Communication module

The Communication module is designed to provide either the wired or wireless communication capabilities. The communication can be established between the controllers, controller and PC or controller and external device.

The main communication protocol used with this board is a serial interface - UART. Controller module can provide two channel UART connection witch can be connected to wired RS232 connectors or wireless ZigBee / Bluetooth module. The selection is done by on-board jumpers. Simultaneously it is possible to use two parallel UART connections but user can choose (with the selection of jumpers) where the controller UART signals are routed. It is even possible to mix one UART Rx and Tx signals between different connectors.

For example if one external device only sends the information (e.g. RFID reader) and another only receives (e.g. serial LCD), it is possible to use more than two UART devices in parallel.

Communication module equipped with XBee module

Module is equipped with two DB-9 connectors witch are routed through the TTL converter MAX232.

NB! This Communication module is not compatible with old Controller module (Atmega128). In case of planning to use this Communication module and old Controller module you need to perform a little modification on the Controller module.

Do not operate with Communication module before disconnecting the MAX232 chip on the Controller module.

(See the guide)

Reason: The Communication module version 5 is designed for the Controller module version 5. Old Controller module has the RS232 interface on the module and it overdrives the Communication module RS232 interface witch results the short circuit.

The module is equipped with the wireless modules, either the ZigBee or Bluetooth ones.

Following wireless models can be found on the board:

• ZigBee module
  • XBee Series 2 datasheet
• Bluetooth
  • Bluetooth datasheet

It is also possible to use the GPS receiver instead of above modules. This module is optional and is provided on the separate request.

The Communication board is connected with the Controller module to the port PE-PB-PD. With jumper it is possible to select which external connector is routed to microcontroller UART ports.

Schematics of port connector and jumpers

DB-9 connectors are for connecting the external devices, another controller or PC in case other party meets the RS232 standard interface. If one want to connect two Controller modules the cross-wired cable (also known as zero-modem cable) must be used.

Schematics of RS232 connectors

Several devices has UART interface instead of RS232. The Communication board has one UART connector under the wireless module.

UART connector pins:

Two 2 mm socket rows are intended for the wireless module connection e.g. Zigbee, Bluetooth or GPS. Only UART signals and 3,3 V power lines are connected as shown on the table below.

Schematics of UART connectors