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improve scanner promiscuity
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similar to changes in nRF24/RF24#955
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2bndy5 committed Jun 28, 2024
1 parent bc0147e commit c3ce23c
Showing 1 changed file with 36 additions and 16 deletions.
52 changes: 36 additions & 16 deletions examples/nrf24l01_scanner_test.py
Original file line number Diff line number Diff line change
Expand Up @@ -40,16 +40,20 @@
# 21 = bus 2, CE1 # enable SPI bus 1 prior to running this

# turn off RX features specific to the nRF24L01 module
nrf.auto_ack = False
nrf.dynamic_payloads = False
nrf.auto_ack = False
nrf.crc = 0
nrf.arc = 0
nrf.allow_ask_no_ack = False

# use reverse engineering tactics for a better "snapshot"
nrf.address_length = 2
nrf.open_rx_pipe(1, b"\0\x55")
nrf.open_rx_pipe(0, b"\0\xaa")
nrf.open_rx_pipe(0, b"\xaa\xaa")
nrf.open_rx_pipe(1, b"\x55\x55")
nrf.open_rx_pipe(2, b"\0\xaa")
nrf.open_rx_pipe(3, b"\0\x55")
nrf.open_rx_pipe(4, b"\xa0\xaa")
nrf.open_rx_pipe(5, b"\x50\x55")


def scan(timeout=30):
Expand All @@ -67,32 +71,49 @@ def scan(timeout=30):
print(str(i % 10), sep="", end="")
print("\n" + "~" * 126)

sweeps = 0
signals = [0] * 126 # store the signal count for each channel
curr_channel = 0
start_timer = time.monotonic() # start the timer
while time.monotonic() - start_timer < timeout:
nrf.channel = curr_channel
if nrf.available():
nrf.flush_rx() # flush the RX FIFO because it asserts the RPD flag
nrf.listen = 1 # start a RX session
# nrf.flush_rx()
nrf.listen = True # start a RX session
time.sleep(0.00013) # wait 130 microseconds
signals[curr_channel] += nrf.rpd # if interference is present
nrf.listen = 0 # end the RX session
curr_channel = curr_channel + 1 if curr_channel < 125 else 0
found_signal = nrf.rpd
nrf.listen = False # end the RX session
found_signal = found_signal or nrf.rpd or nrf.available()

# count signal as interference
signals[curr_channel] += found_signal
# clear the RX FIFO if a signal was detected/captured
if found_signal:
nrf.flush_rx() # flush the RX FIFO because it asserts the RPD flag
endl = False
if curr_channel > 124:
sweeps += 1
if sweeps >= 15:
endl = True
sweeps = 0

# output the signal counts per channel
sig_cnt = signals[curr_channel]
print(
("%X" % min(15, sig_cnt)) if sig_cnt else "-",
("%X" % sig_cnt) if sig_cnt else "-",
sep="",
end="" if curr_channel < 125 else "\r",
end="" if curr_channel < 125 else ("\n" if endl else "\r"),
)
curr_channel = curr_channel + 1 if curr_channel < 125 else 0
if endl:
signals = [0] * 126

# finish printing results and end with a new line
while curr_channel < len(signals) - 1:
curr_channel += 1
sig_cnt = signals[curr_channel]
print(("%X" % min(15, sig_cnt)) if sig_cnt else "-", sep="", end="")
print(("%X" % sig_cnt) if sig_cnt else "-", sep="", end="")
print("")
nrf.flush_rx() # flush the RX FIFO for continued operation


def noise(timeout=1, channel=None):
Expand All @@ -107,13 +128,12 @@ def noise(timeout=1, channel=None):
nrf.listen = True
timeout += time.monotonic()
while time.monotonic() < timeout:
signal = nrf.read()
if signal:
print(address_repr(signal, False, " "))
if nrf.available():
print(address_repr(nrf.read(32), False, " "))
nrf.listen = False
while not nrf.fifo(False, True):
# dump the left overs in the RX FIFO
print(address_repr(nrf.read(), False, " "))
print(address_repr(nrf.read(32), False, " "))


def set_role():
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