diff options
Diffstat (limited to 'drivers/nrf24l01/nrf24l01.py')
| -rw-r--r-- | drivers/nrf24l01/nrf24l01.py | 96 |
1 files changed, 56 insertions, 40 deletions
diff --git a/drivers/nrf24l01/nrf24l01.py b/drivers/nrf24l01/nrf24l01.py index 255aade83f..2db3546814 100644 --- a/drivers/nrf24l01/nrf24l01.py +++ b/drivers/nrf24l01/nrf24l01.py @@ -1,4 +1,11 @@ -"""NRF24L01 driver for Micro Python""" +"""NRF24L01 driver for Micro Python + +Support for nonblocking send added. Minor fixes: +Timeout now uses pyb.elapsed_millis(). +Channel numbers constrained to 125 as per datasheet. +Status register read with reg_read() - reg_read_ret_status() removed. +Default speed 250K for improved range/error rate. +""" import pyb @@ -69,8 +76,10 @@ class NRF24L01: self.pipe0_read_addr = None pyb.delay(5) - # set address width to 5 bytes + # set address width to 5 bytes and check for device present self.reg_write(SETUP_AW, 0b11) + if self.reg_read(SETUP_AW) != 0b11: + raise OSError("nRF24l01+ Hardware not responding") # disable dynamic payloads self.reg_write(DYNPD, 0) @@ -80,7 +89,7 @@ class NRF24L01: self.reg_write(SETUP_RETR, (6 << 4) | 8) # set rf power and speed - self.set_power_speed(POWER_3, SPEED_1M) + self.set_power_speed(POWER_3, SPEED_250K) # Best for point to point links # init CRC self.set_crc(2) @@ -102,13 +111,6 @@ class NRF24L01: self.cs.high() return buf[0] - def reg_read_ret_status(self, reg): - self.cs.low() - status = self.spi.send_recv(reg)[0] - buf = self.spi.recv(1) - self.cs.high() - return status - def reg_write(self, reg, buf): self.cs.low() status = self.spi.send_recv(0x20 | reg)[0] @@ -143,7 +145,7 @@ class NRF24L01: self.reg_write(CONFIG, config) def set_channel(self, channel): - self.reg_write(RF_CH, min(channel, 127)) + self.reg_write(RF_CH, min(channel, 125)) # Changed from 127 # address should be a bytes object 5 bytes long def open_tx_pipe(self, address): @@ -194,41 +196,55 @@ class NRF24L01: self.spi.send(R_RX_PAYLOAD) buf = self.spi.recv(self.payload_size) self.cs.high() - # clear RX ready flag self.reg_write(STATUS, RX_DR) return buf - def send(self, buf, timeout=500): - # power up - self.reg_write(CONFIG, (self.reg_read(CONFIG) | PWR_UP) & ~PRIM_RX) - pyb.udelay(150) - - # send the data - self.cs.low() - self.spi.send(W_TX_PAYLOAD) - self.spi.send(buf) - if len(buf) < self.payload_size: - self.spi.send(b'\x00' * (self.payload_size - len(buf))) # pad out data - self.cs.high() - - # enable the chip so it can send the data - self.ce.high() - pyb.udelay(15) # needs to be >10us - self.ce.low() - # blocking wait for tx complete + def send(self, buf, timeout=500): + send_nonblock = self.send_nonblocking(buf) start = pyb.millis() - while pyb.millis() - start < timeout: - status = self.reg_read_ret_status(OBSERVE_TX) - if status & (TX_DS | MAX_RT): - break - - # get and clear all status flags - status = self.reg_write(STATUS, RX_DR | TX_DS | MAX_RT) - if not (status & TX_DS): + result = None + while result is None and (pyb.elapsed_millis(start) < timeout): + result = send_nonblock() # 1 == success 2 == fail + if result == 2: raise OSError("send failed") - # power down - self.reg_write(CONFIG, self.reg_read(CONFIG) & ~PWR_UP) + def send_nonblocking(self, buf): + ''' + Support for nonblocking transmission. Returns a function instance. + The first call to a function instance sends the data and returns None. + Subsequent calls test TX status returning not ready None, ready 1, error 2. + ''' + init = True + def make_snb(): + nonlocal init + if init: + # power up + self.reg_write(CONFIG, (self.reg_read(CONFIG) | PWR_UP) & ~PRIM_RX) + pyb.udelay(150) + + # send the data + self.cs.low() + self.spi.send(W_TX_PAYLOAD) + self.spi.send(buf) + if len(buf) < self.payload_size: + self.spi.send(b'\x00' * (self.payload_size - len(buf))) # pad out data + self.cs.high() + + # enable the chip so it can send the data + self.ce.high() + pyb.udelay(15) # needs to be >10us + self.ce.low() + init = False + return None # Not ready + + if not (self.reg_read(STATUS) & (TX_DS | MAX_RT)): + return None # Not ready + # Either ready or failed: get and clear status flags, power down + status = self.reg_write(STATUS, RX_DR | TX_DS | MAX_RT) + self.reg_write(CONFIG, self.reg_read(CONFIG) & ~PWR_UP) + return 1 if status & TX_DS else 2 + return make_snb + |