Datasheet

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6.6. Audio (Audio Out, Mic, Speaker, Volume Potentiometer)
An amplified stereo audio output jack is provided and connected to the timer circuit. TO01 is used for Right audio
channel and comes out on CPU pin 40. TO02 is used for the Left audio channel and comes out on CPU pin 39. The
stereo amp is powered by a National Semi LM4808. The on-board speaker is powered by a LM4889 audio power
amplifier which can be disabled by setting P42 low. An on-board Analog Devices Inc. (ADI) Silicon microphone
(ADMP401) is connected to the ADC channel AN5 (CPU pin 51) using an ADI SSM2167 low voltage Microphone
preamplifier.
6.7. Serial port
The Serial module allows the MCU to communicate to a Host PC through the RS-232 connector, J14, using UART0 on
the RL78. The serial port is configured in DCE mode allowing direct connection to a PC without a Null modem. The serial
module can also be used as a serial debug port. Table 6-4 contains details of the specific pin functions and their
locations.
Description Function MCU Pin Connector Pin
TxD0 Serial Transmission Pin 44 J14.2
RxD0 Serial Reception Pin 45 J14.3
Table 6-4: Serial port pin details
6.8. 3-Axis Accelerometer
The RDK includes an Analog Devices ADXL345 3–axis accelerometer. The part is accessed by the I2C Bus (IICA0)
with the following address:
I2C Address: 0x3A (0011101r) where r = R/W
6.9. Digital Temp Sensor
The RDK includes an ADT7420 Digital Temperature Sensor. The part is accessed by the I2C Bus (IICA0) with the
following address:
I2C Address: 0x90 (10010aar) where aa = A1:A0, r = R/Wn