It is hard to believe that the time for this project is already over, but I am glad that I was able to finish everything on time. I have posted some of the final pictures of the Glove below, and I will either post more pictures or try to get a video of it working. Most of the wires will be hidden under the cover that I wrote about on Post 1 of Week 8, but I didn’t take the pictures with it on. Other than that, hopefully you will like what you see…

Also, in case you didn’t see it already, the final proposal is on the Pages section under Final NSCS $15,000 Grant Proposal.

PICTURES

PROGRESS

In the past few days, I have further modified the power supply that I will be using to power my components, and have continued to prepare the wires for their final connection to the sensors. I have also decided that the circuit board will sit on the glove itself, most likely where the glove’s strap is located. I have attached a second circuit board to the original board with all the components, resembling two stories of boards with enough clearance between the two. The bottom board is to protect the connections of the top one from being damaged by direct contact to the glove. The bottom board will then be attached to the glove by a strip of velcro, making the board removable and easier to maintain.

I will be starting to write the proposal for the final stage tomorrow, and will post it as soon as it is ready.

The pictures are coming soon…

PROGRESS

This weekend I finished a little power supply that will take a 9V DC battery voltage and regulate it down to 5 V. This will power the PIC, the LCD screen, the TTS module, etc. I have included a switch as well, to let me turn the power on and off instead of having to connect and disconnect the battery each time. The power supply will go in the back of the speaker box. I have also been working on the connections between the wires and the sensors. I have soldered pins to the end of the wires, so that these pins can be plugged straight in to the sensors. I soldered the accelerometer to a little mini-board, and this board will be mounted on the top of the hand. I will try to get some pictures of this to help give a better idea of what is going on.

]]> http://ejvivanco.wordpress.com/2009/07/20/post-2-week-8-july-13-%e2%80%93-july-19/feed/ 0 ejvivanco http://ejvivanco.wordpress.com/2009/07/15/post-1-week-8-july-13-%e2%80%93-july-19/ http://ejvivanco.wordpress.com/2009/07/15/post-1-week-8-july-13-%e2%80%93-july-19/#comments Thu, 16 Jul 2009 02:57:09 +0000 ejvivanco http://ejvivanco.wordpress.com/?p=352 ]]> Wednesday, 7/15/09

PROGRESS

Here are the pictures that I have promised. The first two are of the circuit board with the new additions. You will see more wires for the sensors, wires for the accelerometer, sockets for the wires coming from the LCD screen and TTS (text-to-speech) module, and a potentiometer in order to control the contrast of the LCD display. The potentiometer is the small blue rectangle on the bottom right of the board.

The next picture is of the sleeve that will hold the touch sensor that goes on the thumbnail in order to help recognize the letter ‘E’. The next sleeve picture is one for the sensor on the other side of the thumb for the letter ‘O’. The third picture is for the sleeve that sits on the left side of the middle finger. The touch sensor that goes here will be used to determine if the gesture being signed is ‘U’ or ‘V’.

If you want a little challenge, go to my AMA Glove Reference Material Page, and by looking at the chart, see if you can reason why the sensor locations that I mentioned in the previous paragraph would help to differentiate these gestures from others.

The last two pictures show a little cover that I made for purely cosmetic reasons. I just wanted to have something to keep the sensors from being in plain sight and to maybe protect them from the elements of nature. The first one shows the actual size of the cover, but after it is bent around the glove, it would look like the last picture.

PICTURES

PROGRESS

This week I have  continued adding components to the circuit, and will post pictures of the progress as soon as I get the chance. I have been working on how the sensors will be placed on the glove, and sewing the sleeves that will hold some of them in place.  I have also been working on the programming code that I will need to make this project work. The programming is very tedious and repetetive, you have to test and try, test and try, etc. What I am doing is obtaining the sensor output on the LCD screen, and then using that value to make if statements for the final code. In the end, if the conditions for the if statements are met, then it will produce the programmed output, which in my case will be a letter of the alphabet.

This is a brief example of one of my statements.

if((pointer>190) && (pointer<230) && (middle>260) && (ring<340))

{

LCD_Custom_out(2, 8, “C “);

}

This letter C will only be output on the LCD screen if the conditions next to the if statements are met. If the sensor on the pointer finger shows a value between 190 and 230, the middle finger sensor shows greater than 260, and the ring finger sensor shows less than 340, then the LCD will show the letter C. The actual code is more involved, but this simple example should help one to understand the process in determining the correct gesture being signed by the user.

