Final Grad Book Text + Images

Haptic Proximity Module

‘Low vision’ (LV) is a common form of vision impairment that involves irreversible vision loss – significantly reduced vision but not total blindness and hence still usable vision – affecting 246 million people globally.

The project aims to develop an open-source haptic proximity module (HPM) costing approximately $50, which will enable LV users to engage with their direct environment via interactive touch as a measure of closeness. This contributes to the discourse on wearable assistive technology while incorporating off-the-shelf components to create an accessible ‘do-it-yourself’ project.

After conducting a study of LV, its effects on an individual’s functional independence and available assistive technologies, the project’s findings show that people with LV are still reasonably independent within the home, but outside the home this independence begins to deteriorate. The available products are expensive and narrow in application, lacking cheap and readily available haptic devices that extend a LV user’s perception of their immediate surroundings.

The outcomes of this research explore how these findings can be addressed to positively impact on the interaction of LV users with their surroundings. The larger goal of enabling a broader LV user group is then achieved through developing low cost HPMs.

 

Grad Book Abstract [Draft 01]

Haptic Proximity Module:Open Source Assistive Technology for the Vision Impaired

Title Count: 11 words

Abstract:

Low Vision (LV) is a form of vision impairment that involves irreversible vision loss; it is significantly reduced vision but not blindness and is still usable vision. According to the World Health Organisation, LV affects 246 million people worldwide and their Quality of Life.

The findings of a study of LV, its effects on an individual’s functional independence and available assistive technologies, showed that:

  • People with LV are still reasonably independent within the home, albeit with learned coping methods, however, outside of the home this independence begins to deteriorate.
  • Available products are either too expensive and are specific in application; there are no cheap and readily available haptic device that extended a LV user’s perception of distance and objects within their surrounding.

How can both of these findings be addressed to positively impact the interaction of a LV user with their surroundings?

Development of an open-source Haptic Proximity Module (HPM) began with the intention of enabling a LV user to engage their immediate environment for approximately $50 AUD. This approach incorporates off-the-shelf components and can be acquired as a DIY kit or pre-assembled unit, while contributing to the discourse on wearable assistive technologies (AT).

Abstract Count: 196 words

Keywords: Assistive Technology (AT), Do-It-Yourself (DIY), Low Vision (LV), Haptic Proximity Module (HPM).

Keywords Count: 12 words

 

Further debugging with BELT_02 code

I created a testing rig with 2 Sensor+Motor+LED groups to test this code. At first they worked well and as expected. Then I decided to add another sensor+motor+LED group. The outcome did not follow the initial test with two groups. The set-up seemed to struggle as there seemed to be a power problem.

Like with the belt test, there was one group that was seemingly vibrating on its own. Potentially there is a need to isolate the power to the motos, or experiment with different code. As my coding skills are weak, I cannot see how I can modify my code further to solve this problem.

From this point, I will also begin to CAD and create what I need for an module.

HPB first wear/test

Using BELT_02 code I managed to get all four sensors and motors to work, as I realised my error with my initial attempt (failing to map all values of distance and power).

There are 4 sensor and motor combinations/groups, I labeled them FL, BL, FR, BR. [F = front; B = back; L = left; R = right]. The coupling/mapping was direct – vibration was coming from the point of distance detection.

Initially FR was only sensing and vibrating, after the code review and update all 4 groups were sensing and vibrating. However, only the BR motor kept vibrating the most and consistently. I also noticed a considerable delay when each sensor was activated.

The vibration strength varied based on the shroud’s effectiveness – the shrouds were made from straws with the motors inserted into them, this is low cost and fast way to allow the asymmetrical weight rotate. In effect the shrouds were failing and not allowing the motors to rotate, thus preventing any form of vibration. 

The code and potentially the wiring needs further debugging. I’m using jumper cables left right and centre! which is fine for a quick and dirty prototype but very messy when trying to debug. If time allows, a revisiting of the code and custom connectors/lengths of wire to make it work better and neater. 

I will revisit the Project HALO code from Instructables and see what I can do with that, I believe it deals with the sensing and motors in more of a clock fashion. Power seems to be another issue I’m facing. So far I’ve connected a battery directly to the Arduino Mega 2560, but Project HALO advises this: 

“a 5v regulator is connected to the 9v terminals and this is sent to drive the Darlington IC (and in turn, the motors) so we have 2 power systems and the Arduino is isolated”

 

Parts list:

  • Arduino Mega 2560
  • 3v Vibration Motors: 256382 from Jameco.com
  • HC-SR04 Ping Sensors
  • Bread board
  • Development Shield for Arduino Mega
  • Custom 4-to-3 connectors
  • Zip-ties
  • Electrical/Duct tape
  • Velcro Tape
  • Male-to-Female, Female-to-Female, Male-to-Male jumpers 
  • Old belt

 

More to come…