This circuit Can be Used to Measure distance covered by bicycle using a reed switch as the sensor and use the magnet tied to a wheel. Detection of rolling is then made by a proximity effect, Pls the magnet close to the reed switch. This close / open reed switch contact Can use to make on-off signal. 68HC908QY4 microcontroller function for counting the pulse signal Produced by reed switches, and then Direct display in meter unit through lcd 16 x 1 line LCD
Pengukur Jarak Prototipe
Skema rangkaian pengukur jarakTo Interface signals for LCD are D4-D7, RS and E. 4-bit It was interfacing, no busy checking. D0-D3 and R / W # is not Used, so We must tie to GND. Since We Can not check Busy bit, so the delay routine must be ready LCD Used to wait for command and writing data. The sensor inputs are PTA2 for reed switch contact and PTA0 for 0 / +5 V analog input can use a small phone jack for both sensors. in the image below shows a sample sensor and cable making. Later shrinkage tube We need to protect the sensor. The position sensor Pls Pls fix to the bicycle wheel Also Important. We need the magnetic flux perpendicular to the contact.
sensor and cable makingSoftware/program
Software for write to68HC908QY4 microcontroller is s-record.hex ,which was written by C-language ,the source code is firmware source code.
source http://chaokhun.kmitl.ac.th
