Revert "listen won't flush RX FIFO; flush TX FIFO of ACKs"

This reverts commit 6e8eb83.

circuitpython_nrf24l01/rf24.py

@@ -245,12 +245,11 @@ def listen(self, is_rx):
                 self._config = (self._config & 0xFC) | 3
                 self._reg_write(CONFIGURE, self._config)
                 time.sleep(0.00015)  # mandatory wait to power up radio
+                self.flush_rx()
                 self.clear_status_flags()
                 self.ce_pin.value = 1  # mandatory pulse is > 130 µs
                 time.sleep(0.00013)
             else:
-                if self.ack:
-                    self.flush_tx()
                 self._config = self._config & 0xFE
                 self._reg_write(CONFIGURE, self._config)
                 time.sleep(0.00016)

docs/basic_api.rst

@@ -84,13 +84,13 @@ listen
         - `True` enables RX mode. Additionally, per `Appendix B of the nRF24L01+ Specifications
           Sheet <https://www.sparkfun.com/datasheets/Components/SMD/
           nRF24L01Pluss_Preliminary_Product_Specification_v1_0.pdf#G1091756>`_, this attribute
-          clears the `irq_dr` status flag and puts nRF24L01 in power up
+          flushes the RX FIFO, clears the `irq_dr` status flag, and puts nRF24L01 in power up
           mode. Notice the CE pin is be held HIGH during RX mode.
         - `False` disables RX mode. As mentioned in above link, this puts nRF24L01's power in
           Standby-I (CE pin is LOW meaning low current & no transmissions) mode which is ideal
-          for post-reception work. Disabing RX mode will only flush the TX FIFO buffers if the
-          `ack` attribute is enabled. Remember to manage your 3-level RX FIFO buffers using the
-          `flush_rx()` or `recv()` functions.
+          for post-reception work. Disabing RX mode doesn't flush the RX/TX FIFO buffers, so
+          remember to flush your 3-level FIFO buffers when appropriate using `flush_tx()` or
+          `flush_rx()` (see also the `recv()` function).
 
 any()
 ******************

examples/nrf24l01_ack_payload_test.py

@@ -48,7 +48,8 @@
 def master(count=5):  # count = 5 will only transmit 5 packets
     """Transmits a payload every second and prints the ACK payload"""
     nrf.listen = False  # put radio in TX mode
-    nrf.open_tx_pipe(address)  # set address of RX node into a TX pipe
+    # set address of RX node into a TX pipe
+    nrf.open_tx_pipe(address)
 
     while count:
         buffer = b"Hello " + bytes([count + 48])  # output buffer
@@ -73,7 +74,8 @@ def slave(count=5):
     # set address of TX node into an RX pipe. NOTE you MUST specify
     # which pipe number to use for RX; we'll be using pipe 0
     nrf.open_rx_pipe(0, address)
-    nrf.listen = True  # put radio into RX mode, power it up
+    # put radio into RX mode, power it up
+    nrf.listen = True
 
     # setup the first transmission's ACK payload
     buffer = ACK + bytes([count + 48])
@@ -94,7 +96,8 @@ def slave(count=5):
                 nrf.load_ack(buffer, 0)  # load ACK for next response
 
     # recommended behavior is to keep in TX mode while idle
-    nrf.listen = False  # put radio in TX mode & flush unused ACK payloads
+    nrf.listen = False  # put radio in TX mode
+    nrf.flush_tx()  # flush any ACK payloads that remain
 
 
 print(

examples/nrf24l01_interrupt_test.py

@@ -125,11 +125,12 @@ def slave(timeout=6):  # will listen for 6 seconds before timing out
     while not nrf.fifo(0, 0) and time.monotonic() - start_timer < timeout:
         # if RX FIFO is not full and timeout is not reached, then keep going
         pass
-    nrf.listen = False  # put nRF24L01 in TX mode & discard any ACK payloads
-    if self.pipe is not None:  # if RX FIFO is not empty
+    nrf.listen = False  # put nRF24L01 in Standby-I mode when idling
+    if not nrf.fifo(False, True):  # if RX FIFO is not empty
         # all 3 payloads received were 5 bytes each, and RX FIFO is full
         # so, fetching 15 bytes from the RX FIFO also flushes RX FIFO
         print("Complete RX FIFO:", nrf.recv(15))
+    nrf.flush_tx()  # discard any pending ACK payloads
 
 
 print(

examples/nrf24l01_multiceiver_test.py

@@ -60,9 +60,7 @@ def base(timeout=10):
             start_timer = time.monotonic()  # reset timer with every payload
             if nrf.load_ack(ACK, 1):  # keep TX FIFO full with ACK payloads
                 print("\t ACK re-loaded")
-    # recommended behavior is to keep in TX mode while idle
-    nrf.listen = False  # put radio in TX mode & flush unused ACK payloads
-
+    nrf.listen = False
 
 
 def node(node_number, count=6):