use SPI directly for 1-byte commands

Author: 2bndy5

circuitpython_nrf24l01/rf24.py

@@ -167,20 +167,13 @@ def ce_pin(self) -> bool:
     def ce_pin(self, val: bool):
         self._ce_pin.value = val
 
-    def _reg_read(self, reg: int, command: bool = False) -> int:
+    def _reg_read(self, reg: int) -> int:
         self._out[0] = reg
-        len = int(not command) + 1
         with self._spi as spi:
             # time.sleep(0.000005)
-            spi.write_readinto(self._out, self._in, out_end=len, in_end=len)
-        # if command:
-        #     if reg != 0xFF:
-        #         print("SPI command", ("%02X" % reg))
-        # else:
-        #     print(
-        #         "SPI read", len, "byte from", ("%02X" % reg), ("%02X" % self._in[1])
-        #     )
-        return self._in[not command]
+            spi.write_readinto(self._out, self._in, out_end=2, in_end=2)
+        # print("SPI read", len, "byte from", ("%02X" % reg), ("%02X" % self._in[1]))
+        return self._in[1]
 
     def _reg_read_bytes(self, reg: int, buf_len: int = 5) -> bytearray:
         self._out[0] = reg
@@ -379,7 +372,9 @@ def irq_df(self) -> bool:
 
     def update(self) -> Literal[True]:
         """This function gets an updated status byte over SPI."""
-        self._reg_read(0xFF, command=True)
+        self._out[0] = 0xFF
+        with self._spi as spi:
+            spi.write_readinto(self._out, self._in, in_end=1, out_end=1)
         return True
 
     def clear_status_flags(
@@ -807,7 +802,9 @@ def resend(self, send_only: bool = False):
         if not send_only and (self._in[0] >> 1) < 6:
             self.flush_rx()
         self.clear_status_flags()
-        # self._reg_read(0xE3, command=True)
+        # self._out = 0xE3  # REUSE_TX command
+        # with self._spi as spi:
+        #     spi.write_readinto(self._out, self._in, in_end=1, out_end=1)
         up_cnt = 0
         self._ce_pin.value = True
         while not self._in[0] & 0x30:
@@ -846,11 +843,15 @@ def write(
 
     def flush_rx(self):
         """Flush all 3 levels of the RX FIFO."""
-        self._reg_read(0xE2, command=True)
+        self._out = 0xE2
+        with self._spi as spi:
+            spi.write_readinto(self._out, self._in, in_end=1, out_end=1)
 
     def flush_tx(self):
         """Flush all 3 levels of the TX FIFO."""
-        self._reg_read(0xE1, command=True)
+        self._out = 0xE1
+        with self._spi as spi:
+            spi.write_readinto(self._out, self._in, in_end=1, out_end=1)
 
     def fifo(self, about_tx: bool = False, check_empty: Optional[bool] = None):
         """This provides the status of the TX/RX FIFO buffers. (read-only)"""