Hello guys, This is my second electronic project .Please share and vote if you like.
What is PEDOMETER?
Answer- A pedometer is a device, usually portable and electronic or electromechanical, that counts each step a person takes by detecting themotion of the person's hands or hips. Because the distance of each person's step varies, an informal calibration, performed by the user, is required if presentation of the distance covered in a unit of length (such as in kilometres or miles) is desired.
Presented here is a simple pedometer circuit. It measures the distance covered by you while walking. It may not work very well for running!
Step 1: Item Required.
- CD4093 quad 2-input NAND schmitt trigger X 1
- CD4024 counter/divider x 1
- CD4026 decade counter/divider x 2
- BC327 pnp transistor x 2
- 22k Resistor x 2
- 2.2 m Resistor x 1
- 4.7 k Resistor x 3
- 47 ohm Resistor x 1
- 1k Resistor x 2
- 47nf ceramic disk capacitor x 1
- 330nf tantalum capacitor x 1
- 10nf ceramic disk capacitor x 1
- LTS543, 7 - segment display x 2
- Tilt/ mercury switch
- on/off switch x 2
- Tactile switch x 2
- 2 pin terminal block
- 3v battery. ( i use 9 v battery with proper resistor, you only use 3v)
- An empty plastic box
Step 2: Construction.
- Take a vero board, and first assemble 4093 IC and then other IC according to systematic.
- if you want to make a printed circuit board. i also upload actual size pcb design and component layout.
- add tilt sensor .
- add resistors
- add capacitor.
- now add 7-segment display.
- do not attach (reset) and ( display) switch on board, because it attached on plastic box. these switch install later.
- solder components, according to given systematic.
- cut the board according to size of box.
- take box and cut two windows for displays
- also make 4 holes for switches (reset) and for (display)
- install the circuit board into the box , carefully.
- add on/off button on the side of plastic box.
- add chart paper and name marking.
i did not add any buzzer, because i don't need it. ( if you want to add , install buzzer with 47 ohm resistor)
The circuit is built around quad 2-input Schmitt trigger CD4093 (IC1), CMOS ripple carry binary counter/divider CD4024 (IC2), decade counter/divider CD4026 (IC3 and IC4), two transistors BC327 (T1, T2) and some other components.
Gates N1 and N2 of IC1 form a monostable multivibrator that receives trigger input from tilt or mercury switch S1. When you lift your foot up and touch the ground back during walking, the mercury inside the switch makes a contact with its two metallic leads. This makes the current to flow between the metallic leads and a pulse is generated at pin 4 of IC1.
This pulse is fed to pin 1 of IC2 that produces a divide-by-64 counter. Its output is given to inputs of gate N4 of IC1 and the output of N4 is fed to the base of transistor T2 through resistor R8. Transistor T2 drives the decimal point segment of common cathode 7-segment display (DIS1)
IC3 and IC4 are configured as decade counters to drive the 7-segment displays DIS1 and DIS2, respectively.
Step 3: Working.
How it works .
Switch S4 resets these two counters and switch S5 enables DIS1 and DIS2 displays.
Transistor T1 drives the piezobuzzer (PZ1), which beeps after every two steps (one stride), provided switch S2 is closed. DIS1 and DIS2 displays indicate the distance covered in metre (m) and kilometre (km) units, respectively.
Generally, walking step of each individual is slightly different. Here, we assume that a single step is 78cm long, which is the average. According to this, 64 strides equal 100m (that is, 2×0.78×64=99.84m or 100m (approx.)) or 128 steps equal 100m.
DIS1 increments the digit after every 100m distance. That is, DIS1 displays 1 when distance covered is 100m and 2 when distance covered is 200m, and so on. After digit 9 in DIS1, DIS2 increments from 0 to 1 digit. The decimal point (dot) of DIS2 always glows to indicate separation of kilometre from the metre unit.To save battery power consumption, DIS1 and DIS2 displays illuminate only when you push S5. If you want to reset the counter circuit, both switches S4 and S5 must be pressed simultaneously.
If you want to continuously illuminate DIS1 and DIS2 displays, remove switch S5 and connect the junction of S4 and emitter of transistor T2 to 3V.
use 3vbattery (not use 9v) ......... take two AA size batteries , connect them in series and use.
Step 4: Done.
Enjoy this built and keep walking.
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