Arm Mbed and Pelion Device Management support forum

SX1272MB2xAS not working with TTN

Hi,

I’m trying to use the lora shield SX1272MB2xAS with a Nucleo F429ZI and connect it to the things network and it’s not working.
I use the mbed-os-example-lorawan .
I already use this example with a disco L072CZ LRWAN1 and it connect to TTN without any problems.
To use the SX1272MB2xAS, I have modified the mbed_app.json with the folowing configuration:

{

"config": {

    "lora-radio": {

        "help": "Which radio to use (options: SX126X, SX1272, SX1276) -- See config/ dir for example configs",

        "value": "SX1272"

    },

    "main_stack_size":     { "value": 4096 },

    "lora-spi-mosi":       { "value": "NC" },

    "lora-spi-miso":       { "value": "NC" },

    "lora-spi-sclk":       { "value": "NC" },

    "lora-cs":             { "value": "NC" },

    "lora-reset":          { "value": "NC" },

    "lora-dio0":           { "value": "NC" },

    "lora-dio1":           { "value": "NC" },

    "lora-dio2":           { "value": "NC" },

    "lora-dio3":           { "value": "NC" },

    "lora-dio4":           { "value": "NC" },

    "lora-dio5":           { "value": "NC" },

    "lora-rf-switch-ctl1": { "value": "NC" },

    "lora-rf-switch-ctl2": { "value": "NC" },

    "lora-txctl":          { "value": "NC" },

    "lora-rxctl":          { "value": "NC" },

    "lora-ant-switch":     { "value": "NC" },

    "lora-pwr-amp-ctl":    { "value": "NC" },

    "lora-tcxo":           { "value": "NC" }

},

"target_overrides": {

    "*": {

        "mbed-trace.enable": true,

        "platform.stdio-convert-newlines": true,

        "platform.stdio-baud-rate": 115200,

        "platform.default-serial-baud-rate": 115200,

        "lora.over-the-air-activation": true,

        "lora.duty-cycle-on": true,

        "lora.phy": "EU868",

        "lora.device-eui": "{My device EUI }",

        "lora.application-eui": "{ My App EUI }",

        "lora.application-key": "{ My App key }"

    },

    "K64F": {

        "lora-spi-mosi":       "D11",

        "lora-spi-miso":       "D12",

        "lora-spi-sclk":       "D13",

        "lora-cs":             "D10",

        "lora-reset":          "A0",

        "lora-dio0":           "D2",

        "lora-dio1":           "D3",

        "lora-dio2":           "D4",

        "lora-dio3":           "D5",

        "lora-dio4":           "D8",

        "lora-dio5":           "D9",

        "lora-rf-switch-ctl1": "NC",

        "lora-rf-switch-ctl2": "NC",

        "lora-txctl":          "NC",

        "lora-rxctl":          "NC",

        "lora-ant-switch":     "A4",

        "lora-pwr-amp-ctl":    "NC",

        "lora-tcxo":           "NC"

    },

    "NUCLEO_F429ZI": {

        "lora-radio":          "SX1272",

        "lora-spi-mosi":       "D11",

        "lora-spi-miso":       "D12",

        "lora-spi-sclk":       "D13",

        "lora-cs":             "D10",

        "lora-reset":          "A0",

        "lora-dio0":           "D2",

        "lora-dio1":           "D3",

        "lora-dio2":           "D4",

        "lora-dio3":           "D5",

        "lora-dio4":           "NC",

        "lora-dio5":           "NC",

        "lora-rf-switch-ctl1": "NC",

        "lora-rf-switch-ctl2": "NC",

        "lora-txctl":          "NC",

        "lora-rxctl":          "NC",

        "lora-ant-switch":     "NC",

        "lora-pwr-amp-ctl":    "NC",

        "lora-tcxo":           "NC",

        "target.d11_configuration": "PB_5"

    },


},

"macros": ["MBEDTLS_USER_CONFIG_FILE=\"mbedtls_lora_config.h\""]

}

When I start the program with the trace enable, it seems to work, I get some debug message transmission complete but the OTAA doesn’t work and I’am never connected with TTN.

Is there a bug with the library or should I do something else?

Thank’s in advance for your replies

Hi,
I investigated the problem a bit more and I see that the output power delivered by the board is only -40dBm. Is it possible that I have to configure something in the software or is it a HW problem?