FiPy or Gpy as modem?

[jmarcelino]

@electronic
I’ve never tested with a Raspberry Pi but you should be able to connect the FiPy pins as listed LTE_RX, LTE_TX, LTE_CTS, LTE_RTS to the corresponding UART pins + GND on the Raspberry Pi

https://docs.pycom.io/chapter/datasheets/downloads/fipy-pinout.pdf

You should also hold the FiPy I reset by holding th line to GND.

UART speed is 921600 with CTS/RTS hardware flow control

On the GPy the pins aren’t exposed, you can only do it (directly at least, without fiddling with the software) on the FiPy

[soulsurfer]

@jmarcelino This is intriguing news! Has this ever been tested using something other than a Raspberry Pi?

I have several old Pis and I could try the obvious experiment. However I've only just received my very first FiPy and I'm reluctant to risk damaging it before even using it anger for the first time.

[jmarcelino]

@soulsurfer
Yes this works on Mac and Windows using a USB-serial adapter, it's the setup used for certification.

[Sebastien]

@jmarcelino
Hi, Has anybody tested this configuration successfully ?
(I mean with Raspberry Pi Serial <==> LTE_RX, TX, CTS, RTS))
when you mention : "reset by holding the line to GND." , you ment pin1 (RST) connected to the GND ?
Thanks in advance

[robert-hh]

@sebastien Yes, the RST pin, next to the Reset button. Pulling that low keeps the ESP32 in reset state and all it's GPIO's floating.
(P.S.: That's a trick used also by Arduino people for using it as an USB/UART bride).

[Sebastien]

@robert-hh
Thanks Robert. I have done it. but still the LTE modem remain silent.

[robert-hh]

@sebastien Did you try to swap RX/TX? Or with the RTS/DTR lines?

[Sebastien]

@robert-hh
Actually, I am quite confident in the "wirering", since I can receive, on the rpi, a "+sysstart" message when the I leave Fipy starting by itself ... I meant silent because I do not have any "OK / ERROR" message after the simple commands like AT, ATE1 or ATZ ... I try to communicate between Fipy & Rpi via "minicom -b 921600 -o -D /dev/serial0 ctsrts" (on the rpi , the serial0 is ttyAMA0 , and the CTS RTS pins are also enabled)

[Sebastien]

@sebastien
Ah ah ! I found my mistake :-) it works now when i initialize my serial port as follow :
stty -F /dev/ttyAMA0 921600 raw -echo -echoe -echok -crtscts
Thanks !

[bitvijays]

Hey @Sebastien, Hope you are doing well. Just curious, were you able to use FiPy/ GPy as a modem? If so, how? If we connect UART of Pi with LTE RX, TX. does it act like a network interface like lte0? eth0?

Also, if we are able to do this, by default the way of communication (accessing internet) would be via LTE? What if, we want to use SigFox or Wifi?

Also, is there a detail blog post regarding the same?

Cheers,
Vijay