UART sendbreak bug
There is a bug with the uart.sendbreak() method with V1.17 (haven't checked the latest)
The manual states the break signal lasts 13 bits. It actually is 11.
This has caused errors with external sensors that utilize the SDI-12 protocol. .The line needs to go for at least 12ms. Now, it is 9.167 ms. Even 13 bits is not long enough.
A good solution is to add a property where you can specify how many bits you can use.
SDI-12 is popular in agriculture and other industrial applications. (www.sdi-12.org)
ESP32 Uart TX-error using UART.sendbreak()
I'm using the UART-class to send messages over serial line.
Any message is terminated with the 'BREAK'-signal.
It works so far sending more then 1 char's.
But in that special case sending only 1 char terminated with the UART.sendbreak() call,
the leading char will be overwritten or destructed.
Also the call UART.wait_tx_done(100) before sending the BREAK-signal doesn't help.
Only the call: time.sleep(0.002) before UART.sendbreak() will help a bit.
Used code:
...
uart1 = UART(1, baudrate=9600)
while True:
uart1.write('A')
while uart1.wait_tx_done(100) == False:
pass
# !! sleep required for 1Char- and break-send !!
time.sleep(0.002)
uart1.sendbreak()
time.sleep(1)
Used environment:
ESP32 on Wipy3.0
See attached plots for the resulting streams.
Can you fix this problem in further releases?
