Bit and pieces of android app development part 2 - DIY woodworking India

Bit and pieces of android app development part 2 - DIY woodworking India

Hey all! Welcome. Hope you have gone through the first part of bit and pieces of android app development. If not, here is the link. That part was kind of introductory. It was more about how to solve an existing problem with the means you already have! technically. After all, it is more about passion and motivation. If you really want to solve a real problem with your heart and soul, I know you will do it. For that reason, anything coming your way - may it be a new learning or a skill set, you will surely do it. Learning android app development is just an another dot in that context, but the diameter of that dot is huge.

Continuing the discussion from our last blog, let us put a high level use case of our application.

Pictures can convey the message more clearly. The app user 1 has encountered the pothole and the app has written the coordinates and timestamp into the local sqlite data base of the android phone. Time to time, the app will upload the data to the server. Lets assume, it has already uploaded the data. App user 2 is approaching the same pothole, but he will see in his app that there is a pothole nearby. The app will send him a cautious message in terms of a tone or an alarm. Does it sound good?

Lets draw a high level design of our application. It is little more technical. But I will explain it in simple language.

This is a flow chart of the application we are going to build.

START - implies the application has started.
LISTEN TO THE ACCELEROMETER - implies that inbuilt accelerometer of the android phone is reading the acceleration value in X,Y and Z direction.
VALUE > 15 - implies that acceleration in either direction is more than 15.
RECORD GEOGRAPHICAL COORDINATES INTO DB - implies that phone's sqlite DB table is updated with the coordinates.
SYNC DB TO CLOUD SERVER - implies that phone's DB is uploaded to cloud server and data are synced.

Y and N means Yes and No respectively. Below picture depicts multiple users using the app syncing their own DB with cloud.

So far so good. I hope the design is pretty clear now. Let me give you some more detail. Two more diagrams are listed below.

No sooner than I am writing this blog, I have completed the application. Let me give you a screenshot and the play store link.

Here is the link to the app.

https://play.google.com/store/apps/details?id=com.sbordolo.potholefinder

You can install the app and try it out. If you find any difficulty, please comment.

Till this point, it has been only requirements and designs. You may be looking for the coding, of course. That will follow shortly in subsequent pages. Stay tuned.

Thanks for visiting DIY woodworking India.

The making of the cajon drum - DIY woodworking India

DIY woodworking India - The making of the cajon drum

Welcome to DIY woodworking India. 

Figure:1

Figure:2

Figure:3

Figure:4

Hi friends! Welcome to my small world of carpentry - DIY woodworking India. I have developed woodwork as my free time venture starting from mid 2013. It was exciting, new and there were lots of things to learn from carpenters, internet and many other sources! Although I did some wood work in my childhood days probably 20 years back, it was different in the recent times with a few tools I have purchased online.

To begin with, I took up a small project of making a musical instrument called - CAJON. It is a drum with snares installed inside. One face is used for slapping the music beat. 

Tools used: 

1. Jig saw 

2. Driller 

3. Hammer

4. Sand paper

Raw materials:

1. Plywood - a) 8mm thick. b) 4 mm thick(ply embedded with laminate will be better) 

2. Nails 

3. glue(Fevicol speed x)

4. Guitar tuning head

5. Snare - used in drum kit

6. 2x1 inch wood pieces for the inside support carcass 

It is very important to have the plan right in the beginning. If the plan has defects, it will cost you wasting more time towards the end in filing, finishing etc. 

The plan:

All the dimension below will be in inch.

1) 20x12 - 8 mm - 2 pieces

2) 12x12 - 8 mm - 2 pieces

3) 20x12 - 4 mm - 2 pieces

Figure: 5

The carcass should be such that it fits the main body of the cajon.

Steps:

1) Cut the 2x1 pieces based on the drawing cited above. I am assuming that you have basic knowledge about the wood joinery. To know more about it, please refer my other blogs on that topic. The famous mortise and tenon joint is shown below.

2) Keep a slot for fitting of the snare wires. It should be such that from that slot, it touches the slapping surface. Fit the snares using screws/nails whichever way is suitable for you.

3) Refer the figure above to understand how the carcass looks like. Snare is pulled by a string(strong thread will also do) which is connected to the guitar tuning head peg. So, when you tighten the head, snare will lean more into the slapping surface thereby you will get more snare effects. You loosen it, there will be less snare effect.

Here is a video which was captured during the making.

4) Once it is ready, it is time to fix the surfaces. Refer to figure 1 to 4 to get an idea how they are fixed. Front surface displayed in the figures are slapping surface. The opposite one has a hole in it for resonating effect. Refer below diagram. All the surfaces apart from the front are fixed with glue + screws. The front surface is fixed with screws primarily because you can tighten/loosen the screws to have different sound.

Figure: 6

5) Once done, it is time to fix the sitting cushion. I have used a piece of yoga mat for the purpose.

You are all done now. Enjoy playing your DIY cajon drum.

Thank you for visiting DIY woodworking India. 

Thankfully,
Sarang