nrf24l01: Increase startup delay.

marcsello · dpgeorge · commit 3e859d2118c4 · 2025-04-10T22:25:40.000+10:00
According to the datasheet of the NRF240L1 chip, 150 μs startup time is
only acceptable when the chip is clocked externally.  Most modules use a
crystal, which require 1.5 ms to settle.  It should be okay to wait more in
both cases, for a reliable startup.

Signed-off-by: Marcell Pünkösd &lt;punkosdmarcell@rocketmail.com&gt;
diff --git a/micropython/drivers/radio/nrf24l01/nrf24l01.py b/micropython/drivers/radio/nrf24l01/nrf24l01.py
@@ -227,7 +227,7 @@ def send(self, buf, timeout=500):
     def send_start(self, buf):
         # power up
         self.reg_write(CONFIG, (self.reg_read(CONFIG) | PWR_UP) & ~PRIM_RX)
-        utime.sleep_us(150)
+        utime.sleep_us(1500)  # needs to be 1.5ms
         # send the data
         self.cs(0)
         self.spi.readinto(self.buf, W_TX_PAYLOAD)
