Dec 142017
 

A fun project kit for learning hobby electronics. This kit (amazon link) is suitable for almost any age hobbyist but if younger than 12 it would be wise if someone older and with a little more experienced helped.

Put together and ready to test.

Really enjoyed putting this little line following robot car kit together. Instructions in English are available here in PDF: WHDTS Smart Intelligent Robot Tracking Car Assembly Manual

LM353 Dual Operational Amplifier

The magic for this little robot is performed by an LM353 IC. It’s a sweet little Dual Op-Amp processor.
DUAL OPERATIONAL  AMPLIFIER 8 DIP. The LF353 is a JFET input operational amplifier with an internally
compensated input offset voltage. The JFET input device provides with bandwidth, low input bias currents and offset currents.

Kit Parts

One little detail is the assembly manual shows the LM353 installed incorrectly. Here’s a picture of the right orientation.

The parts come loose in a plastic bag so step one can be identifying what are the parts are and where they go on the Printed Circuit Board (PCB) chassis. If you’re helping a youngster put this kit together you can instruct them in reading the resistor codes or using a multimeter to identify the ratings of the resistors so placement on the PCB is correct. The PCB is really well marked so placement of the components is readily obvious as to the correct location even without referring to the instructions. The one-and-only critique I have is in the English instructions the picture of the LM353 in the socket is wrong. The right way is pin one (marked with a small circle) facing to the front. I’ve attached a picture above of the LM353 IC correctly placed. You can have a lot of fun and learning putting this kit together and understanding the theory behind the way the LDRs (Light Dependent Resistors) detect the difference between the black of the line and the white of the area outside the line. And the way this information is used to keep the Robot Car on the right path.

Well marked component locations.

 

Apr 222017
 

This eBook on Arduino Robotics is really worth your time to look over as it deals with all sorts of fun projects like a wall following robot, segway type robots (list below) and just so much more. If you like it I hope you track down a real copy that you can hold in your hands.


Paperback is just $13.95

Click here to sample this book.

 

 

Linus the Line-Bot
Wally the Wall-Bot
Making PCBs
The Bug-Bot
Explorer-Bot
RoboBoat
Lawn-Bot 400
The Seg-Bot
The Battle-Bot
Alternate Control

Check out all our Arduino eBooks

Mar 092017
 

Phase One of the Volthaus Labs 433MHz remote weather station project is completed. The data currently being sent to the RX (receiver) is Temperature and Humidity. The 1602 LCD display is showing the temperature data in both Fahrenheit and Celsius. While you’re reading this I have moved on to Phase Two which includes adding the BMP180 to the TX (transmitter) and displaying the data inside the lab on the receiver’s 1602 LCD display.

The receiver’s display rotates three screens in a loop.

– Screen One –

– Screen Two –

– Screen Three –

The first screen displays the project name. The second screen show the temperature in Celsius with the humidity and the third screen show the temperature in Fahrenheit and the humidity again. I have it working but there are bugs somewhere preventing the correct data being displayed. All that will be covered in the Phase two tutorial. Building this system has been a learning experience. The goal is to have a solar powered remote sensor array that transmits data including temperature, humidity, wind speed and direction, barometric pressure, altitude, and rain indicator. Instead of using an Arduino I am using an ATMEL ATMEGA328P-PU on both my transmitter and my receiver. Using the Rocket Scream Low Power Library is part of the plan. The loop gathers data from the sensors, transmits them using the radio, then goes back to sleep.  But the unused pins on the Atmega 328 need to be sent to ground using a resistor. I did not do that on the current TX so the Solar panel is not keeping the 18650 charged for more than a few days. In other words it’s working well but I am having power issues. So I will share my progress to this point with you.

The only receiver changes planned for the future will be code updates.

 

 

 

 

 

 

 

In developing this project I have found these online articles to be very helpful.

Mini weather station by indigod0g

 

SOLAR POWERED ARDUINO WEATHER STATION by deba168

 


The best one of all is by a young man named Vlad who lives in Canada. It would be much simpler to just use his system but I really want to develop my own and learn as much as possible in the process. Here is a link to Vlad’s well documented system.

http://denialmedia.ca/weather-station/


First test of the 433MHz solar powered transmitter layout. Using Arduino Uno.

