Portable Arduino Lab

Hello everyone....

All are familiar with Arduino. Basically it is an open source electronic prototyping platform. It is a single board micro-controller computer. It is available in different forms Nano, Uno, etc... All are used to make electronic projects. The attraction of Arduino is that it is simple, user friendly, open source and cheap. It is designed for every one which are not familiar with electronics. So it is widely used by students and hobbyists to fulfill their projects more attractive.

I am an electronic student, so I am familiar with Arduino. Here I modified the Arduino Uno for Arduino users which are not come from electronic background (or for every one). So here I converted the Arduino Uno board to a "Portable Arduino Lab". It helps everyone who need it portable. The problems associate with the Arduino board is that it need an external power-supply and it is a bare PCB, so the rough use damage the PCB. So here I add an internal power-supply with multi-function and provide a protective covering to the whole circuit. So by this method I created a "Portable Arduino Lab" for every one. So I created an electronic lab which is fit in your pocket. If you are not in your home or in lab, but you need to test a new idea into circuit, then this make that practical. If you like it, please read the making steps...

My plan is to add a power-supply unit and a cover for the whole. So first we plan about the power-supply.

Power-supply

For powering the Arduino we add a Li-ion cell. But its voltage its only 3.7V. But we need a 5V supply, so we add a boost converter which make 5V from 3.7V. For the charging the Li-ion cell add an intelligent charger circuit which maintain the Li-ion cell in a good condition. For indicating the battery low voltage condition add an extra circuit to indicate that it need a charging. This is the planning for power-supply section.

Here we only use SMD components for this project. Because we need a small size PCB. Also this SMD work improve your skills. Next is the protective covering.

Protective Covering

For protective covering I plan to use plastic name boards. The planed shape is rectangle and make holes for I/O ports and the USB port. Then plan to add some plastic color stickers as art work to improve the beauty.

Arduino Uno

Black plastic name board

Plastic stickers (in different colors)

Li-ion cell

Copper Clad

Electronic components - IC, Resistors, Capacitors, Diodes, Inductors, L.E.D (All the values are given in the circuit diagram)

Fevi-quick (instant glue)

Solder

Flux

Screws

Double sided tape etc....

The electronic components like resistors, capacitors etc.. are taken from old circuits boards. It reduce the project and it give a better Healthy Earth by reducing the waste. The video about SMD desoldering is given above. Please watch it.

The tools which I am used in this project is given in the above images. You choose tools which are suitable for you. The list of tools which I am used is given below.

Soldering Station

Drilling machine with drill bit

Pliers

Screw driver

Wire stripper

Scissors

Ruler

File

Hacksaw

Tweezers

Paper punching machine etc....

Important :- Use tools with care. Avoid accidents from tools.

The circuit diagram is given above. I draw the circuit diagram in EasyEDA software. Then the circuit is converted to PCB layout using the same software and the layout is given above. Also given the Gerber file and PDF circuit layout given below as downloadable files.

Circuit Details

The first part is the battery protection circuit contain an IC DW01 and one mosfet IC 8205SS. It is used for short circuit protection, over-voltage charging protection and deep discharge protection. These all features provided by the IC and the IC controls the mosfet to ON/OFF the battery. The mosfets also have a reverse biased diodes internally for charging the battery with out a problem. If you interested know more about it please visit my BLOG, link is given below,

https://0creativeengineering0.blogspot.com/2019/05/intelligent-li-ion-cell-management.html

Second part is the cell charging circuit. The Li-ion cell need special caring for its charging. So this charging IC TP4056 controls its charging process in a safe manner. Its charging current is fixed at 120mA and it stops the charging process when the cell reaches 4.2V. Also it have 2 status LED to indicate the charging and full charging condition. If you interested know more about it please visit my BLOG, link is given below,

https://0creativeengineering0.blogspot.com/2019/05/diy-li-ion-cell-charger-using-tp4056.html

The third part is the low battery indication circuit. It is designed by wiring the LM358 op-amp as a comparactor. It indicate by turn on the led when the cell need charging.

The last part is the 5V boost converter. It is boost the 3.7V cell voltage to 5V for Arduino. It is designed by using MT3608 IC. It is a 2A boost converter. It is boost the low voltage by using the external components like inductor, diode and capacitor. If you interested know more about boost converter and the circuit please visit my BLOG, link is given below,

https://0creativeengineering0.blogspot.com/2019/05/diy-tiny-5v-2a-boost-converter-simple.html

Procedures

• Print the PCB layout in a glossy paper (photo paper) using photostat machine or laser printer

• Cut it into single layouts using scissors

• Choose a good one for further processing

It s a method to transfer the printed PCB layout to the copper clad for the etching process in PCB making. The layout in the photo paper is transferred to the copper clad by using heat treatment with the help of an iron box. Then the paper is removed by using water, otherwise we don't get a perfect layout without any damage. The point wise procedure is given below.

