3 digit battery voltmeter (0 to 20VDC) for cars and motorbike

Easy and Simple Voltmeter Circuit

In every automobile info cluster, everyone needs to know about their battery status, some cars/motorbikes having that features but i don't think they all are showing in volts. some times we need to know about battery charging voltage for overcharging, over draining etc. it will helps user to troubleshoot their electrical systems as well.

Circuit:

The Above figure is circuit of voltmeter, I have used bus over there (blue color) to simplify the work.

• Note: Before connecting high voltage to the network, Make sure of configuration of input voltage divider network (ADC input pin connection) they are R12,R14,R14. After confirming voltage at the junction of R13 & R14 is < =5.1V, connect to microcontroller input.

Components: (some components in circuit diagram is not same as real parts)

• IC1:PIC16F684
• IC2: 7805 (I recommend Filtered voltage regulator circuit)
• R1,R2,R3: 1K Ohm.
• R5 to R11: 330Ohm or 470Ohm.
• D1:5V zener diode.
• T1,T2,T3: BC547
• DIS1,2,3: Common cathode 7 segment display.

Description:

This voltmeter can show voltage from 0.1V to 20.0V
The battery voltage is fed to the resistor voltage divider network to reduce voltage for 20V range to 5V range. That reduced voltage to the ADC of PIC microcontroller. the controller will convert ADC Hex value and show them in multiplexed 3 digit 7 segment display.

PCB,Project files and .HEX files

PCB

Simulation circuit

Project files:

Yandex Folder

Arduino sketch and circuits are coming soon...

I tried my best to simplify and provide all the information, If you feel problem in any ask me for solutions.

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LED Breathing circuit (PWM) for highpower LED, LED strip etc

LED breathing is one of the eye candy for every vehicles, LED fad in and fade out effect looks awesome with under body lighting.

We are using PIC microcontroller here, PIC12F683 is a small 8 pin circuit and having 1CCP module (PWM) in it, it wont cost too much, may be within Rs.60 (1$).we are using 1 pin for PWM output, 1 pin for button pressed feedback and another for button to vary breathing speed (delay between changing duty cycle of PWM), other 3 pins are left spare, you can use it for any other functions like blinkin.


Don't forget to get clean 5V DC power supply circuit before this

Circuit

*The components used in this circuit diagram of same package of original components,  

 Components

IC1:PIC12F683

R1: 1K Ohm

R2: 4.7K Ohm

R3: 100 Ohm

R4: 10K Ohm

R5: 470 Ohm

T1: BC547

Q1: TIP127

Push button, LED.

PCB, Project files & .HEX files

• Project files : Yandex Folder

Any problems?? Comment below

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Revealing of Digital RPM meter Technique

The digital RPM meter calculates Revolution of piston or flywheel. The technique behind this is CCP (Capture and Compare) and Pulse width.

This is give away of "MMD ramper" secrets ;-)

INPUT:

• All motorbike or Car engine is provided with fry-wheel with pulsar coil to activate spark plugs. these pulses can be taken for RPM reading.
• The spark plug sensor can also be applied, but the problem is unwanted high level spike and distortions, and also not that accurate as previous method

CCP: 

This includes 3 modules in microcontrollers they are, Capture and compare/ PWM/PPM, we need only Capture and compare here.
Capture and compare the name itself says capturing pulse and comparing them, This module takes pulses as input. If one pulse occurs, the timer will starts for either rising edge of pulse or falling edge (whatever programmer specified) and waits for another pulse to occur, after second pulses specified edge it gives the timer outputs in form of bits ( say timer of 16 bits it gives output like 65535-lapsed bits). That means you got period (1/frequency) of pulse.

Conversion:

Got pulse frequency in bits form for calculations

Actual formula

f = clock(32MHZ)/(8(prescaler)*(65536-timer value))

My formula by trial and error:

countrevalue = (60000.0 / (0.008 * rpm_timer (16bit timer value) ) ; // For 32 MHZ

• for RPM (For 4 stroke bike or 2 cylinder car) = countervalue*1.085; 
• for RPM (For 4 cylinder car) = countervalue*0.5425;

RPM output will be in form of 1K RPM = 100 (10RPM), you can divide the value by 100 to get in form of 1s(1=1k)

Pulse:

I have differentiated pulse pattrns for motorbike and car,

• For motorbike
• 4 stroke: you will get 1 pulse per 2 rotation of fly-wheel 
• 2 stroke: 1 pulse per 1 rotation
• But car having 2 to 4 pistons (cylinders), 
• Car with 2 cylinders (cylinders) gives pulses same as 4 stroke motorbike.
• Car with 4 cylinders will give 2 pulses per 1 rotation.

Sensor circuit

The diode gets pulses from pulsar coil, and then that is fed to protection circuit. Because the input voltage may be in 10 to 18V dc, we need pulses in 5VDC for microcontroller TTL level. After transistor the pluse is inverted, so we have added schmitt trigger IC,

output graph

Red -Input say 24V

Orange - voltage at transistor base

Yellow - at transistor collector

Green - Output 5Vdc

Output

You can get output in forms of 7 segment, Alphanumeric LCD or even led graph.