The start of the Atmega 328 based receiver. The 10K potentiometer has not been added yet. Once it is it will allow for contrast control of the LCD 1602 display.

 

 

 

 

 

 

 

 

Facing to the south the panel receives plenty of sunlight

This case is temporary. Mounted in the shady dry location.

433MHz receiver uncovered.

 If you are interested in building a version of this project for yourself you will need:

  • Two Arduino Unos (buy) or Two ATMEL ATMEGA328P-PU (buy) barebones setups.
  • 433MHz RF Transmitter-Receiver pair (buy)
  • One DHT11 (buy) or DHT22 (buy) temp/humidity sensor
  • One 0.9V-5V to 5V dc Boost Step-up Power Supply Module (buy)
  • Li-Ion battery charging module (buy)
  • 1602 LCD display (buy)
  • Solar Panel – 1.6w 5.5v 266ma  (Amazon)

The Arduino code for the project’s transmitter and receiver can be downloaded HERE

 

Weather Station Assembly:

 

 

Transmitter Side:

Connecting DHT11
When using the DHT11 module there is no need to add a resistor between the Data and Voltage pins on the DHT11 as called for when using the bare sensor.

Connect:
– The VCC pin on Arduino’s 5V output or if you are using the barebones Atmega328 just connect to your 5VDC source.

– The Negative/Ground pin to Arduino’s GND or your projects ground point.

– The DATA pin to Arduino/Atmega328 digital pin 4

Connecting RF433 transmitter

Connect:

– VCC pin on Arduino’s 5V output or if you are using the barebones Atmega328 just connect to your 5VDC source.

– The GND pin to Arduino’s GND  or your projects ground point.

– The DATA pin to Arduino/Atmega328 digital pin 12

Receiver Side:

Connecting RF433 receiver

Connect:

– VCC pin on Arduino’s 5V output or if you are using the barebones Atmega328 just connect to your 5VDC source.

– The GND pin to Arduino’s GND  or your projects ground point.

– The DATA pin to Arduino’s digital pin 11 – If you have two data pins you only need to connect one of them.

Connecting the LCD display

To properly connect the LCD display, you will need to connect the following:

– LCD VCC pin to 5V pin

– LCD GND pin to GND pin

– LCD RS pin to digital pin 7

– LCD Enable pin to digital pin 6

– LCD D4 pin to digital pin 5

– LCD D5 pin to digital pin 4

– LCD D6 pin to digital pin 3

– LCD D7 pin to digital pin 2

– LCD backlight: Pin A to 5VDC and pin K to GND/Ground

Connecting the potentiometer

Connect:

– one of the outer pins to Arduino’s 5V output

– the opposite outer pin to Arduino’s GND and

– the middle pin to LCD’s VO

The potentiometer is used to control the LCD’s contrast

This completes phase one of the Volthaus Electronics Laboratory 433MHz Weather Station. Questions, comments, etc. are welcome. 

Oct 122016
 

Hey Volthaus Lab,

A friend of the lab who bicycles to work has asked if something could be designed for help with clearing the road of various animals. A device triggered by a small button on the handlebars. He also pulls a small trailer to which the device and a battery could be placed for power. Lights and siren with 433MHz com from switch to unit.

Imagine an incident like this happening on pavement in the dark.

UPDATE Nov 9, 2016:

The components are coming together. I reflow soldered six three-watt white LEDs to heatsinks and wired them up in parallel to 18650 3.7 volt Li-Ion battery and am getting fair amount of brilliance. And also bought two full fledged sirens from AllElectronics  I did make a couple of Arduino based sirens with a small speaker and they were not what I had in mind. With the new sirens this is shaping up to be quite a road clearing device.

The six 3 watt LEDs

The six 3 watt LEDs

Powered up LEDs.

Powered up LEDs.

