The Dalf Motor Control Board was designed as a companion to a pair ofOSMC Motor Drivers to control a pair of brushed PM DC motors, however it is usable with other motor drivers that use signed magnitude PWM controls. It also makes a wonderful development board for other applications because of the abundant IO and the use of standard software tools. The built-in firmware provides several different open and closed loop motor control methods. For closed loop applications it uses standard quadrature feedback from incremental encoders. Optionally, for suitable applications, analog position feedback may replace the optical encoders. Based on the PIC18F6722 running at 40MHz (10 MIPS), the hardware and firmware provide multiple user interfaces including: 3 channel RC with either tank or mixed modes, analog controls (center off or full range) using off board potentiometers, and serial command interfaces using the serial RS232 and I2C Busses. Closed loop PID using a Trapezoidal Generator is provided for both positional, and velocity controls. Adjustable slew rate is one of many features supported using non volatile storage for motor parameters. Voltage windows implemented using comparator circuitry and digitally adjustable pots provide very fast current limiting response when used with off board current sensors. Features are easily extensible using standard Microchip software tools, the supplied files (main.c + dalf.lib), and the 6-pin modular connector which is suitable for direct plug from the Microchip ICD2 Product. A Boot loader supports firmware upgrades over the serial link. Lots of unused I/O with signals accessible from the screw terminals and ribbon connectors. Ample headroom for additional code development in both FLASH and RAM memory. The +5V power supply supports a robust BEC for off board usage. Two I2C busses and two RS232 ports are routed to connectors. Detailed documentation including a voluminous Owner's Manual describing all features, and a somewhat less imposing, Getting Started Manual, are available for download.

Differential Robot Base

12V geared PMDC wheelchair motors paired with US Digital incremental encoders (CPR=64) provide quadrature signals for position and velocity control.

Also shown are two OSMC Motor Drivers with cooling fans. The motors are over-driven with an 18V supply for a maximum RPM of about 360. Not shown is an additional 3.6:1, belt driven, gear reduction assembly that drives the 10" wheels.

The Dalf Motor Controller and OSMC Motor Drivers are available.

Experimenters Breadboard

A couple of motor/encoder combos (CPR=20), a dual motor driver, an R/C receiver, and a small breadboard for LED's, switches, pots, or whatever. The receiver antennae is shown in the background wrapped around a pencil (very professional!).

When driven with +12V the motors have a maximum RPM of about 4,000. The motor/encoder combo units (also gear reduction assemblies) available.

Music Dancing LEDs

If you are a music lover then you can enhance your music experience by making a Music Dancing LEDs project all by yourself if you have a little bit knowledge about electronics.

The circuit comprises of 3 different bands Red,Green and Blue for high,medium and low frequencies respectively. It is a simple circuit which you can assemble on a bread board easily by following the given circuit diagram and buying the respective components for it. I have tested this circuit by myself by assembling it on a vero board so it is 100% working

you can detect earthquake with your phone?

Almost all smartphone users know that all smartphones now a days are coming with a lot of sensors in them. Even the most cheap android smartphone has Accelerometer which is used for Auto-rotate. I was surfing the web news and found a really great tool which can graph the movement of your phone or tablet.

Then I read a post which says that you can use your phone as a basic seismometer. Don’t expect professional level results from your phone. So let’s get to it.

How to use your phone as earthquake detector.

Here is a web-page which is written is simple java-script and works on every modern day smartphone. Just open the link and it will start making a graph of the movement of your phone. Ofcourse you can manipulate the output by shaking your phone. Even if I open the link in my laptop, Which doesn’t have any accelerometer in it, The graph is moving a little.

So, If you thought that you can actually use your phone as a professional seismometer, you are a genius. This is what I am going to show you now. Just open the link given above, and place your phone on a flat surface like a table or ground.

If you see a lot of movement in the graph, either the earth is shaking or your phone’s sensor is faulty. 

I will again mention that you should not use it as a reliable seismometer. But there is something which is better then nothing.

Infrared Security Alarm

Wondering if you can setup a small and cheap alarm system for your home? Then you are at the right place because I present to you an infrared security alarm system that you can create at your home yourself easily by spending some small amount of money and making up a simple circuit if you have good enough knowledge about electronics.

An infrared security alarm system is based on the detection of an intrusion caused by the interruption of an infra-red (which is invisible to human being) light beam being emitted by an infra-red LED and falling on a matched IR sensor. Both the transmitter and the receiver portions separately operate on 6v supplies. The transmitter and the receiver’s circuits can be mounted in an aligned position on the two sides of a door to check intrusion or even on the two facing walls of inside of a locker to give you an alarm whenever an unauthorized person attempts a mischief. The circuit has a provision of both audio as well as visible indications. The audio indicator and the visible indication can be remotely located away from the location of gadget also. The IR based system is very much advanced and works very much accurately. This type of devices are designed and marketed by the different multinational companies.

I have tested this circuit by myself on a vero board and it works 100% accurately.

