Poor man's flexible input device: keyboard sketched on paper and a touchscreen

[espruino-discuss3]

Posted at 2018-10-04 by @allObjects

A hybrid of old and new technology: A resistive touch screen over a sketched / printed 'keyboard' layout provides flexible input options. Getting rid of physical buttons and have unlimited entry options - that's what this is all about.

Here is my universal Espruino (PICO) keyboard. A few modules including a configuration module make a simple calculator entry.

---

Attachments:

• calc2touchkeyPad.jpg
  
• calcToUpload.png

[espruino-discuss3]

Posted at 2018-10-04 by @allObjects

Here part of the code with input/output example:

// touchKeyPadCalc2.js
// (c)20181004_aO
var kvs = "789CA456*/123+-00.==" // key values grid linear
  , tkp = new (require("TouchKeyPad"))(
     0,141,24,103,5,4,kvs) // grid area, cols, rows
  , trd = new (require("TouchRD"))(B1,A5,A6,A7
    ,function(x,y,t) { if (!t.t) // on un-touch:
      console.log(t.x,t.y,tkp.key(t.x,t.y),tkp.k,tkp.r,tkp.c); }
    ,require("TSRD26_142x104_cfg")
    );

The actual calculator is still on the list (suggestions are welcome) as well as attaching any kind of display. Output of input shows in console so far (: - Touching 8 2 . 5 x 3 = produces this output (formatted and 'headed' posthume for legibility):

`
touched lup lin -grid-
@       key key row col
  x   y val idx idx idx
--- --- --- --- --- ---
 38  36  8    1   0   1
 39  76  2   11   2   1
 64 100  .   17   3   2
 40  58  5    6   1   1
 96  57  *    8   1   3
 69  75  3   12   2   2
108  96  =   18   3   3
`

PS: Configured screen resolution is 142 W x 104 H spots (pixels), 0/0 is at left (x) top (y). Reasons for chosen resolution will be subject of another conversation.

...more to come...

[espruino-discuss3]

Posted at 2018-10-08 by @MaBecker

Wow, I like that touch screen

https://www.smitacn.com/resistive-touch-screen-digitizer-glass-054005.html?gclid=EAIaIQobChMIpNbK4Jb33QIV1eWaCh0tWwaiEAkYAyABEgJblfD_BwE

What about this one? Is it similar to the one you use ?

[espruino-discuss3]

Posted at 2018-10-08 by @allObjects

Yes, I got mine from https://www.buydisplay.com/ - https://www.ebay.com/usr/buydisplay - directly - the shop(s) of the manufacturer EastRising Technology Co., Ltd. I guess, because the manufacturer Web site has no other indication. I buy always 2+, because they are somewhat fragile... broke my first when 'gently pushing' it into its location in 3d printed frame,... the gently was obviously not so gentle and a corner broke off... small, but of course exactly the one with the trace going around the corner opposite of the film connector, so I lost the Upper (in portrait) feed and sense line...

buydisplay is the source of (almost) all my displays, since I do not need the fruity, access easing surroundings (from adaFruit... I though admit that my first add-ons when getting started with Original Espruino board came from adafruit: display w/ resistive touchscreen (no touch screen controller), wifi CC3000 board, and possibly M6 uBlox GPS).

[gfwilliams]

Posted at 2018-10-09 by @gfwilliams

Looks great! Do you have links to your touchRD and touchKey modules?

[espruino-discuss3]

Posted at 2018-10-09 by @allObjects

Getting the modules ready.

[espruino-discuss3]

Posted at 2018-10-16 by @allObjects

Modules are now on https://www.espruino.com/modules:

• TouchRD - Resistive Touchscreen Directly connected to Espruino
  • Documentation - TouchRD - espruino.com/TouchRD
  • Code - [TouchRD - ]espruino.com/modules/TouchRD.js](https://www.espruino.com/modules/TouchRD.js)
• TouchKeyPad - Mapping touch position in grid to a key value:
  • Documentation - TouchKeyPad - espruino.com/TouchKeyPad
  • Code - [TouchKeyPadRD - espruino.com/modules/TouchKeyPad.js]
    (https://www.espruino.com/modules/TouchKeyPad.js) ]

TouchRD Documentation includes generic code for calibration for Portrait and Landscape use.

The configuration(s) as used in post #1 were created with the generic calibration code and then copied into the modules folder of the sandbox in the Espruino IDE:

// TSRD26_104x132_cfg.js (c) 20181003_allObjects
// BuyDisplay.com 2.6" Resistive Touch Screen
// Portrait configuration 104 W x 142 H
// for TouchRD.js module
exports = 
  { X: 104
  , Y: 142
  , xt: 0.1117
  , yt: 0.0854
  , xc: 0.5067
  , yc: 0.4876
  , xd: 0.00736
  , yd: 0.00553
  };

// TSRD26_142x104_cfg.js - 20181003_allObjects
// BuyDisplay.com 2.6" Resistive Touch Screen
// Landscape configuration 142 W x 104 H
// for TouchRD.js module
exports = 
  { X: 142
  , Y: 104
  , xm: 5
  , ym: 5
  , xt: 0.0822
  , yt: 0.0966
  , xc: 0.4694
  , yc: 0.4960
  , xd: 0.00534
  , yd: 0.00744
  };