What is a Braille KeyPad ?

• Braille KeyPad is a Bluetooth keyboard with a special layout that allows visually impaired individuals to easily navigate and type into SmartPhones and tablets.
• There are 6 circular Braille input buttons on KeyPad arranged in a braille layout. By pressing combinations of the braille input buttons you can input text and symbols. Braille text input is compliant to UEB Grade 1 and Grade 2 braille except non-ASCII characters and some lower groupsigns & wordsigns.

Physical Leyout:

• The braille keypads is a rectangular slab with rounded edges. It has all the buttons on one side, and is flat on the other.
• There is a slot for lanyard/wrist straps on one side of the rectangle.
• Braille KeyPad consists of 6 circular "Braille" keys, 5 square "Special Keys" and a 5-Way Navigation stick with Center click.
• The 6 circular braille keys are used to input text and symbols by brailling in UEB grade 1 and grade 2 braille, in addition to long pressing the braille buttons of certain alphabets to trigger shortcuts on the SmartPhone/Tablet
• The 5 square keys are Alt, Ctrl, Shift, Space & Delete keys.
• The Navigation stick controls up, Down, Left, and Right.
• Clicking the center of the navigation stick represents enter/newline
• The bottom os the device has the ON/OFF slider and the USB Charging input.

How to use

• Braille KeyPad is held between your palms, with the buttons facing away, and the flat side towards you.

Implementation:

How the HID Keypad is implemented for use with Braille

Grade 1 Braille

The Braille Alphabet—Internationally Standardised The letters a-z are common and standard for most braille country tables.

Grade 1 braille is a letter-for-letter substitution of its printed counterpart. This is the preferred code for beginners because it allows people to get familiar with, and recognize different aspects of, the code while learning how to read braille.

English grade 1 braille consists of the 26 standard letters of the alphabet as well as punctuation.

Charecters

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
letter sign	⠰	56
a	⠁	1
b	⠃	12
c	⠉	14
d	⠙	145
e	⠑	15
f	⠋	124
g	⠛	1245
h	⠓	125
i	⠊	24
j	⠚	245
k	⠅	13
l	⠇	123
m	⠍	134
n	⠝	1345
o	⠕	135
p	⠏	1234
q	⠟	12345
r	⠗	1235
s	⠎	234
t	⠞	2345
u	⠥	136
v	⠧	1236
w	⠺	2456
x	⠭	1346
y	⠽	13456
z	⠵	1356

Numbers

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
number indicator	⠼	3456
1	⠼⠁	3456 1
2	⠼⠃	3456 12
3	⠼⠉	3456 14
4	⠼⠙	3456 145
5	⠼⠑	3456 15
6	⠼⠋	3456 124
7	⠼⠛	3456 1245
8	⠼⠓	3456 125
9	⠼⠊	3456 24
0	⠼⠚	3456 245

The number indicator (⠼) is placed before the first digit in a group. Space, hyphen, grade 1 indicator or clears it

Example:

100: 	⠼⠁⠚⠚

using Grade 1 indicator/Letter sign (⠰) to specify end of number
221b:	⠼⠃⠃⠁⠰⠃

Punctuation

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
,	⠂	2
;	⠆	23
:	⠒	25
.(Period)	⠲	256
?	⠦	236
!	⠖	235
apostrophe '	⠄	3
quote "	⠴	356
hyphen -	⠤	36

Symbols

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
&	⠈⠯	4 12346
*	⠐⠔	5 35
#	⠸⠹	456 1456
@	⠈⠁	4 1
%	⠨⠴	46 356
+	⠐⠖	5 235
− (minus)	⠐⠤	5 36
=	⠐⠶	5 2356
~	⠈⠔	4 35
`	⠘⠡	45 16
^	⠈⠢	4 26
Underscore _	⠨⠤	46 36
Verical Line	⠸⠳	456 1256
/	⠸⠌	456 34
\	⠸⠡	456 16
(	⠐⠣	5 126
)	⠐⠜	5 345
[	⠨⠣	46 126
]	⠨⠜	46 345
{	⠸⠣	456 126
}	⠸⠜	456 345
<	⠈⠣	4 126
>	⠈⠜	4 345
$	⠈⠎	4 234
"	⠠⠶	6 2346

Indicators

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
number indicator	⠼	3456
grade 1 letter indicator	⠰	56
grade 1 word indicator	⠰⠰	56 56
grade 1 lock indicator	⠰⠰⠰	56 56
grade 1 terminator indicator	⠰⠄	56 3
capital letter indicator	⠠	6
capital word indicator	⠠⠠	6 6
capital lock indicator	⠠⠠⠠	6 6 6
capital terminator indicator	⠠⠄	6 3

