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 links:

www.camiresearch.com

www.taltech.com