Hello everyone..

I am getting ready to start my diploma degree project that will be using many 8051 based systems connected to an RS-485 network, an 8051 or 80251 based server with a connection to a PC. Could any one help me out ??

1. I wish to use an RS-485 full duplex network with bus topology in order to connect many 8951 based systems. My number one problem is what driver circuit should i use. I am looking for something with 3 or 4 channels (from the system's side) that also carries a filter. The third channel will be used as an attempt to achieve CSMA/CD. Is there a way i can find an IC that can provide me with the CSMA/CD and also using the serial port on the 8951 ?? I wish to use it for up to 38,400bps transfer speed.

2. Where can i find an RTC that can support an mcu with a clock of 16MHz or 24MHz. The only one that i have found that appears to be really good is an EPSON 6581 that also has a battery holder on it, with 114bytes on NV RAM.

3. Can the SED1330 by EPSON drive an 640x480 monochrome LCD panel ?? Is there a panel and driver/controller set that you can suggest me ??

4. I wish to use the Philips 8554 I2C bus controller with an EEPROM chip. Do i have to use addresses or i can just use it as is ??

5. Is there an IC or a circuit that i can use to interface a 4x4 matrix keyboard ?? It should handle key scanning, debouncing and coding plus interrupting the microcontroller for it to receive the key-code from a on-circuit register.

If you can answer to any of these questions please do so.

There is no need to answer to all of them.

Thank you for the time you spent reading this mail message.

With regards,

Panos Kenterlis
Technological and Educational Institute of Piraeus (BSc student)
Athens - Piraeus
Greece