Hand-wiring a keyboard

1. Hand-wire the keyboard

2. Follow the guide - How to Program Pitaya Go to flash CircuitPython firmware

3. Download two CircuitPython libraries - adafruit-ble & adafruit-hid and put them into the lib directory of the USB drive named CIRCUITPY.

   CIRCUITPY
   ├───code.py
   └───lib
       ├───adafruit_ble
       └───adafruit_hid

4. Copy the Python code to code.py. When code.py is reloaded, you will get a keyboard with USB & Bluetooth

   import time
   from board import *
   import digitalio
   import usb_hid
   
   import adafruit_ble
   from adafruit_ble.advertising import Advertisement
   from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
   from adafruit_ble.services.standard.hid import HIDService
   from adafruit_hid.keyboard import Keyboard
   from adafruit_hid.keycode import Keycode as _
   
   ROWS = (P27, P13, P30, P20, P3)
   COLS = (P26, P31, P29, P28, P5, P4, P24, P25, P23, P22, P14, P15, P16, P17)
   
   KEYMAP = (_.ESCAPE, _.ONE, _.TWO, _.THREE, _.FOUR, _.FIVE, _.SIX, _.SEVEN, _.EIGHT, _.NINE, _.ZERO, _.MINUS, _.EQUALS, _.BACKSPACE,
           _.TAB, _.Q, _.W, _.E, _.R, _.T, _.Y, _.U, _.I, _.O, _.P, _.LEFT_BRACKET, _.RIGHT_BRACKET, _.BACKSLASH,
           _.CAPS_LOCK, _.A, _.S, _.D, _.F, _.G, _.H, _.J, _.K, _.L, _.SEMICOLON, _.QUOTE, None, _.ENTER,
           _.LEFT_SHIFT, _.Z, _.X, _.C, _.V, _.B, _.N, _.M, _.COMMA, _.PERIOD, _.FORWARD_SLASH, None, _.RIGHT_SHIFT, None,
           _.LEFT_CONTROL, _.LEFT_ALT, _.LEFT_GUI, None, None, _.SPACE, None, None, _.RIGHT_ALT, _.RIGHT_GUI, _.APPLICATION, _.RIGHT_CONTROL, None, None)
   
   class Matrix:
       def __init__(self, rows=ROWS, cols=COLS):
           self.rows = []
           for pin in rows:
               io = digitalio.DigitalInOut(pin)
               io.direction = digitalio.Direction.OUTPUT
               io.drive_mode = digitalio.DriveMode.PUSH_PULL
               io.value = 0
               self.rows.append(io)
           self.cols = []
           for pin in cols:
               io = digitalio.DigitalInOut(pin)
               io.direction = digitalio.Direction.INPUT
               io.pull = digitalio.Pull.DOWN
               self.cols.append(io)
           self.pressed_keys = []
   
       def scan(self):
           new_keys = []
           pressed_keys = []
           released_keys = self.pressed_keys
           for r in range(len(self.rows)):
               self.rows[r].value = 1
               for c in range(len(self.cols)):
                   if self.cols[c].value:
                       key = r * len(self.cols) + c
                       pressed_keys.append(key)
                       if key in released_keys:
                           released_keys.remove(key)
                       else:
                           new_keys.append(key)
               self.rows[r].value = 0
           self.pressed_keys = pressed_keys
           return pressed_keys, released_keys, new_keys
   
   def main():
       hid = HIDService()
       advertisement = ProvideServicesAdvertisement(hid)
       advertisement.appearance = 961
       ble = adafruit_ble.BLERadio()
       if ble.connected:
           for c in ble.connections:
               c.disconnect()
       ble.start_advertising(advertisement)
       advertising = True
       ble_keyboard = Keyboard(hid.devices)
   
       matrix = Matrix()
       usb_keyboard = Keyboard(usb_hid.devices)
   
       while True:
           pressed_keys, released_keys, new_keys = matrix.scan()
           if released_keys:
               released_keycodes = list(map(lambda i: KEYMAP[i], released_keys))
               print('released keys {}'.format(released_keycodes))
   
               usb_keyboard.release(*released_keycodes)
               if ble.connected:
                   advertising = False
                   ble_keyboard.release(*released_keycodes)
           if new_keys:
               new_keycodes = list(map(lambda i: KEYMAP[i], new_keys))
               print('new keys {}'.format(new_keycodes))
               usb_keyboard.press(*new_keycodes)
               if ble.connected:
                   advertising = False
                   ble_keyboard.press(*new_keycodes)
   
           if not ble.connected and not advertising:
               ble.start_advertising(advertisement)
               advertising = True
   
           time.sleep(0.001)
   
   if __name__ == '__main__':
       main()

   If you have a different configuration of raws and columns, you must change ROWS and COLS in the code.