Most off board peripherals we use
are connected using the RS232 standard. This standard
has been in existence since the 1960s and is very
easy to implement using embedded systems hardware.
As mentioned previously RS232 serial communications
are used in wireless modems, landline modems,
GPS receivers, data loggers, and serial field
devices both old and new, and worldwide. Wireless
RS232 connections are also available. While these
devices are not going away any time soon, PC and
especially laptop manufacturers do not seem to
understand this. It is common to find laptop models
without a serial port nowadays. Luckily some upper
end models are still equipped with RS232 ports.
You might ask about USB to RS232 converter kits
or PCMCIA cards. It seems sometimes they work
and sometimes they do not. Maybe they have recently
improved, but I’ll take my good old serial
port any day.
We have programmed RS232 communications, completed
MAX 232 style circuits, using both Rabbit Semiconductor
and Microchip PIC controllers. Our software utilities
analyze hex outputs and we see the exact output
from the device. HyperTerminal only displays ASCII
characters and is sometimes useless while troubleshooting.
This is not an RS232 tutorial in any way but
for more information, and diagrams go to the follow