Homebuilt RS232 LCD Interface

There is enough of poorly constructed RS232 alike TTL level interfaces (+5volt), this one generates its own +/- 10..11 volts as RS232 specs require, and is able to use very long cables like RS232 can, and protects computer as well, nice in funny environment like inside a "MP3 in car" setup. There is plenty of ready RS232-Lcd controllers for sale, at least 3 types I know about... Common to them all is that they are slow or do not have button support and/or are expensive... that’s my opinion.

The described circuit focuses on a robust RS232 interface that operates at TTL levels (+5V) while generating the necessary voltage levels of +/- 10 to 11 volts in accordance with RS232 specifications. This design is particularly advantageous for applications requiring long cable runs, as it maintains signal integrity over extended distances, similar to traditional RS232 implementations.

The circuit typically includes a voltage level shifter or a dedicated RS232 driver IC, which converts the TTL signal levels to the required RS232 voltage levels. This driver IC ensures that the output signals meet the RS232 standard, which is crucial for compatibility with various devices and equipment. The use of such a driver also provides electrical isolation, protecting the connected computer or microcontroller from potential voltage spikes or noise that may occur in automotive environments, such as those found in an "MP3 in car" setup.

Additionally, the design may incorporate capacitors for decoupling and filtering, ensuring stable operation and reducing noise. The circuit can also include protection diodes to safeguard against reverse polarity and over-voltage conditions.

Furthermore, the mention of RS232-LCD controllers indicates that this interface can be utilized for controlling LCD displays via RS232 communication. However, it is noted that many commercially available RS232-LCD controllers may have limitations such as slower response times or lack of button support, which could affect user interaction and overall functionality. This highlights the potential advantages of custom-designed solutions that can address these shortcomings while providing a cost-effective alternative.

In summary, the described RS232 interface circuit is designed to meet the specific requirements of robust communication in various environments, emphasizing reliability, compatibility, and protection for connected devices.There is enough of poorly constructed RS232 alike TTL level interfaces (+5volt) , this one generates it`s own +/- 10..11volts as RS232 specs. require , and is able to use very long cables like RS232 can , and protects computer as well , nice in funny environment like inside a "MP3 in car" setup.

There is plenty of ready RS232-Lcd controllers 4 sale , at least 3 types I know about... Common to them all is that they are slow or does not have button support and/or are expensive... that`s my opinion 🔗 External reference