Light Seeker Robot Circuit
Created: Sep 29, 2014
No description available.
A Seeker Robot (SeekBOT) is a simple light-seeking robot that reacts when illuminated. Given a scenario the SeekBOT will move towards the light source and compares the light intensity using the two photodiodes. Making a light-searching robot is not a very tough task. You just need patience, perseverance and guts to make the project successful. The SeekBOT presented here can be fabricated within one hour, without using any dedicated microcontrollers.
The circuit uses a MCP6002 dual general-purpose op amp offering rail-to-rail input and output over the 1.8 to 6V operating range. This amplifier has a typical GBWP of 1 MHz with typical quiescent current of 100 microamperes. The MCP6002 is available in 8-lead PDIP, SOIC and MSOP packages.
First part of the circuit is a light-searching sensor (photodiodes) wired around the opamp MCP6002. The opamp is configured in comparator mode, the reference voltage is set at the inverting input pin (-), and then it is compared with the input at non-inverting (+). When the voltage at the non-inverting input pin exceeds this reference voltage, the output of the comparator goes high (H), otherwise it remains in low (L) state. The 2-channel output from MCP6002 is fed to the inputs of the integrated motor driver L293D (U2), which is an easy-to-use 16-pin IC capable of driving two dc motors at a time in clockwise (CW) and counterclockwise (CCW) direction individually. Power supply input of the Seeker BOT is 6VDC.