NEX ROBOTICS SPARK V ATMEGA16 Hardware Manual page 25

IR photo diode consumes about 0.5mA when bright light drives the sensor in to saturation. IR
LED if enabled will consume about 30mA current each. Remove the appropriate jumper to
reduce the power consumption of the robot.
Enabling the IR proximity and Directional light intensity sensors
ATMEGA16 microcontroller has only 8 ADCs. 3 ADC pins are shared between IR Proximity
sensors and Ultrasonic Range sensors. At any given sensor location either IR Proximity sensor or
Ultrasonic range sensor can be used. Both sensors can not remain active at the same time. Figure
3.16 shows J2, J3 and J4 settings for enabling IR proximity sensors. Jumpers are marked with
red border. To use IR proximity sensors place the 2 jumper caps of the jumper corresponding to
particular sensor towards "IRP" (IR Proximity sensors). Out of these two jumpers one jumper
connects power to the sensor and other connects microcontroller's ADC pin to the sensor output.
Figure 3.17: IR proximity sensors and correct jumper setting to enable them
Figure 3.17 shows schematic of the IR proximity sensor and the correct jumper setting to enable
them. For jumper positions and pin number of the jumpers refer to figure 3.16.
Figure 3.18: Jumper setting to use IR proximity sensor as directional light intensity sensor
Figure 3.18 shows the jumper settings to use IR proximity sensor as directional light intensity
sensor. For jumper positions and pin number of the jumpers refer to figure 3.16.
IR Proximity Sensor
Left
Center
Right
Table 3.5 IR Proximity Sensor connections with ADC of the ATMEGA16 (after correct
© NEX Robotics Pvt. Ltd. and ERTS Lab IIT Bombay, INDIA
SPARK V ATMEGA16 Hardware Manual
ADC channel number
ADC channel no. 0
ADC channel no. 1
ADC channel no. 2
jumper settings)
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