Interactive maps for visually impaired

We constructed 3d-printed box. We use some ready construction parts – battery boxes RUICHI 84*44*18 mm, only for versions with 6 AAA batteries as power supply.

Battery boxes RUICHI 84*44*18 mm

We used Anycubic Max4 3d printer with 210 x 210 print field.

Fig. 7 Box Rendering. Inset – box for Ultrasonic Sensor. We made box from 6 parts- left and right sides with loudspeaker holders, bottom left with holders for batteries boxes, bottom right with holders for PCBs, back side with holders for amplifier, switch and button, and front panel with slot for USB cable. We include *.stl files. 

Let us show the schematics. We use microcontroller PCB Arduino Nano R3.0 with Atmega328PU chip on board, but You can use any kind of Arduino IDE- compatible board. We decide to use Arduino IDE and Arduino boot on chip to make programming easy.

We use HC-SR04 Ultrasonic sensor to detect the motion near the Map to switch the Map in the work mode and vice versa. When HC-SR04 feels some in 20-30 cm the controller make the invitation “You can press or pull up any continent out of the map”. We use some delay (30-120 seconds) to avoid frequent repetition of the invitation. The delay timer is reset every time someone touches the touch pads.

We install metal screws M2 (it can be any convenient metal construction as rivet) in continents, and small D8x3 mm magnets. Continents with inserted metal screws are attracted to the magnets. We glued wires to magnets and connect wires to the sensor pad chip Proximity Capacities Touch Sensor Controller MPR121. Four MPR121 can be connected to the one controller by I2C bus. We use only two. Chip in MPR121 board measure the charge flow, and when the charge flow via pin is big enough the chip reports to the Arduino via I2C bus that someone touch or untouch the pad. If the pud is touched the Arduino sends command to MP3 Player via Tx bus, and the MP3 Player plays the file. Button S2 switch the mode of the Map- geography, topology, culture, economy, folklore of the continent or island. Stereo signal from MP3 Player go to the stereo amplifier PAM8610 with volume control. Two speakers are connected. We use 5V powerbank or 6 AA accumulator (6x1.2=7.2 V) and DCDC converter to 12 V XL6006. 

West hemisphere map with continents, the biggest islands and of equator, tropics, polar circles. You can take off continents to touch it. We used very bright colors because some visually impaired people can see some shadows of contours and colors.

We attach the files for 3D printers:

V1_Eurasia.stl – Continent Eurasia

V1_Islands.stl - Islands

V1_NorthAm.stl – Continent North America

V1_Other.stl  – Other Continents

SemEast.stl – East Hemisphere

SemWest.stl – West Hemisphere

We use 0.375 mm offset for continents and Hemispheres – this mean that it is a gap 0.375 mm along the countour, and continents and islands can be easy placed and taken out.

We constract and test the schematics of the device. We use break bord MRP -121. The Board can be used for 12 sensor touch pad.

We added two filew- west and east hemispheres with grooves for continents  and with the curves of the equator, tropics, polar circles -  SemEast.stl and  SemWest.stl  .  The files are on the github.

We print the maps with the slots on the continents places, and we print the continent and the biggest islands, using 0.375 mm offset. 

We made contour map on the graph paper using single map and made our contour point by point, counting the coordinates of contours. Thus we have some point arrays. We paste the arrays in 3d- CAD program. We add the curves of the equator, tropics, polar circles.