User Manual

Page 84 of 90
CCT24
Jumper pin sets J12 and J13 normally have shorting plugs installed as shown in Figure 5.8.2, which
connects the CCT24 RADIO_TXD and RADIO_RXD pins to the respective serial data lines on the evalua-
tion board. It is possible to connect directly to RADIO_TXD and RADIO_RXD by moving the jumpers
over. In this case, J11-1 is the input for transmitted data and J11-2 is the output for received data. Note
this a 3 V logic interface. Placing a shorting plug on jumper pin set J6 allows the CCT24 to be powered up
in boot loader mode. This is used for factory code loads and functional testing. The CCT24 has its own
boot loader utility that allows the protocol firmware to be installed with a terminal program that supports
YMODEM. Pin strip J7 provides access to various CCT24 pins as shown on the silkscreen. Pressing
switch SW2 will reset the CCT24.
Pressing switch SW1 switches GPIO0 from logic high to logic low. Pin strip J8 provides access to various
CCT24 pins as shown on the silkscreen. The wiper of pot R10 drives the input of ADC1. Clockwise rota-
tion of the pot wiper increases the voltage. Thermistor RT1 is part of a voltage divider that drives ADC0.
LED D5 illuminates when GPIO1 is set as a logic high output. LED D10 illuminates when GPIO3 is set as
a logic high. The CCT24 interface board includes a 5 V regulator to regulate the input from the 9 V wall-
plug power supply. Note: do not attempt to use the 9 V wall-plug power supply to power the CCT24
directly. The maximum allowed voltage input to the CCT24 is 5.5 V.