PROGRESS

Apart from working on the sensor sleeves on the glove, I have continued to solder more components to the circuit board. The newest additions are the back to back 10 kΩ resistors and the black and white wires. The resistors, which are designated by the  brown, black, and orange stripes, are each part of the circuit that will connect to the sensors.  They help to form the voltage divider circuits that I metioned in one of the previous posts. The black and white wires will form the actual connection to the sensors.

PICTURES

PROGRESS

I have started to work on fitting the sensors to the glove. I have cut little openings on the glove where each finger connects to the hand, so that the flex sensor going inside of each sleeve can come out of this opening and connect itself to the wires that will interface them to the PIC. This means that the flex sensors will be for the most part out of sight, because they will be under each sleeve and will only be exposed for the actual connection. I am currently working on sewing the sleeves that will hold the touch sensors that will sit on the proximal phalanx of each finger. You can look up what part of the finger this is in the AMA Glove Reference Material Page, it will be the second picture.

PROGRESS

I posted three more pictures on last week’s post, trying to show my setup and how the LCD displays the value output from the PIC. I tried to make a video, but the quality was terrible because of bad lighting. I will try to get it working on film again today, hopefully it comes out better. In the video you will see how the numerical value representing the voltage seen by one of the PIC input pins, changes as I bend the flex sensor, or as I press the touch sensor, depending which one I use for the video.

PROGRESS

Since last week, I have finished soldering the capacitors and oscillators to the board, and have begun to work with the sensors and their corresponding numerical output values. I am still using the breadboard for this testing phase, and once I am happy with the results, (and find the wires that I need), will begin to solder the sensors to the board through those wires. I connected one of the flex sensors to the PIC, and wrote a simple program to have the PIC display a numerical value based on the output of the sensor. That value will be shown on the LCD screen of the box that I built last week.

The way this works is with the concept of a voltage divider. In electronics, a voltage divider is a simple circuit that produces an output voltage that is a fraction of its input voltage. That fraction depends on the values of the resistors in the circuit. The circuit and corresponding output voltage equation are as follows.

In the pictures, you will see that I took a screenshot of my computer while I was testing out the PIC on the breadboard for the first time. The window in the background is the compiler, which is where I write and troubleshoot the code for the PIC. The small window on the right is the PICkit programmer, which lets me download the compiled program to the actual chip. That specific code in the window turns on an LED that I connected to one of the pins on the PIC. This was just to make sure that everything was running properly, which it did.

I will try to post more pictures this weekend.

PICTURES

Screenshot…

Breadboard and LCD/ Speaker Box…

Testing display…

A little closer…

PROGRESS

The final components for the microcontroller circuit finally came in, so I was able to finish soldering them tonight. In the pictures, you will see the small blue capacitors and the silver crystal oscillator on the left side of the PIC socket. The oscillator serves as an external clock for the PIC. The clock is a periodic waveform, which means that it repeats the exact same shape again and again. This clock is used as a synchronizing signal that is used to execute the instructions and commands of the program code. Think of it as the heartbeat to the microcontroller, so without it, the system would cease to function.

The PIC has a built-in oscillator, but the external oscillator lets you achieve much higher frequencies, which results in faster operation. The external oscillator frequency is 10 MHz, which means there is 10 million cycles per second. The PIC also has a 8x PLL, or phase locked loop circuit, which multiplies the external oscillator frequency by 8. This means that my PIC will be running at a total of 80 MHz, or 80 million cycles per second. Fast, right?

I posted another link in the Electrical/Electronics Theory Links Page as well. It is to a pdf called Microcontroller Programming – The Microchip PIC. It should help to understand anything you might want to know about electronics, circuits, microcontrollers, etc.

This coming week I will finish soldering the connections of the components that I have so far, and will give the PIC a test run to make sure everything is correct.

In the pictures, you will see that I set up a circuit on my breadboard just to make sure that the PIC and sensors work. The green LED on the right will be lit up whenever there is power being delivered to the PIC, so it serves as a reminder that the circuit is on. The next picture shows that when the flex sensor is hardly bent, the resistance is large, shown by the multi-meter as 57.5 kΩ, which is 57,500 ohms. The second picture shows the resistance measured as 9.7 kΩ when the sensor is bent almost 90 degrees.

I also posted two videos on youtube to show the sensors in action. Please forgive me on the poor video quality, I had to use the camera on my phone…

The first video shows the flex sensor controlling the brightness of the red LED. When the sensor is not bent, the resistance is very large, so there is not enough power being delivered to light up the LED. As I bend the sensor, the resistance goes down, turns on the LED, and increases the brightness correspondingly.

The second video shows the touch sensor as the means to controlling the LED.

PICTURES

Circuit on breadboard to check PIC and sensors…

Sensor showing large resistance…

Sensor showing low resistance…