The capital(ization) sign ⠠ marks the first letter of a word as capitalized. 
It may occur in the middle of a word for camel case, as in the name deAngelo. 
It is doubled to place a word in all caps; this must be repeated for each word of an all-cap text.
Use ⠠⠠ to Capitalise proceeding charecter, ⠠⠠ to Capitalise a full word,
⠠⠠⠠ to capitalise a full passage and ⠠⠄ to terminate. Using space/hyphen 
etc resets to normal unless not using paragraph caps. 
Warning: ⠠⠺⠁⠗⠝⠊⠝⠛
WARNING: ⠠⠠⠺⠁⠗⠝⠊⠝⠛

Note: The letter sign (grade 1 symbol indicator) ⠰ is used to force the end of a series of numbers.
For example, ⠙⠁ ⟨da⟩ preceded by a number sign, ⠼⠙⠁, is read as 41. 
If instead 4a is intended (as in a section or apartment number), 
then the letter sign is used to force a reading of a rather than 1 for the final character: ⠼⠙⠰⠁ ⟨4a⟩.

It is also used to mark a character as standing for a letter rather than for a word. For example, ⠃ ⟨b⟩ on its own is normally read as the word but;
to indicate that it is instead the letter b, the letter sign is used: ⠰⠃ b. Plurals of letters (mind your ps and qs)
always use an apostrophe in braille, but other derivations may not, as in ⠰⠝⠹ nth [time]: ⠠⠎⠬ is Sing, ⠰⠠⠎⠬ is S-ing/Essing. The letter sign is also used to mark lower-case Roman numbers, as in ⠰⠊⠊⠊ ⟨iii⟩.

Grade 2 Braille

The literary braille code, grade 2, uses “contractions” that substitute shorter sequences for the full spelling of commonly-occurring letter groups. The contractions are similar to English print contractions, like “cannot” versus “can’t”, in the way that a word is shortened. For example, “the” is usually a single character in braille. Grade 2 braille is the most commonly used form of braille code and is found in books, public signage, and restaurant menus to name a few. It consists of the 26 standard letters of the alphabet, punctuation, and contractions.

letter sign  (⠰) used to mark a character as standing for a letter rather than for a word. For example,
 ⠃ ⟨b⟩ on its own is normally read as the word but; to indicate that it is instead the letter b, 
the letter sign is used: ⠰⠃ b. Plurals of letters (mind your ps and qs) always use an apostrophe in braille,
but other derivations may not, as in ⠰⠝⠹ nth [time]: ⠠⠎⠬ is Sing, ⠰⠠⠎⠬ is S-ing/Essing.[27] The letter sign 
is also used to mark lower-case Roman numbers, as in ⠰⠊⠊⠊ ⟨iii⟩.

Alphabetic Wordsigns

CHARACTER	WORD	BRAILLE	BRAILLE DOT/BUTTON #
b	but	⠃	12
c	can	⠉	14
d	do	⠙	145
e	every	⠑	15
f	from	⠋	124
g	go	⠛	1245
h	have	⠓	125
j	just	⠚	245
k	knowledge	⠅	13
l	like	⠇	123
m	more	⠍	134
n	not	⠝	1345
p	people	⠏	1234
q	quite	⠟	12345
r	rather	⠗	1235
s	so	⠎	234
t	that	⠞	2345
u	us	⠥	136
v	very	⠧	1236
w	will	⠺	2456
x	it	⠭	1346
y	you	⠽	13456
z	as	⠵	1356

Strong Contractions (Part and Whole Word)

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
and	⠯	12346
for	⠿	123456
of	⠷	12356
the	⠮	2346
with	⠾	23456

Strong Wordsigns

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
child	⠡	16
shall	⠩	146
this	⠹	1456
which	⠱	156
out	⠳	1256
still	⠌	34

isStandingAlone?

Strong Groupsigns

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #	Note
-ch-	⠡	16	Letter join on either side
-sh-	⠩	146	Letter join on either side
-th-	⠹	1456	Letter join on either side
-wh-	⠱	156	Letter join on either side
-ou-	⠳	1256	Letter join on either side
-st-	⠌	34	Letter join on either side
------	----------------	----	-------------------------
gh	⠣	126
ed	⠫	1246
er	⠻	12456
ow	⠪	246
ar	⠜	345
-ing	⠬	346	Letter join on one side only, cannot be used to start a word

Lower Groupsigns

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #	Note
-ea-	⠂	2	Letters join on both side
-bb-	⠆	23	Letters join on both side
-cc-	⠒	25	Letters join on both side
-ff-	⠖	235	Letters join on both side
-gg-	⠶	2356	Letters join on both side
------	----------------	----	-------------------------
be-	⠆	23
con-	⠒	25	Letters join on one side only
dis-	⠲	256	Letters join on one side only
-en-	⠢	26	Letter join on either side
in	⠔	35

Lower Wordsigns

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
be	⠆	23
enough	⠢	26
were	⠶	2356
his	⠦	236
in	⠔	35
was	⠴	356

