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Concertina Bauplan/en

Version vom 29. September 2019, 20:41 Uhr von Johannes (Diskussion | Beiträge) (Einbau: translation)

Concertina Construction plan

The structure of Oskar Concertina essentially consists of a microcontroller (ESP32) and 8 keys. The replica is beginner friendly. You only have to solder (leaded) components with through-hole plating. You can have the board made by a board manufacturer. The 3D printing of the case, with 0.4 mm nozzle diameter of a Kossel 3D printer, takes about 4 hours with activated support structures. The assembly takes about 1 hour. The material costs amount to approx. € 50.

Concertina

Preparation

To build Oskar Concertina you need material, tools and software.

Material: Enclosure, LiPo battery, magnets, metal plates, screws, threaded inserts, on/off switch, LiPo battery plug, LolinD32, circuit board, buttons, resistor, pin headers
  • tools tools list
    • 3D printer
    • Soldering iron and optional third hand with magnifying glass
    • side cutter
    • flat screwdriver 4.5 to 5 mm wide
    • Hexagon socket wrench 2 mm
    • Carpet knife and metal file
Werkzeug: Screwdriver, hexagon socket wrench, soldering tin, side cutter, soldering iron, optional soldering grease and third hand with magnifier

Electronics soldering

  1. First solder only the components above the microcontroller board Wemos LolinD32. Solder the resistor and only the 4 keys above the LolinD32. Attention! The solder joints of these components are then covered by the LolinD32 and can no longer be soldered after soldering the LolinD32! The 4 keys next to the LolinD32 must not be soldered to leave space for soldering the LolinD32!
board top, 4 keys and resistor are soldered in front of the LolinD32
  1. Now you can solder on LolinD32. The pin headers come between the PCB and the LolinD32 with the long pins pointing down towards the LolinD32. Solder the LolinD32 pins BAT, 13, 12, 14, 27, 26, 25, 33, 32 as well as the two GND and their adjacent pins.
    2 Pin connectors are shortened with the side cutter
  2. Then solder the remaining components (LiPo plug, on/off switch and 4 keys), and you can switch from the soldering station to the computer.
    Board underside with LolinD32, LiPo plug and on/off switch
    board top with 8 keys

Flash firmware

If you haven't installed the "Espressif IoT Development Framework" yet, follow the installation instructions of Espressif.

Download the source code of the Oskar ESP32 Firmware! There you will find a download button or the necessary git commands. Establish the USB cable connection between your computer and Oskar Concertina!

Change to the downloaded (and if necessary unpacked) directory and flash the Oskar Concertina ESP32 firmware to the microcontroller with the command "make flash". Test with "make monitor" if all keys deliver signals. Each release of a key is displayed as a bit of one byte on the monitor!

Establish a Bluetooth connection with your smartphone (or other Bluetooth enabled device that accepts Bluetooth HID keyboards)! Oskar Concertina can only pair with a new device for a limited time (30 seconds) after switching on. If it doesn't work immediately, disconnect Oskar Concertina from the power supply (via USB cable or LiPo battery) and repeat the pairing process within 30 seconds. The connection to the LiPo battery is established via the on/off switch (switch on the inner position) or interrupted (switch on the outer position).

Installation

Deburr the fresh 3D print if necessary! The screws and magnets must fit easily through the holes provided. I can recommend a carpet knife and a metal file.

Screw the threaded inserts into the holes provided in the cover.

Cover with threaded inserts

Positioniere die Platine auf dem Deckel!

Position the board on the lid! Place the LiPo battery protection on the key soldering points next to the LolinD32 and connect the LiPo battery to the PCB! Screw the magnets onto the two long screw sockets!

Screwing the magnets onto the two long screw sockets is a bit of a game of skill, because the strong magnets make unforeseen movements when screwing.

Cover with platine, LiPo battery, LiPo protection and magnets

Position the base plate and make sure that the LiPo battery lies on the LiPo battery protector and that you do not pinch the cable of the LiPo battery! Then you can tighten the base plate.

Do not overtighten the screws.

Oskar Concertina Rear and Hex Key
Oskar Concertina and hexagon socket wrench

Anwendung

Damit du Oskar Concertina schnell auf der Smartphonerückseite befestigen und wieder lösen kannst, lege zwei dünne Metallplatten an die Stelle der Magneten zwischen Smartphonehülle und Smartphone. Leicht geht das, wenn du Oskar Concertina mit den Magneten nach oben und die Smartphonehülle darauf legst. Wenn du jetzt die Metallplatten in die Smartphonehülle legst, werden sie ihren Platz magnetisch finden.

Oskar Concertina am Smartphone

Aber nicht nur am Smartphonerücken ist die kleine Tastatur nützlich, auch als Fernbedienung für Smartphone, Computer oder TV bietet Oskar Concertina interessante Möglichkeiten. LiPo-Akku lässt sich über USB-Kabel laden, wenn der Ein/Aus-Schalter "Ein" ist (Schalter auf der inneren Position).

Braille Basissystem der deutschen Blindenschrift

Wenn du die Blindenschrift Braille noch nicht beherrschst, ist jetzt die beste Gelegenheit Braille zu lernen. Wenn du keine Lust auf Braille hast, kannst du auch selber ein Tastaturlayout für die 8 Tasten entwerfen. Dazu änderst du die Einträge in der Tabelle "chord_id_keycode" in oskar_esp32/main/main.c. Oder du entwickelst einen über Umschalttasten erreichbaren Modus nach den Vorlagen Pfeil- oder WASD-Modus (arrow_modus, wasd_modus).

Viel Vergnügen beim Drücken der Knöpfe.

Weiterführende Links