Components Required:

1. Power Supplies:
   • 2x 220V-9V (or more) Step Down Transformer
   • 2x Bridge Rectifier
   • 2x 7806 IC
   • 2x 3300uF Capacitor
   • 2x 10uF Capacitor
   • 2x Heat Sink
2. Transmitter Section:
   • 1N4148 Diode
   • 1 Kohm resistor
   • 22 ohm resistor (0.5W)
   • 2.2 Kohm resistor
   • 2x 0.01 uF capacitor
   • Pot 4.7 Kohm variable resistor
   • BC547 Transistor
   • 555 IC
   • Infrared LED
3. Receiver Section:
   • TSOP 1738 IR Receiver
   • 2x 220 ohm resistor
   • 1.8 Kohm resistor
   • 2x 4.7 Kohm resistor
   • 2x 1 Kohm resistor
   • 1 Mohm resistor
   • 470 ohm resistor
   • 220 Kohm resistor
   • 4.7 ohm resistor (0.5W)
   • 47 uF capacitor (16V)
   • 2x 0.1 uF capacitor
   • 10 uF capacitor (16V)
   • 100 uF capacitor (16V)
   • 2x BC547 transistor
   • BC558 transistor
   • 3.3V zener diode
   • 1N4007 diode
   • LED green +red
   • Speaker 8ohm (1W)
   • CD4538 IC
   • UM3561 IC

Circuit Diagram:

Power Supply:

Transmitter:

Receiver:

Working:

In the transmitter circuit,we have taken IR because IR is invisible to the eye, where as in case of LASER, which is easily visible to the human eye by which will, alert the unauthorized person. That is why we have taken IR as a transmitter which will transmit a continuous IR signal. The 555 timer generates a 38KHz frequency which is then sensed by the TSOP1738 in receiver circuit.

The transmitted IR signal directly falls on IR sensor TSOP1738. Whenever the IR signal is interrupted, its output pin 3 goes low and IC2 is triggered at pin 5 through transistor T2. As a result, its output at pin 7 goes low (for a preset time) to forward bias siren-driver transistor T2. This condition is indicated by the glowing of LED1. The time-out period can be increased or decreased by changing the value of capacitor C6.

The output tone of siren-sound generator IC3 can be set by connecting its pin 6 to either Vcc or GND. When you connect pin 6 to Vcc IC3 produces the sound of fire-alarm siren, but when you connect it to GND it produces the sound of ambulance siren.

Notes:

• Both circuits have to be powered by different 6v power supplies.
• You may see and check the infrared led is glowing or not by using a camera.
• Receiver circuit may not properly sense the infrared led on a breadboard as it didnt work for me, so its better to assemble the circuit on a vero board or PCB.
• Heat sinks should be used with the 7806 ICs or the IC may get damaged if the circuit is powered on for a long time.
• Alarm turns off after about 5-10 seconds of getting the contact with IR again.
• Range of the circuit is about 5m.
• Vary the variable resistor to increase or decrease the intensity of the IR LED for better performance in lighting conditions.

Enclose your infrared security alarm system in different plastic or metal packaging and install it on adjacent walls of ur door and your home will be in protection.

Light Activated Switch

Make a light activated switch circuit which can be used for switching OFF a particular lamp or group of lamps in response to the varying ambient light levels. The project once built can be used for switching OFF a lamp when dawn breaks and switching it ON when dusk sets in. It can also be used as a night lamp which will turn on automatically at sleeping time when the room is dark.It is the most simple and cheap project for hobby purposes.

This circuit is tested by myself and it is 100% in working condition.

Components Required:

1. 9V Battery
2. LDR (Light Dependent Resistor)
3. Pot 47 Kohm variable resistor
4. 4 Kohm resistor
5. 10 Kohm resistor
6. 1 Kohm resistor
7. 2x 220 ohm resistor
8. LM311 IC
9. BC 107 transistor
10. LED (any color)
11. 1N4007 Diode
12. 12V SPST Relay

Circuit Diagram:

Working:

The circuit is based on National Semiconductors comparator LM311 (IC1) and an LDR. The non inverting input of IC1 is given with a reference voltage of 6V using resistors R3 and R4. The input to the inverting input will be the voltage across the LDR that is light dependent. At darkness the resistance of the LDR will be high and so do the voltage across it. In this condition the voltage at the inverting input will be higher than the reference at non inverting pin and the output of the comparator will be low. When the LDR is illuminated, its resistance drops and so does the voltage across it. Now the voltage at the inverting input will be lower than that at non inverting input and the out put of the comparator goes high. This makes transistor Q1 on and drives the relay. As a result we get a relay switching according to the intensity of the light falling on the LDR.

Notes:

• Adjust POT R1 to set the desired light intensity for switching the relay.For this illuminate the LDR with the desire intensity light.The relay will be either on or off. Adjust POT R1 slowly so that the state of the relay changes.That’s it. Now the circuit is set for the given intensity of light.
• Assemble the circuit on a good quality PCB or common vero board.
• You can use either a 9 V battery or a well regulated & filtered 9V DC mains operated power supply.
• The pin 5&6 (Balance & Balance/Strobe ) of IC LM311 are shorted to minimize the chance of oscillations.
• The pin out of LM311 is also given together with the circuit diagram.

Place your light activated switch circuit inside some small container/box and make sure the LDR is facing outside the box to detect light properly. This circuit is also used in street lights to turn on the lights automatically when it is dark.