 

 

 

 

 

 

 

 

EXTRA-LOUD MINI PIEZO SIREN (left) 2-TONE 12VDC SIREN, WAVE 2 (right)

EXTRA-LOUD MINI PIEZO SIREN (left)
2-TONE 12VDC SIREN, WAVE 2 (right)

The on/off transmitter button will be housed in a small container that I’m planning to have mounted using velcro possibly. For communication 433MHz RX-TX modules will more than transmit the signal the few feet from the handlebars to the actual device.

2-TONE 12VDC SIREN, WAVE 2

EXTRA-LOUD MINI PIEZO SIREN

 

 

 
 

 

 

Sep 102016
 

Do you ever use a transistor in an electronic project then pull all the components back off the breadboard and put them back in stock. And then when you’re ready to use them again you’re just not really sure it’s still in working condition. It’s a frustrating learning situation when building an electronic project and for one reason or another it just doesn’t work, and you’re not confident all your components are working as they should.

Well here’s a project you might find handy to have on your workbench. It’s a simple transistor tester and if you have a dead 9VDC battery lying around then that would be the perfect power source for this project.

Components:

  • LED
  • 10K ohm Resistor
  • 680 ohm Resistor
  • 180 ohm resistor
  • SPST tactile momentary button/switch
  • Breadboard
  • 3VDC – 9VDC power source
  • Transistor to test

Schematic:

schematic00010002

Here is how you connect the components

 

 

 

 

 

 

Tester laid out on the breadboard.

Tester laid out on the breadboard.

 

 

 

 

 

 

 

 

 

Tester in action. Showing the NPN 2N2222 transistor is fully functional.

Tester in action. Showing the NPN 2N2222 transistor is fully functional.

 

 

 

 

 

 

 

 

 

Assorted button you can use.

Assorted buttons you can use.

Basic momentary tactile button is perfect for this project

Basic momentary tactile button is perfect for this project

Bottom view of NPN 2N2222 pins

Bottom view of NPN 2N2222 pins

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This project requires  less than $1 worth of components and can save you from much frustration. I hope you find it helpful. Now I need to make one that will test PNP transistors. So much to learn.

Happy electronic project building!

 

 

Sep 082016
 

If you’re looking for a robotics project to build. And if you want to be fun, quick, and easy this is the robot project for you. I found it at https://www.hackster.io/lovelyideas-in/arduino-remote-car-using-bluetooth-hc-05-android-app-control-3da97d  Mr. Jones Kys did a wonderful job developing this. Everything you need is available for download, including the Arduino sketch, schematic, and Android app.

Bill Of Materials:

  • Arduino – Uno,Nano, or Pro-Mini will work. Possibly others as well.
  • HC-05 Bluetooth module
  • Two DC motors and a chassis (you can be creative with the chassis)
  • L293D Dual H-Bridge motor driver
  • Power source (I used two 18650 Lithium Ion Rechargeable Batteries)
  • The Arduino IDE software (available for free at https://www.arduino.cc/en/Main/Software)
The rough prototype.

The rough prototype.

I put this together using an Arduino Pro-Mini and HC-05 Bluetooth module. An Arduino Nano would also work perfectly. I powered this using two Lithium Ion rechargeable batteries. I ran the hot lead to the RAW pin on the Arduino Pro-Mini. And the 5 volts for the Bluetooth module came from the VCC pin on the Arduino Pro-Mini. I am looking forward to cleaning it up as well as possibly including encoders on each wheel to solve the issue of one motor turning faster than the other, which causes the bot to veer off a straight line.

 

Motor with encoder wheel and two encoders.

Motor with encoder wheel and two encoders.

dsc00030

 

 

 

 

 

 

 

 

You can see in the picture what an encoder looks like and also pictured is the encoder wheel you mount to your axle that spins inside the two protrusions on the encoder. Also you might notice the 0.1uF capacitor I soldered between the two terminals on the motor. That cuts down on theEMF emissions from the motor that can interfere with the radio signal.

Here’s a short video of the robot/car in action.