My suggestion:
PIC18F26k22 (40 pin)
2 - 7 segment display (not multiplexed) with 13 LED bargraph.

RPM meter working video

Happy Programming,

Correct me if i'm wrong,

sources:

• http://www.microcontrollerboard.com/pic-timer1-tutorial.html
• http://www.mikroe.com/chapters/view/53/chapter-5-input-capture/
• http://www.mikroe.com/chapters/view/6/chapter-5-ccp-modules/

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Programmed LED strip strobe circuit (Multi type with 2 channels)

Mainly designed for police like light switching. This circuit works best with LED strips, High power LEDes, and also Applicable for Indicators.
Well Programmed, 3 Switchable patterns, 1 pattern includes 3 set of blink types
This circuit is made by PIC microcontroller, here I pre-programmed for 3 sets of 3 type functions, You can edit that program…
The given PCB is designed with SMD packages,The project also including schematic with normal components make PCB yourself.

This circuit is formally “MMD Blinker”, made by / made for “Mozambi Moto Digital”

Schematic:

Components:

• IC1: PIC12F675 (wrong in schematic, same package and pin-out)
• IC2:LM7805 (wrong in schematic, same package and pin-out)
• Resistors: 10K, 1K, 4.7K, 100 Ohm.
• Capacitors: 0.1uF (tantalum recommended) .
• Diodes:
• D2:1N4007
• D1: 5V1 Zener diode.
• Q3,Q4: BC547
• Q1,2: PNP high power any.

PCB layouts, Project files(Eagle & MikroC) and .HEX code

• MikroC file: Download 
• Eagle File: Download 
• Programeed .HEX file: Download
• SMD-PCB
  

If any problems. comment below

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Modified 2 stage blinker circuit for LEDes and brakelight

This circuit is like an advanced version of first blinker circuit, it uses 2 astable circuits, not 2 IC. We can use 556 here. 2 Astable multivariator of Low and High frequencies are cascaded and gives good programmed pulse like 1 long pulse and 2 to 5 sort pulse (Depends upon setting).

The below circuit shows Multi-function blinker circuit

Components:

IC: U1A,U1B : LM556 (Duel timer IC)
Resistors: R1: 1.2K, R2:1K*, R3 750 Ohm, R5:220 Ohm
Pot: R4:1K Ohm, (R2:2K*)
Diode: D1,D2,D3: 1N4007.
Transistor: Q1: MJE200 or any power NPN transistor.
Capacitors: C1:100uF, C2,C4:10nF, C3:22uF.

Description:

• The First stage multivibrator is set to 5 hz, 50% duty cycle (on off 5 times in second ;) ).
• The second stage is a variable one. it varies from 15hz to 160hz
• When first stage in OFF state the second stage is ON -> High only
• When first stage is ON, The trigger circuit will activate second stage and low frequency pulses

Output graph:

PCB Layout & Project files:

• Multisim
• Cadsoft Eagle

If any problems, Comment below

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Simple 12V blinker (strobe) For Horns,Brakelight etc

Its a simple 555 Astable multi-vibrator circuit, for blinking 12V DC.

• It can be connected for brake light, blinking brake-lights draws more attentions than normal ones.
• Can be connected for horns for stroked sound (relay is needed).
• Can be used with LED strips.

Below schematic shows circuit of blinker.

Components:

1. U1: LM555
2. Resistors: R1:100 Ohm, R3:220 Ohm
3. Variable resistor (Potentiometer)R2 2K ohm
4. Capacitors: C1: 22uF(electrolytic),C2: 10nF (Ceramic or tantalum).
5. Transistor Q1 MJE200G or any NPN power Transistor
6. Diodes: D1: 1N4007, D2: 1N4745 (16V zener) -1 
7. Relay*.

* Ground may be body or battery -ve terminal.
*No need of 10K resister at output.

Connection for brake light:

PCB layout & Project files:

 

Project:

• Multisim Project: Downlaod

• Eagle cad PCB project : Download

If You have any problems, Comment below.

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First thing is first

Before any electrical modifications please be aware of these things

Battery

Get your motorbike is up and ready, Check and maintain it for proper voltage.

1. check the battery level when engine off that is 12.3V or above.
2. check the battery voltage when engine running that has to be battery volatge + 1.5 volts,

Example: Your battery level at engine off is 12.3V, then engine on (Charging voltage) will be 13.8 or above.

If your bike is out of battery connection, first heck for fuse. If fuse is blown, then check for short circuits in wiring harness. Please don't bypass fuse, It may spoil your good battery.

Contacts

Keep all electrical contacts proper and good, make sure every cut or joint has insulated. Make use of metal connectors while joining wires to devices like Horns, relays, etc., please avoid skinning wire and twist connections.

Before doing any project with Microcontroller or any sensitive 5V device, Get pure 5V DC circuit first.

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