Small Printed Circuit Board
THIS SECTION IS UNDER CONSTRUCTION

W.Bot

IR Beam

Power station localization

The power station emits an IR beam. The signal is at a frequency of 1,000Hz, with a 20% duty cycle.

The IR beam is used by W.Bot to locate the power station and connect to it. IR beam processing is handled by the devices board.

When the IR beam is detected, the quality of the signal is calculated (RSSI - Received Signal Strength Indicator) executing an A/D conversion on two different stages of the amplifier. This allows to have a wide RSSI range to better identify the distance from the power station, and/or the angle between the power station and W.Bot. This informations are used to correctly locate the power station and connect to it.

IR beam RSSI data structure

Information about the RSSI can be obtained from the devices board sending the read command 0x38.

The IR beam RSSI data structure is:

typedef struct { uint16_t irRSSI1; uint16_t irRSSI2; uint8_t irLock; uint8_t status; } STRUCT_STATIONIRBEAM;

where

  • uint16_t irRSSI1: RSSI at first amplifier stage
  • uint16_t irRSSI2: RSSI at second amplifier stage
  • uint8_t irLock: 1 if IR beam is detected
  • uint8_t status: 1 if IR beam detector is enabled

PIC I/O Pins

Port Pin number Analog channel Direction Description
RA1 3 AN1 In RSSI at first amplifier stage
RA2 4 AN2 In RSSI at second amplifier stage
RA4 6 - In IR beam detector