software serial communications you need to make sure
that you invert both the incoming and outgoing data bits.
The
two closed links on the RC7 and RC6 lines are for connection to the 16F876
board (the 16F876 uses RC6 and RC7 for it's USART connection), and are the
two top wire links shown on the top view of the board below. The two open
links on the RC1 and RC2 lines are for the 16F628 board (the 16F628 uses
RB1 and RB2 for it's USART connection), and are the two top track breaks
shown on the bottom view of the board below.
So,
for use with the 16F876 board fit the top two wire links, and cut the top
two tracks shown, for the 16F628 leave the top two links out, and don't
cut the two top track breaks. This only applies if you are using the
hardware USART, for software serial communications you can use any pins
you like.
Although it's labelled as connecting to
PortC for the 16F876 processor board (and is also designed to connect to
PortB for the 16F628 processor board), as
with most of the boards, it can also be
connected to other ports if required, and if not using the hardware USART.
 |
This
is the top view of the RS232 Board, there are four wire links (the
wire below the chip is the lead of the capacitor), the
three veropins at the bottom right are the connections to the 9 pin
D socket. As it's not too clear, pin one of the chip is at the left
hand side of the board. |
 |
The
bottom of the RS232 Board, it has fifteen track breaks, marked with
blue circles (as usual). |