User manual

MCP2030 Bidirectional Communication Demo Kit User’s Guide

3.3.6 Programming of the Transponder

The Transponder Demo Board has a Programming Connector (J1) for In-Circuit Serial

Programming™ (ICSP™). See Figure 3-3 for the J1 Programming Connector. The

transmitter can therefore be re-programmed using the PICkit

2 (or PICkit

1) without

removing the microcontroller from the board.

FIGURE 3-3: J1 Programming Connector.

3.3.7 Power

The Transponder Demo Board is powered by a standard Lithium 3V coin cell battery.

3.3.8 Microcontroller Firmware Algorithm

When the Transponder Demo Board is powered on, the PIC16F636 (MCU) programs

the configuration registers of the MCP2030 and also the configuration register of the

MCP3421 (ADC). After these set-up procedures, the MCU enters a low-power sleep

mode while the MCP2030 is looking for a valid LF command. The MCU is waken-up by

the demodulated output from the MCP2030 or button switch event. If the MCU receives

a valid demodulated data from the MCP2030, then it transmits its 32 bit transponder ID

followed by the 16 bit received signal strength indicator (RSSI) data. If the MCU is

waken-up by a switch event (SW3 and SW4), it transmits the corresponding switch

event data. The data is always attached to the header (See Figure 3-5). The Transpon-

der ID is set to “04234567” and programmed in the EEPROM. The RSSI data is pro-

portional to the LF signal strength. Therefore, the RSSI data increases as the

Transponder Demo Board comes closer to the Base Station Demo Board. The Tran-

sponder Demo Board transmits each byte LSB first and also transmits a parity bit at

end of each byte. See Figure 3-5 for more details of the Transponder Demo Board data

stream. Figure 3-4 shows the firmware flow chart.

The MCU firmware is included in the MCP2030 Bidirectional Communication Demo Kit

CD ROM.

MCLR

ICSPDAT

no connection

ICSPCLK