Gpy readiness

[jmarcelino]

@sam
Sequans has not enabled all the bands in the LTE modem firmware, these will come later (I don't have a date yet)

We are working on arbitrary AT commands from MicroPython. Currently you can add them at the C level / custom firmware as a I suggested in my previous answer. Another way to access the modem (only on the FiPy) is through the LTE_RX, TX, CTS, RTS pins (3.3V levels). You can hold the ESP32 in reset while doing so. Serial rate is 921600bps 8N1 CTS/RTS flow control

[Redferne]

@jmarcelino

I confirmed with our internal network support that the LTE M.1 is on Band 3 and EARFCN 1925. Tried shooting the "addscanfreq..." command and it is accepted but no dice. Modem refuses to register and a AT+COPS=? comes up empty.

AT COMMAND: [AT!="addscanfreq band=3 dl-earfcn=1925"..]AT RESPONSE: [....OK..]
AT COMMAND: [AT+CPIN?..]AT RESPONSE: [..+CPIN: READY....OK..]
AT COMMAND: [AT+CFUN=1.]AT RESPONSE: [..OK..]
AT COMMAND: [AT+COPS=?..]AT RESPONSE: [..+COPS: ,,(0,1,2,3,4),(0,1,2)....OK..]
AT COMMAND: [AT+CEREG?..]AT BAD RESPONSE: [..+CEREG: 2,4....OK..]
C, restarting...
AT COMMAND: [AT+CEREG?..]AT BAD RESPONSE: [..+CEREG: 2,4....OK..]
C, restarting...
AT COMMAND: [AT+CEREG?..]AT BAD RESPONSE: [..+CEREG: 2,4....OK..]
C, restarting...
AT COMMAND: [AT+CEREG?..]AT BAD RESPONSE: [..+CEREG: 2,4....OK..]
C, restarting...
AT COMMAND: [AT+CEREG?..]AT BAD RESPONSE: [..+CEREG: 2,4....OK..]
...

[jmarcelino]

@redferne

Thanks so much for your tests, that looks quite conclusive.
I'll relay it to Sequans for their advice.

[Sam]

@jmarcelino
has these devices been ever tested? looks like we are the guinea pigs testing these for first time on certain bands :(
we find it hard to believe if these were lab tested with correct bands they fail so miserably on live networks.

[kevin]

@jmarcelino
We are also testing modules against our own lab network (NB-IoT in this case) and have had success interoperating with a number of other manufacturers by using their AT command interfaces directly.
We now have the Gpy, but no real way to test it. A basic AT command interface (e.g., via MicroPython as mentioned in another post) would be very useful - when do you expect to have this available? Can you point us to the full AT command reference from Sequans?
Also, we require B8 operation. I did not see this in your list of currently supported bands; what is the reason for this restriction? When will it be supported?

[Electrozest]

@jmarcelino
On the GPy which ESP32 GPIO pins are used for the LTE modem? The LTE_Tx pin is not shown the pinout.
Also should all NBIoT functionality be available from the AT command interface once the LTE modem has new firmware?
Thanks.

[jmarcelino]

Hi @electrozest
You can find GPIO numbers as described in the GPy board configuration:

https://github.com/pycom/pycom-micropython-sigfox/blob/master/esp32/boards/GPY/mpconfigboard.h

#define CONFIG_GSM_TX 5
#define CONFIG_GSM_RX 23
#define CONFIG_GSM_CTS 18
#define CONFIG_GSM_RTS 19

This is relative to the ESP32, so TX is TX from the ESP32 or RX from the modem side, same applies to RX, CTS and RTS.

[kevin]

@jmarcelino
Can you also relay this result to Sequans? We ran a similar test with modified Gpy FW on our Band 8 NB1 lab network. Note the response to "AT+COPS=?" appears to show support only for AT&T, and the CEREG result code is 0 (meaning it is not searching for an operator - maybe due to lack of B8 support?).

[jmarcelino]

@kevin
That's to be expected, you'll need a completely different LTE modem firmware for NB-IoT as well as band 8 support.

[kevin]

@jmarcelino
Thanks. When should we expect that to be available?

[jmarcelino]

@kevin
NB-IoT will be later next month. We're trying to have a test firmware to support all 12 bands as well, but due to lack of certification and calibration procedures that will be for testing only.

[brotherdust]

@jmarcelino I tried your method using my expansion board. I know CTS/RTS is working because it's handshaking correctly. When I take my FiPy off of reset, I can see the AT commands coming from the ESP32. However, it's not responding to anything I type into the terminal. Any thoughts on what could be happening here? Thanks!!

[jmarcelino]

Hi @brotherdust

I think your TX and RX are swapped if you want to communicate with the modem.

Also explains why you see the ESP32 - in this case you want to emulate it so you should not see it.

Please try swapping th RX/TX and keep the ESP32 in reset.

[brotherdust]

@jmarcelino
/me face-palms
There. are. no. words.

Thank you.

[Redferne]

Is there anyway to get to the LTE TX & RTS pin on the GPy?
Are they available on the pads on bottom side of the PCB?
I'm really tired of recompiling each time I think I have some magic AT command to get the Sequans modem to play ball...

[brotherdust]

@redferne Aren't the pins documented? Looks like it to me. If I had a GPy, I would use my expansion board similar to how I did it with the FiPy; just with different pin locations. =)

[brotherdust]

@brotherdust said in Gpy readiness:

@redferne Aren't the pins documented? Looks like it to me. If I had a GPy, I would use my expansion board similar to how I did it with the FiPy; just with different pin locations. =)

Ah, I see now what you are saying. That's a bummer they didn't break it out on any pins. Looks like you'll have to play whack-a-mole for a bit to find those pads!

[Redferne]

Yeah. On the GPy there's a bunch of pogo pads underneath. I might just start testing them one by one... ;-]

[jmarcelino]

Sorry to say but those UART pins are not mapped onto test points or external pins on the GPy. They only connect to the ESP32.

[Filip]

This post is deleted!