Read all 4 buttons with one call.

Fixes #10 - uses the same `digital_read_bulk` Seesaw method, but
returns all of the button states as list. This improves read
performance since each individual button does not need to be read.

Author: EAGrahamJr

adafruit_neokey/neokey1x4.py

@@ -71,3 +71,16 @@ def __getitem__(self, index: int) -> bool:
         if not isinstance(index, int) or (index < 0) or (index > 3):
             raise RuntimeError("Index must be 0 thru 3")
         return not self.digital_read(index + 4)
+
+    def get_keys(self) -> typing.List[bool]:
+        """Read all 4 keys at once and return an array of booleans.
+
+        Returns:
+            typing.List[bool]: _description_
+        """
+        # use a bit mask with ports 4-7 to read all 4 keys at once
+        bulk_read = self.digital_read_bulk(0xF0)
+
+        # convert the leftmost 4 bits to an array of booleans and return
+        keys = [bulk_read & (1 << i) == 0 for i in range(4, 8)]
+        return keys

examples/neokey1x4_allkeys.py

@@ -0,0 +1,51 @@
+# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
+# SPDX-License-Identifier: MIT
+"""NeoKey simpletest."""
+import board
+from adafruit_neokey.neokey1x4 import NeoKey1x4
+from time import sleep
+
+# use default I2C bus
+i2c_bus = board.I2C()
+
+# Create a NeoKey object
+neokey = NeoKey1x4(i2c_bus, addr=0x30)
+
+print("Adafruit NeoKey simple test reading all keys")
+
+# neokey.edbug = True
+
+while True:
+    keys = neokey.get_keys()
+    print(f"keys {keys}")
+    # test for all buttons pressed at once
+    if keys[0] and keys[1] and keys[2] and keys[3]:
+        for i in range(4):
+            neokey.pixels[i] = 0xFF00FF
+    # check each key individually
+    else:
+        if keys[0]:
+            print("Button A")
+            neokey.pixels[0] = 0xFF0000
+        else:
+            neokey.pixels[0] = 0x0
+
+        if keys[1]:
+            print("Button B")
+            neokey.pixels[1] = 0xFFFF00
+        else:
+            neokey.pixels[1] = 0x0
+
+        if keys[2]:
+            print("Button C")
+            neokey.pixels[2] = 0x00FF00
+        else:
+            neokey.pixels[2] = 0x0
+
+        if keys[3]:
+            print("Button D")
+            neokey.pixels[3] = 0x00FFFF
+        else:
+            neokey.pixels[3] = 0x0
+
+    sleep(2)