 

You can download everything you need and check out the project at:

https://www.hackster.io/lovelyideas-in/arduino-remote-car-using-bluetooth-hc-05-android-app-control-3da97d

Jul 172016
 

 

Working with Level Shifterspresents400

Level shifters are a wonderful and very affordable solution when you have a situation where you have to interface a 3.3VDC and a 5VDC device. They are also called voltage shifters and they come in uni-direction versions where the signal only goes one way, bi-directional where signal goes both ways, direction controlled level shifters with a dedicated directional pin, logic level shifters that put logic functionality and voltage translation into a single design, and finally application specific level shifters .You will also find them in a variety of multi-channel types as well as bit rates. In this article we’ll cover the 5VDC/3.3VDC bi-directional 2 and 4 channel types available on Ebay for a very low cost and how to use them in your ingenious projects.

Step 1: Two channel level shifter
2 Channel Version

 

This was my first level shifter. I bought it from a seller on Ebay. When i bought I had not yet worked with level shifting so I did not notice the module was not marked to indicate which side was LV (low voltage) or HV (high voltage). Simply put you supply 5VDC and GND (ground) to one side of the module and 3.3VDC and GND to the other side. The first time i used it I was using a 3.3VDC ESP8266 to wirelessly control a 5 VDC servo. Without the shifter the ESP8266 would not boot up. Once I had the shifter in place it performed perfectly.

The markings that are on the module are:prefaced with an “A” on one side and “B” on the other.

  • AVCC (I soon figured out this was the 5VDC input)
  • ASCL – This seems to indicate the module is I2C compatible.
  • ASDA – In an I2C situation this would seem to be the SDA data signal connection
  • AGND – This pin goes to the ground bus

In this example I’m interfacing a 3.3VDC HC-06 bluetooth module with a 5VDC Arduino Pro Mini to turn on and off an LED using Putty on a BT equipped laptop.

Step 2: 3.3VDC HC-06 Bluetooth – 5VDC Arduino Pro Mini

LED Control Circuit

I also bought some 4 channel shifters and they are marked HV and LV which tells me which side should be connected to the 5VDC power and which gets the 3.3VDC power. They are also marked TX and RX but I disregarded that in this setup and I am having no problems TXing on the RXing channel. I’ve breadboarded a 3.3VDC HC-06 Bluetooth with a 5VDC Arduino Pro Mini. using I’m using PuTTY ( a free SSH and telnet client for Windows) on a bluetooth eqipped laptop to control the Arduino to turn on and off the LED. You can get a free copy of PuTTY at http://www.putty.org/

The Arduino Bluetooth LED control sketch is avalable @ http://volthauslab.com/sketchs/Bluetooth/bluetoothLEDcontrol.ino

Nov 082015
 

In our travels about the Internets we have came across many a helpful website. It is with much joy and satisfaction we share them with you now.


 

Electro Schematics Electro Schematics is a treasure trove of projects (1089 electronics projects and circuits) we are sure will lead you further down the hobby electronic rabbit hole.

 

 


 

allaboutcircuitsAll About Circuits One of the largest online electrical engineering communities. A positive, open community of electronics geeks that enjoy sharing knowledge and ideas.

 


Talking ElectronicsTalking Electronics – The legendary Aussie Colin Mitchell‘s website. This was what started it all for a generation of electronic hobbyists and future electronic engineers.

 


Duino RoboticsA good get started in robotics site. Lot’s of info including Arduino code for DIY obstacle avoidance robots. Links!

 

 

 

 

 


Instructables Instructables is a community driven website that has tutorials (ibles) and how-tos on anything you can imagine. Electronics is only a part of what is covered.

 

 


Electronics For UThe title kind of says it all. If it’s electronics, it’s here. I tend to agree. Based in India this website covers almost every aspect of electronics. It’s worth it to (free) register with them for total access.

 


letsmakerobotsLet’s Make Robots is a total robotic community. Registration with allows you to actively share projects, news, videos and more.

 

 


 Embedded LabEmbedded Lab: An online teaching laboratory for Microcontrollers and Embedded Systems. A very good website heavy on microcontroller use in many projects.

 

 


Electronics Hub

Electronics Hub has a large selection of projects, circuits, and information that will prove quite helpful to hobbyists.


