A Touch of Light

A step towards enlightenment for those living in the world of darkness.

A Young India Fellowship Initiative in collaboration with University of Pennsylvania


      





Sunday, March 25, 2012

viSparsh Intro

viSparsh Experience at TechEd2012

viSparsh Prototype 2




We have finally been able to come up with the 2nd prototype of the belt as shown in the pic. Although, the size of the belt still looks similar to the previous version, we have done some major technical upgradations in the belt. The belt has now more robust power management system with single ON-OFF button and less components. Previous post provides the list of changes in this new prototype.
After making it functionally robust, our next aim is to decrease the size of the belt.



In the next version, we are trying to make a sleek design by considering various possibilities like replacing bigger PandaBoard with small BeagleBone, removing Kinect's plastic casing to use only the required components etc.
One of our main focus at present is to build a sleek design before adding more functionalities.




viSparsh @ TechEd2012


All ready with the second prototype of the belt, we showcased viSparsh at the TechEd2012 held at Bengaluru from 21st to 23rd March 2012.
TechEd is Microsoft's annual event to showcase state of the art technologies. We were given a booth to demonstrate our prototype.
This second prototype of the belt has following upgradations
- Less Bulky due to replacement of twelve 1.2V batteries with single 3 cell LiPo Battery.
- Single switch On-Off belt
- One major component mbed removed by directly running vibration motor through PandaBoard.
- Voltage Cut-off circuit integrated to prevent battery from damaging.
- Better Haptic feedback using the new vibration motors.

It was a fantastic experience demonstrating our project in such a big platform. The project was highly appreciated by the industry experts and others who visited the event.


Better Haptic Feedback using new vibration motors

In our first prototype of the belt, we were using ROB 08449 buzzers (left side of the image) to give haptic feedback to the visually impaired people.
The vibrations produced by them were perpendicular to axes of the belt and thus got significantly reduced as we taped them inside the belt. Therefore, we needed more powerful vibration motors for our purpose.
We have replaced the current motors with Pico Vibe 9mm Vibration Motor- 25mm type (RHS of the image) as it provides vibrations both in X and Y planes.
As could be seen in the pic, they are slightly bigger in size (25mm length and 8.8mm diameter) compared to 3.4 mm length of ROB-08449 motors. However, both operate at 3V and Pico Vibe produces 13,500rpm speed compared to 12000rpm of ROB-08449 buzzers. This is a significant improvement as our output depends on the efficiency of these vibrations. Further, instead of earlier 6 motors, we now have to use only 3 motors in the belt ( one for each zone- left, centre and right).

mbed Removed

We have finally succeeded in removing one major component from the belt. The initial design of the belt had mbed in it. We were using mbed to generate PWM (Pulse width Modulation) to be sent to the actuators (vibration motors in our case). However, we eventually figured out that the same functionalities can be provided by PandaBoard without incurring that extra component cost of mbed.

PandaBoard has on-board GPIO (General Purpose Input Output) pins that can be used to render multiple functionalities. We configured three GPIO pins as output and created three software threads to generate variable-duty PWM. This PWM further actuates the vibration motors to guide the visually impaired in obstacle-detection.

Removal of mbed is a major breakthrough for us as we are continuously working on decreasing the size of the belt to make a sleek wearable design.

Belt with 'Single Switch ON-OFF' feature


In line with the continuous up-gradations being done in the belt, the next is making the belt start with the press of a single button. The circuit deploys DPDT (Double Pole, Double Throw) switch along with the power cut-off circuit.
It now takes away the burden of making power connections everytime one had to wear the belt.


Belt upgraded with new Power Circuit


Power issues have been bothering us for quite some time. We were earlier using 4*1.2V batteries to power PandaBoard and mbed and 8*1.2 V for Kinect. This had made the design quite bulky and was taking unnecessary space. Thus, we decided to reduce the size by replacing these cells with 2000mAh, 3 cell LiPo battery which gives 11.1V. The pic above shows the integrated LiPo batteries in the belt.
Further, we have implemented the Power Cut Off Circuit to prevent 3 cell LiPo batteries from damaging whenever voltage drops below 9V.

