The CM02 module, together with its companion RF04 module, form a complete interface between your PC and our range of I2C modules. You can send commands down to your robot and receive telemetry data back up to the PC. Now you have all the modules necessary to control your robot from your PC. The CM02 is powered from your robots battery, which can be anything from 6v to 12v. The CM02 can monitor battery voltage and report this back to the PC (so your robot knows when its hungry!). There are four I2C connectors on the CM02, but your not limited to four I2C devices. In practice, you may only need one connector and route the I2C bus around all the modules you wish. Bit rate on the I2C bus is approximately 100KHz.
Uses EasyRadio Modules, no need to write encoding/decoding software.
Power Requirement - 6v - 12v Battery
Over Air Data Rate - 19200 bps.
Default Frequency - CM02-400 433.92MHz, CM02-900 869.85MHz
Range - Up to 250m line of site, Up to 150m for CM02/900
Use with - Any I2C device
License Exempt Frequency Bands
The CM02 is available in two versions. The CM02/400 uses the LPRS EasyRadio ER400TRS module which operates at 433-4MHz. The frequency allocations between 433-4MHz are Pan European and also extend to South Africa, Australia & New Zealand.
The CM02/900 uses the ER900TRS module for EU (868-870MHz) or USA (902-920MHz) markets. Power output up to 10mW. NOTE restrictions in USA to 1mW and 5mW EU.
Be sure to order to check which type may be used in your country, and order matching RF04/CM02 modules, either the RF04/400 and CM02/400 or the RF04/900 and CM02/900.
In 2005, LPRS updated the EasyRadio module, Here are the data sheets for the original ER400TRS and the latest ER400TRS-02.
A 3pin header is used to supply the power for the CM02. A 5v regulator on board supplies the CM02 and other modules. The regulator can supply 1Amp, but in practice this is limited more by the power dissipation, which will be worse, the higher the battery voltage used. Just make sure the heat sink doesn't get too hot! Our test robot, which comprises of CM02, an MD22 motor drive, I2C LCD display, SP03 speech module, CMPS03 compass and eight SRF08's requires 155mA in operation and with a 14v supply the regulator heat sink is just detectably warm. (155mA for the 5v logic - the motors take a lot more, but that doesn't go through the regulator). The slide switch is on the battery side or the regulator. This doesn't switch off the motor power to the MD22. However since the MD22 only takes leakage current when the 5v power is off (we measured 1.5uA) we use it as the robot power switch. If you do that, remember to disconnect the battery before working on your robot. The regulator is a low drop type, so you can use battery voltages of 6v to 12v.