TronixArduinos are the main focus at tronixstuff. In fact they have over 50 Arduino tutorials.


BONUS:

EEV blog

David L. Jones is an electronics design engineer based in Sydney Australia. He hosts the EEVblog, the world’s largest and most popular engineering video blog and Youtube channel. In each episode he shares some of his 20+ years experience in the electronics design industry in his unique non-scripted naturally enthusiastic and passionate style.

 

Sep 272015
 

DC Electric MotorDC Electric DIY Motor Project


Let’s build an electric motor. “An electric motor is an electrical machine that converts electrical energy into mechanical energy.”  We won’t go into exactly how the electricity makes this motor work because that would be a book all on its own, so let’s build this motor and have fun! To learn more about the technical knowledge of electric motors I suggest you start by reading the Wikipedia page.

Bill of Materials (BOM):

2 – Paper Clips
1 – Battery or power supply:  D cell, 9 volt, AA, 2 AA, benchtop power supply
1 – Bread Board, card board, piece of wood to mount the motor or rubber bands to hold paper clips to end of D cell battery
1 – Magnet – Can be a bar, circular, or just about any shape. I used 2 – 13mm diameter Neodymium magnets, and 1 5mm diameter magnet stacked one on top of the other. I drilled a hole in the board to prevent the magnets from snapping to the paperclip axles. These rare earth magnets are extremely powerful. Our motor with these magnets turns at 180 RPM and seems to have much more power than you would get using plain ceramic magnets.
1 – Magnet Wire 22 AWG. It is a lacquer coated copper wire. You can try using insulated wire but your results will probably not be as good as you would get using the proper wire.

Project parts

 

 

 

 

 

 

Building Instructions:

1. Wind the 20 AWG magnet wire into a 20mm circle, making about 12-15 loops. It helps to wrap the wire around a cylinder of some sort to get better results. The coil you have just made is called a rotor.  You want to have a lead coming from each side of the coil about 20mm in length.
Rotor coil

 

 

 

 

2. Holding the coil upright put one of the leads on a flat surface.  Using a razor knife or a small piece of 220 sandpaper, remove the lacquer coating from only the very top surface of the wire.  Leave the coating intact on the sides and bottom. Remove the lacquer from the wire from the very end to right up to where the lead meets the rotor.
3. Remove the lacquer from the other lead completely, 360 degrees around. Again from the tip of the lead all the way to where it meets the rotor.
Base with axel supports

 

 

 

 

 

 

4. Straighten your paperclips and make an axle rest at one end. Needle nosed pliers are very handy for this part of the build. You should make them about 25mm long. Place your axles 60mm apart.

Axel support

 

 

 

 

5. Place your magnet in the center between your axles. Hot glue is good to prevent the magnets from snapping to your metal axles. I drilled a deep hole that could hold all three of my magnets. Using the rare earth magnets which have a very powerful attraction, drilling a hole in your base is a good way to prevent your magnets from snapping over onto your paperclip rotor supports.
6. You can also drill a very small hole in the base to place your axles into for a strong motor. You can also thumbtack them down, or use any other method you can think of, you just want them solid enough to stand upright.

 

Base

 

 

 

 

7. Now set the rotor onto the paperclip axles.  You want your rotor directly over the magnets and close to them as well.  You can place cotton from a cotton ball into the hole to raise the magnets, or any thing that will shim them to just below the path of the rotor as it spins.

Setup

8. Connect your power to your rotor supports by whatever means you have available. If you’re using a benchtop power supply you can connect your alligator clips to the axles. That is a great way to adjust the height of your axles also, letting the alligator clips hold the paperclips at the right height. If you’re using a D cell battery you can stand an axle at each end of the battery and wrap the rubber band around the entire setup. I don’t suggest doing it that way but it does work.
9. Turn on your power supply at 3.3 volts to begin with and increase if needed. Or connect your battery. The neodymium magnet motor sometimes started spinning on its own as soon as the power was turned on. This happened when sending 5v to the motor. You probably will have to bump the rotor slightly to get it started. You should see which direction it has a tendency to spin and that is the direction you want to push the rotor to start it spinning.