• Take a required size copper clad

• Smooth its edges by using sand paper

• Clean the copper side by using sandpaper

• Apply the printed layout to the copper clad as shown in the image and stick it in place by using cello-tape

• Cover it by using another paper like news paper

• Heat it (to the side where the printed paper placed) by using an iron box for about 10-15 min.

• Wait some time for cool it

• Then place it in water

• After one minute remove the paper by using your fingers carefully

• Check for any defects, if any please repeat this process

• Your tone transfer process (masking) is done

It is a chemical process for removing unwanted copper from the copper clad based on the PCB layout. For this chemical process we need ferric chloride solution (etching solution). The solution dissolve the non masked copper to the solution. So by this process we get a PCB as in the PCB layout. The procedure for this process is given below.

• Take the masked PCB which is done in the previous step

• Take ferric chloride powder in a plastic box and dissolve it in the water (the amount of powder determine the concentration, higher concentration fastening the process but sometime it damage the PCB recommended is a medium concentration)

• Immerse the masked PCB in the solution

• Wait for some hours (regularly check the etching completed or not)(sun light also fastening the process)

• After completing a successful etching remove the mask by using sand paper

• Smooth the edges ones again

• Clean the PCB

• We done the PCB making

Drilling is the process of making small holes in the PCB. I done it by using small hand driller. The hole is making for through hole components but I use only SMD components here. So the holes are for connecting the wires to the PCB and the mounding holes. The procedure is given below.

• Take the PCB and mark where the holes are needed to made

• Use a small bit (<5mm) for drilling

• Drill all the holes carefully without making any damage to the PCB

• Clean the PCB

• We done the drilling process

SMD soldering is little bit harder than the ordinary through hole soldering. The main tools for this job is a tweezers and a hot air gun or micro-soldering iron. Set the hot air gun at 350C temp. Over heating some time damage the components. So only apply limited amount of heat to the PCB. The procedure is given below.

• Clean the PCB by using PCB cleaner (iso-propyl alcohol)

• Apply solder paste to all the pads in the PCB

• Place all the components to its pad using tweezers based on the circuit diagram

• Double check all the components position are correct or not

• Apply hot air gun at low air speed (high speed cause misalignment of the components)

• Ensure that all the connections are good

• Clean the PCB by using IPA (PCB cleaner) solution

• We done the soldering process successfully

The video about SMD soldering is given above. Please watch it.

This is the last step in the PCB making. In this step we connecting all the necessary wires to the drilled holes in the PCB. The wires are used to connect all the four status LEDs, input and output (not connect wires to the Li-ion cell now). For connecting the power supply use color coded wires. For the wire connection first apply flux on the stripped wire end and in the PCB pad and then apply some solder to the stripped wire end. Then place the wire to the hole and solder it by apply some solder to it. By this method we create a good wire joint to the PCB. Doing the same procedure for all the rest of the wire connections. OK. So we done the wire connection. So our PCB making is almost over. In the following steps we going to made the cover for whole setup.

This is the starting step of cover making. We create the cover by using the black plastic name board. The cutting is done by using the hacksaw blade. We plan to place the Li-ion cell and the circuit board below the Arduino board. So we going to create a rectangular box with dimension slightly greater than the Arduino board. For this process, first we mark the Arduino dimension into the plastic sheet and draw the cutting lines slightly greater in dimension. Then cut the 6 pieces (6 sides) by using the hacksaw and double check, it is the correct dimension or not.

In this step we finish the plastic pieces edges by using the sandpaper. All the edges of each pieces is rubbed against the sandpaper and clean it. Also correct each pieces dimension in a precise manner in this method.

We creating a portable lab. So it need I/O pins and USB port accessible to the external world. So needed to make the holes in the plastic covering for these ports. So in this step we going to create the hole for the ports. Procedure is given below.

• First mark the I/O pin dimension (rectangular shape) in the top piece and mark the USB port dimension in the side piece

• Then remove the portion by drilling holes through the marked line (make holes inwards to the removed portion)

• Now we get a irregular shaped edges, this is roughly shaped by using the pliers

• Then finish the edges smooth by using small files

• Now we get a smooth hole for ports

• Clean the pieces

We need a switch for ON/OFF the portable Arduino lab and we have for status LEDs. So we fix it in the side opposite to the USB port. Here we use a small slide switch for this purpose.

• Mark the dimension of the switch in the plastic piece and also mark the position of the four LEDs above it

• By using drilling method remove the material in the switch portion

• Then it is finished to the switch shape by using files

• Check and ensure that the switch is fit in this hole

• Make hole for the LEDs (5mm dia.)

