Is it possible to send AT command from a Nucleo-L0x to a B-L072Z board? (LoRa)

[maxence forget]

Posted on May 26, 2017 at 10:47

Hi,

My purpose is to realise a new set up for LoRa.

Before, I used a B-L072Z-LRWAN1 board with the I-CUBE-LRWAN1 software with the End Node code or the AT SLAVE code.

For the AT_SLAVE code, I used a terminal to send AT COMMAND to the MCU of my LoRa module.

Now, I want to configure my B-L072Z board with the AT_SLAVE code (as I realized before) but send AT_COMMAND with a Nucleo_L073RZ board with the AT_MASTER code (and not with a terminal). In comparison with this picture, I don't have application module and my AT_master module will be a the Nucleo_L073RZ board.

Is it possible? Is the AT_MASTER code functionnal with a Murata LoRa module? 

Should I just connect Tx-> Rx and Rx_>Tx and GND of the two board to communicate (UART) or there is some modification with jumper?

Thanks in advance!

Max

[Tesla DeLorean]

Posted on May 26, 2017 at 14:24

>>Is it possible?

Yes, but is complicated on the NUCLEO and DISCO boards as the USART are connected to the ST-LINK/VCP. You will need to review the schematics to determine the connectivity and solder-bridges, and disconnect the USARTx_RX pin from being driven by the ST-LINK.

The DISCO is designed for you to implement the entire LoRa app, and thus avoid the need to go via the AT command protocol.

[maxence forget]

Posted on May 29, 2017 at 11:33

Thanks for you reply.

I tried to connect my Tx and Rx to the PA9 and PA10 of my DISCO board (it seems to be connected to the LoRa module in the schematics) but without success.

If a communication with USART is too complicated, is it more simple to use I2C or SPI with this DISCO board?

Is there another board with LoRa module to realize the setup that I have described in my first message?

Max

[Tesla DeLorean]

Posted on May 29, 2017 at 16:16

I don't believe it is too complicated, but does require an appreciation about the connectivity, and software/pins. I would expect I2C and SPI to be viable paths, but require more code ownership and change.

The original AT command firmware is expecting to use the USART via PA2/PA3 (LPUSART1), using a different USART on PA9/PA10 (USART1) will require adjustments in the code.

[Dhaval Parikh]

Posted on July 31, 2017 at 22:01

forget.maxence

, This might be too late for you, but it might be helpful for others who want to interface the Murata module on the

B-L072Z-LRWAN1

board with a micro-controller (uC) using the UART used in the AT_Slave example.

As

Turvey.Clive.002

‌ said, it can be done by removing solder bridges. To be specific (from the

B-L072Z-LRWAN1 schematics)

, if you remove the SB28 and SB29 solder bridges, then it disconnects the Rx and Tx lines from the ST-Link and you can use them directly for interfacing with a different uC. Should be pretty straightforward.

[Andrew Neil]

Posted on December 19, 2017 at 21:56

Dhaval Parikh wrote:

Should be pretty straightforward.

Indeed it should.

But then so should working out which solder bridges (SB) to remove - it's documented in the User Manual text, and clearly shown on the schematic.