 

In this video the motor is powered by two AA rechargeable batteries that supply 1.2v and 2700mA each. Watch it go!

Desktop computer power supply modified to work as work bench power supply.

Desktop computer power supply modified to work as work bench power supply.

 

10. If all is well you should have it running now. Usually some fine tuning is needed to get things working perfectly. Cutting a small disc from a business card and placing on the rotor leads can prevent the rotor from moving laterally and falling off the axle supports.

If your motor still does not run, double check your work! Make sure the lacquer coating was removed exactly as instructed.
When you’re finished turn off the power and put away your tools, any scraps of wire that may have fallen on the floor, etc. A clean and orderly workshop is a safe workshop. Also you don’t want to leave a mess for someone else to clean up. The electronic hobby is a great way to learn, have fun, and make wonderful things that will improve your quality of life. It also is a great way to share your time with your children. This is a fantastic hobby so treat it with respect and be safe. We hope you have enjoyed creating this motor, and reading this tutorial as much as we have had making it. Putting this together for you and spreading the  knowledge of the hobby of electronics has been a privilege.
Thank you.
Volthaus Electronics Laboratory
Sept. 27, 2015

 

 

 

 

 

 

 

 

Aug 312015
 

This night light does not begin glowing until the ambient light in the room is very dim. Others begin glowing when the light in the room is still fairly bright. If your night light comes on when the light in the room is still bright you’re going to be wasting a lot of the electricity in your battery. Another feature is the use of the 9 volt battery using the built-in 5 volt regulated power supply.

power_supply

The completed circuit on bread board with LM7805 based 9v to 5v voltage regulator

 

 

 

 

 

 

 

 

Step 1: What You Will Need

partsComponents:

  • SPST on/off switch (optional)
  • LM7805 Voltage Regulator
  • 0.33uF ceramic capacitor
  • 0.1uF ceramic capacitor
  • 820R ohm axial-lead resistor
  • 100k axial-lead resistor
  • LED – Bright red is easier on sleepy eyes but white will probably be brighter
  • TRANSISTOR 2N3904 NPN
  • GL5528 LDR: also known as a Photocell – Photo Resistor – Light Dependent Resistor
    Bright Resistance (10Lux) (KΩ): 10-20Dark Resistance (MΩ): 1
  • 9 volt battery snap
  • 9 volt battery
  • Breadboard for testing
    a 2N2222 NPN transistor will
    work in this circuit just as well as the 2N3904. The main difference
    between the two transistors is the amount of amperage they can handle.
    If you’d like to see a page comparing the two in depth visit:2N3904 vs 2N2222

Step 2: The Circuit Schematic

schematicThis is the complete circuit. I used CadSoft’s Eagle schematic design software and the LDR symbol is a little different from the LDR symbols I’ve seen on other schematics. Since my voltage to LED1 is 5 volts and that particular LED is rated at 2.0 – 2.4 volts and 18 to 20 mA you could place a resistor (R1) as low as 150 ohms, if I use 2.2 volts as my estimated voltage drop in the equation. It’s the R2 100k resistor that controls how much ambient light will set off the night light. If you replace it with a lower value resistor (for example a 47K resistor) the LED will glow even though the room light is still plenty bright enough for you see around the room.

Step 3: The Voltage Regulator
power_supply2

I built the voltage regulator first and then tested it to make sure it was actually putting out 5 volts. As the 9 volt drains it will maintain the correct voltage this night light needs to operate correctly. I really think it should be able to go for quite some time before the battery will need to be replaced.

Step 4: The Completed Circuit
circuit

Here’s a close-up of the completed circuit. You can see it’s really very simple. In the picture where the LED is lit I have placed a Sharpy pen cap over the LDR to put it in complete darkness. I plan to make some birthday and Christmas gifts using this circuit. Maybe find a Statue of Liberty model where the LED can be placed in the torch Lady Liberty is hoisting up in the air. Another couple of ideas I’ve had are to place the night light in a tiny house so the glow comes through the windows, or a little campsite with the LED in the campfire.

 
circuit_lit