• Fix the switch in its position and screwed it to the plastic piece by using driller and screwdriver

Now we completed all the work in the pieces. So we connected it together to form the rectangular shape. For connecting all the pieces I use super glue (instant adhesive). Then wait for curing it and again apply glue for double the strength and wait for cure it. But one thing I forgotten to tell you, the top piece is not gluing now, only glue other 5 pieces.

We created the rectangular shaped box in the previous step. Now we place the Li-ion cell and the PCB at the bottom side of the enclosure by using double sided tape. The detailed procedure is given below.

• Cut two pieces of the double sided piece and stick it in the bottom side of the Li-ion cell and PCB

• Connect the +ve and -ve wires from the battery to the PCB in the wright position

• Stick it into the bottom side of the box as shown in the above images

In this step we connect the switch wires from the PCB to the switch. For a good wire connection, first apply some flux on the stripped wire end and in the switch legs. Then apply little bit solder on the wire end and in the switch leg. Then using tweezers and the soldering iron connect the wires to the switch. Now we done the work.

Here we going to connect all the status LEDs to the wires from the PCB. In the connection process ensure the right polarity. For each status I use different colors. You choose you favorite colors. The detailed procedure given below.

• Strip all the wire ends at required length and cut extra length of the LED legs

• Apply some flux to the wire end and to the LED legs

• Then apply some solder to the wire end and LED legs using soldering iron

• Then joint the LED and wire in the right polarity by soldering

• Place each LED to the holes

• Permanently fix the LED by using hot glue

• We done our work

This is our last circuit connection procedure. Here we connect our PCB with the Arduino. But there is a problem where we connect the PCB. In my search I find a solution myself. It is don't damage the Arduino board. In all Arduino Uno boards there is a safety fuse. I remove it and connect the PCB in between. So the power from the USB is directly going to our PCB only and the output 5V of PCB is going to the Arduino board. So we successfully connect the PCB and Arduino with out making any damage to the Arduino. The procedure is given below.

• Apply some flux to the Arduino fuse

• Using hot air gun and tweezers remove the fuse safely

• Strip the input, output wires of our PCB and solder its end

• Connect the ground (-ve) of input and output (our PCB) to the USB body ground using soldering iron (see in the images)

• Connect the input +ve (our PCB) to the fuse solder pad which is near to the USB (see in the images)

• Connect the output 5V +ve (our PCB) to the other fuse solder pad far from the USB (see in the images)

• Double check the polarity and connection

The last part which we not fitted is the Arduino. Here in this step we fitting the Arduino in this box. Before fixing the Arduino in the box, we take a plastic sheet and cut a piece which is suitable for the plastic box. First place the plastic sheet and then place the Arduino above to it. It is because the PCB which we made is situated below, So there need an insulating isolation between the PCB and the Arduino. Otherwise it cause short-circuit between our PCB and the Arduino board. The plastic sheet is protect from short-circuit. The completed images shown in above. Now switch on the power supply and check whether it is work or not.

Here we connect the last plastic piece, that is the top piece. All the other pieces are glued together but here the top piece is fit by using screws. Because for any maintenance we needed to access the PCBs. So I plan to fit the top piece using screws. So first I made some holes in the 4 sides using a driller with small drill bits. Then screwed it by using screwdriver with small screws. By this method fit all the 4 screws. Now we done almost all the work. The rest of the work is to increase the beauty of our portable lab. Because now the enclosure look is not good. So in the next steps we add some art works to improve the beauty. OK.

Not our plastic enclosure is not looks great. So we add some colored plastic stickers to it. I use the thin stickers which are used in vehicles. First I use an ash colored stickers for the 4 sides. First check the dimensions using a ruler and then cut the necessary holes for the switch, LEDS and USB. Then stick it in the side walls of the plastic enclosure. All the necessary images are shown above.

In this step stick the stickers in the rest of the top and bottom side. For this I use black stickers. First draw the dimension of the top and bottom side and then create the holes for the top ports and then stick it to the top and bottom side. Now I believe that it have a pretty decent look. You choose your favorite colors. OK.

In this step I use some art works to increase the beauty. First I add some yellow colored strips of plastic sticker through the sides of the I/O port. Then I add small blue strips through all the side edges. Then I made some blue colored round pieces by the use of paper punching machine and it add in the top side. Now my art work completed. You try to make better than me. OK.

This is the final step of our "Portable Arduino Lab" project. Here I made the Arduino symbol by using the same sticker material of blue color. Fist I draw the Arduino symbol in the sticker and the cut it by using scissors. Then I stick it to the center of the top side. Now it looks very beautiful. We completed our project. All the images show above.

The above images shows my finished product. This is very useful for everyone who like Arduino. I like it very much. This is an awesome product. What is your opinion? Please comment me.

If you like it please support me.

For more details about the circuit Please visit my BLOG page. Link given below.

https://0creativeengineering0.blogspot.com/

For more interesting projects, visit my YouTube, Instructables and Blog pages.

Thanks for visit my project page.

Bye. See you again........