Using Sigfox and UART 1 causes instability

[noxqs]

I am suspecting the default UART 1 pins are shared wit the Sigfox pins because when I hook up a NMEA GPS module over UART 1, anything I do with an object created from the Sigfox module may hang the SiPy.
The simplest way to reproduce is to run

• sigfox = Sigfox(mode=Sigfox.SIGFOX, rcz=Sigfox.RCZ4)
• soft reboot (CTRL-D)
• sigfox = Sigfox(mode=Sigfox.SIGFOX, rcz=Sigfox.RCZ4)
• hang 100%

There is no way to reset the sigfox without creating the sigfox object ?

Anyone with this similar problem ?

[livius]

@noxqs
interesting that in pinout there are no description of UART
on the left is for Wipy2

[noxqs]

From the pinout image above and uart example url link text we lerarn the UART default pinouts:
UART0 uses RX/TX PIN0 and PIN1
UART1 uses RX/TX PIN3 and PIN4

[jmarcelino]

@noxqs
The Sigfox chip on the SiPy doesn't use UART.

Can you explain a bit better how the GPS is affecting it? If you try the steps you listed without a GPS it works? Trying to understand the relevancy.

The problem around re-instantiating the Sigfox class after soft reboot is known - see https://forum.pycom.io/topic/941/sipy-crashes-when-attempting-to-initialise-sigfox-twice - try using machine.reset() instead of Ctrl-D

[noxqs]

@jmarcelino
Yes, my problem is the same as what you highlight, thanks for solving the mystery.
As an temp solution (for lazy ppl) I can suggest :

# hard reset if last was a soft reset
if reset_cause() == 4:
    reset()
if not 'sigfox' in locals():
    sigfox = Sigfox(mode=Sigfox.SIGFOX, rcz=Sigfox.RCZ4)

Regarding the UART1 activity causing Sigfox instability, I will do more tests later.
Maybe update the SiPy pinout PDF to include the UART1 pins (like LoPy) as @livius mentioned?