Networking multiple microcontroller boards

There are some applications that require inter-networking multiple microcontrollers or multiple microcontroller boards. For example, different MINI-MAX/51-C2 boards may be operating as independent data collectors/data loggers in different parts of a plant or building automation system. Each board may have its own Real-Time Clock ( through MMC-RTC-1 peripheral board ) and there may be a need to synchronize the clocks on each microcontroller board to the same central clock for accurately synchronizing all the data that is being collected.

Intern-networking of multiple microcontroller boards can be achieved in few different ways:

1) Port I/O to Port I/O: this is one of the simplest methods. Simply connect 4 port pins from one board to the other and use a common Clock signal ( another Port I/O pin ) to notify the receiving side that the data is available. For example, assign this connections on both sides:

Pin Description
P2.0 Data 0
P2.1 Data 1
P2.2 Data 2
P2.3 Data 3
P2.4 Clock

2) I2C: MINI-MAX and PRO-MAX boards all support I2C 2-wire bus protocol. One board can be master and the other boards can be slave.

3) RS232: When only 2 boards are communicating and if the RS232 ports are not being used for any other purpose, this is another simple method. Simply connector the RS232 port of one board to the RS232 port of the other board using the CNM1-9F9F-6 NULL Modem cable.

4) Ethernet: When networking MINI-MAX/51-E boards, ethernet is an option. Ethernet is fast and reliable. If you wish to connect only two MINI-MAX/51-E boards to each other, simply use a cross networking cable. No hub is needed. When networking multiple MINI-MAX/51-E boards or when making them part of an existing 10 Base T network, use a straight-through CAT5 cable to connect the boards to the hub(s).

5) Wireless: MaxStream, Inc. sells some wireless RS232 modules that you can use to interface our microcontroller boards to each other through the wireless with rates up to 38,400 bps and up to 300 feet (90meters) indoor, 1000 feet ( 300 meters ) outdoor/line-of-sight range. We have tested these modules with our microcontroller boards. Please contact us for more information.