We have built the voltage cut off circuit using details given in RC forum
The pic shows the implemented circuit.

Sunday, March 25, 2012

viSparsh Intro

viSparsh Experience at TechEd2012

viSparsh Prototype 2




We have finally been able to come up with the 2nd prototype of the belt as shown in the pic. Although, the size of the belt still looks similar to the previous version, we have done some major technical upgradations in the belt. The belt has now more robust power management system with single ON-OFF button and less components. Previous post provides the list of changes in this new prototype.
After making it functionally robust, our next aim is to decrease the size of the belt.



In the next version, we are trying to make a sleek design by considering various possibilities like replacing bigger PandaBoard with small BeagleBone, removing Kinect's plastic casing to use only the required components etc.
One of our main focus at present is to build a sleek design before adding more functionalities.




viSparsh @ TechEd2012


All ready with the second prototype of the belt, we showcased viSparsh at the TechEd2012 held at Bengaluru from 21st to 23rd March 2012.
TechEd is Microsoft's annual event to showcase state of the art technologies. We were given a booth to demonstrate our prototype.
This second prototype of the belt has following upgradations
- Less Bulky due to replacement of twelve 1.2V batteries with single 3 cell LiPo Battery.
- Single switch On-Off belt
- One major component mbed removed by directly running vibration motor through PandaBoard.
- Voltage Cut-off circuit integrated to prevent battery from damaging.
- Better Haptic feedback using the new vibration motors.

It was a fantastic experience demonstrating our project in such a big platform. The project was highly appreciated by the industry experts and others who visited the event.


Better Haptic Feedback using new vibration motors

In our first prototype of the belt, we were using ROB 08449 buzzers (left side of the image) to give haptic feedback to the visually impaired people.
The vibrations produced by them were perpendicular to axes of the belt and thus got significantly reduced as we taped them inside the belt. Therefore, we needed more powerful vibration motors for our purpose.
We have replaced the current motors with Pico Vibe 9mm Vibration Motor- 25mm type (RHS of the image) as it provides vibrations both in X and Y planes.
As could be seen in the pic, they are slightly bigger in size (25mm length and 8.8mm diameter) compared to 3.4 mm length of ROB-08449 motors. However, both operate at 3V and Pico Vibe produces 13,500rpm speed compared to 12000rpm of ROB-08449 buzzers. This is a significant improvement as our output depends on the efficiency of these vibrations. Further, instead of earlier 6 motors, we now have to use only 3 motors in the belt ( one for each zone- left, centre and right).

mbed Removed

We have finally succeeded in removing one major component from the belt. The initial design of the belt had mbed in it. We were using mbed to generate PWM (Pulse width Modulation) to be sent to the actuators (vibration motors in our case). However, we eventually figured out that the same functionalities can be provided by PandaBoard without incurring that extra component cost of mbed.

PandaBoard has on-board GPIO (General Purpose Input Output) pins that can be used to render multiple functionalities. We configured three GPIO pins as output and created three software threads to generate variable-duty PWM. This PWM further actuates the vibration motors to guide the visually impaired in obstacle-detection.

Removal of mbed is a major breakthrough for us as we are continuously working on decreasing the size of the belt to make a sleek wearable design.

Belt with 'Single Switch ON-OFF' feature


In line with the continuous up-gradations being done in the belt, the next is making the belt start with the press of a single button. The circuit deploys DPDT (Double Pole, Double Throw) switch along with the power cut-off circuit.
It now takes away the burden of making power connections everytime one had to wear the belt.


Belt upgraded with new Power Circuit


Power issues have been bothering us for quite some time. We were earlier using 4*1.2V batteries to power PandaBoard and mbed and 8*1.2 V for Kinect. This had made the design quite bulky and was taking unnecessary space. Thus, we decided to reduce the size by replacing these cells with 2000mAh, 3 cell LiPo battery which gives 11.1V. The pic above shows the integrated LiPo batteries in the belt.
Further, we have implemented the Power Cut Off Circuit to prevent 3 cell LiPo batteries from damaging whenever voltage drops below 9V.

We have built the voltage cut off circuit using details given in RC forum
The pic shows the implemented circuit.