DETERMINE FREE PROPELLER PINS
ROBOT EXPLORER LOG 5
CURRENT CHIP PINS FREE
PROPELLER 1: 11 PINS FREE
PROPELLER 2: 7 PINS FREE
We're taking this robot to the outer reaches of the Solar System! Follow along as we construct this little explorer craft that will go down to the surface of a new world that's alien to us.
In this update, we've removed the left and right IR navigation and replaced it with Ping ultrasonic navigation. The IR took up 4 pins so now the robot has 4 extra pins on the first propeller chip.
The ambient light level detectors are removed and replaced with the more sensitive TLS230R programmable chip.
On the second Propeller chip, two light to frequency converter chips (TLS230R) are added. Each chip uses 3 pins. Propeller two will have six more pins used.
On the second Propeller, the QTI sensor will be removed due to its limited range in the specs. This will free up 3 pins.
Also removed from the Propeller 2 are two CDS ambient light sensor cells freeing up two more pins.
The reason two light to frequency chips will be used is because one is pointed up to establish a baseline reference for calibration and the second chip will point down at the ground to help estimate the type of ground surface material, based on an average of light reflectivity.
Another reason for selecting the chip: the chip is much more sensitive compared to other sensors and it can be programmed for great sensitivity level or modified. This is a desired feature for exploring the outer planets and moons which have no more lighting than Earth's twilight.
The chip is also programmable to compensate for window dust and degradation, by increasing the light level sensitivity as needed.
Again, we attempted to combine both Propeller boards into one but there was a shortage of two pins.