Initial Letter Contractions

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
day		5 145
ever		5 15
father		5 124
here		5 125
know		5 13
lord		5 123
mother		5 134
name		5 1345
one		5 135
part		5 1234
question		5 12345
right		5 1235
some		5 234
time		5 2345
under		5 136
work		5 2456
young		5 13456
there		5 2346
character		5 16
through		5 1456
where		5 156
ought		5 1256
upon		45 136
word		45 2456
these		45 2346
those		45 1456
whose		45 156
cannot		456 14
had		456 125
many		456 134
spirit		456 234
world		456 2456
their		456 2346

final Letter Groupsigns

CHARACTER	BRAILLE	BRAILLE DOT/BUTTON #
ound		46 145
ance		46 15
sion		46 1345
less		46 234
ount		46 2345
ence		56 15
ong		56 1245
ful		56 123
tion		56 1345
ness		56 234
ment		56 2345
ity		56 13456

Talkback Basics

Key Combo	Action
Hold z	Pause/Resume Talkback
Alt + Space	Open Talkback Menu

Item Navigation controls

Key Combo	Action
Alt + Left	Navigate to the next item
Alt + Right	Navigate to the previous item
Alt + Up	Navigate to the item above
Alt + Down	Navigate to the item below
_________	________
Alt + Ctrl + Left	Navigate to First Item
Alt + Ctrl + Right	Navigate to Last Item
Alt + Ctrl + Down	Navigate to Next Window
Alt + Ctrl + Up	Navigate to Previous Window
_________	________
Alt + Enter	Select an item
Alt + Shift + Enter	Long press

Text Editing

Key Combo	Action
Right	Move cursor right
Left	Move cursor left
Up	Move cursor to line above
Down	Move cursor to line below
Ctrl + Right	Move cursor to Previous Word
Ctrl + Left	Move Cursor to Next Word
Shift + Right	Select next character
Shift + Left	Select Previous Character
Shift + Up	Select Line Above
Shift + Down	Select Line Below
Shift + Ctrl + Left	Select Previous Word
Shift + Ctrl + Right	Select Next Word

Reading controls

Key Combo	Action
Alt + Shift + Control + Up/Down	Cycle Reading Controls
Alt + Shift + Up/Down	Go to Next/Prev as per reading Controls
Alt + Shift + Right	Navigate to Next Character
Alt + Shift + Left	Navigate to Previous Character
Alt + Ctrl + Shift + Right	Navigate to Next Word
Alt + Ctrl + Shift + Left	Navigate to Previous Word

Continuous Reading controls

Key Combo	Action
Alt + Ctrl + Enter	Continuous read from top
Alt + Ctrl + Shift + Enter	Continuous read from Next Item
Alt + Right	Fast-forwards the text.
Alt + Left	Rewinds the text.
Enter	Stop Continuous Reading

Slider Controls

Key Combo	Action
Alt + Shift + Up	Increase Slider Value
Alt + Shift + Down	Decrease Slider Value

Alphabetic Shortcuts

Long press braille character to activate

CHARACTER	Shortcut	Key Combo
a	Assistant	win
b	Back	alt + backspace
l	Apps List / Select All	Ctrl + a
c	Copy	ctrl + c
x	Cut	ctrl + x
v	Paste	ctrl + v
d	Maps	win + m
e	Email	win + e
h	Home	ctrl + alt + h
r	Recent apps	ctrl + alt + r
s	Music	win + p
m	Messages	win + s
n	notifications	ctrl + alt + n
f	Screen Search	ctrl + alt + /
p	Contacts	win + c
y	Youtube	win + y
t	Calender	win + l

References:

1. Generate Markdwn tables from https://www.tablesgenerator.com/markdown_tables
2. Braille Code Referance: https://www.pharmabraille.com/braille-codes/unified-english-braille-ueb-code/
3. Test and understand using online braille translator: https://www.branah.com/braille-translator
4. Wikipedia entry https://en.wikipedia.org/wiki/English_Braille
5. http://www.dotlessbraille.org/brailleindicators.htm#markup
6. Android & TalkBack Mobile Accessibility Cheat Sheet https://pauljadam.com/demos/talkbackcheatsheet.html
7. Keyboard Shortcuts https://www.cnet.com/culture/keyboard-shortcuts-for-android-phones/
8. Talkback Shortcuts https://dequeuniversity.com/screenreaders/talkback-shortcuts
9. Braille to Binary encoder https://www.dcode.fr/braille-alphabet

TIPO

Plug n Play Braille Keyboard for your smartphone Shows up as a HID device, and behaves just like a Keyboard would.

TIPO V1

USB HID only implementation using atmega32u4/Adruni Leonardo

TIPO BLE

BLE HID implementation using ESP32

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Hardware Connections

Architecture

Button Map:

Button	ESP32 Pin #
BTN1	25
BTN2	26
BTN3	27
BTN4	13
BTN5	15
BTN6	2
BTN7	19
BTN8	18
BTN9	17
BTN10	16
BTN11	4
CNT	33
UP	34
DWN	35
LFT	36
RGT	39