Is my RAK3172 dead?

[joch (Johann)]

Hi,

I’ve been working with RAK ​​modules for a few weeks, I’m happy to post on the forum today.

We have a range of Sigfox sensors that we want to migrate to LoRaWAN.

To simplify my first developments, I use the RAK3172 module (on a custom PCB) and RUI3.

I encounter a problem when I flash the module. I would like to point out that this module was reflashed several times with complete erasure of the memory after incorrect handling on my part (UART2 was no longer accessible).

Today, when I flash the module, it seems that the module crashes while running the setup.

Here is my test program (simple GPIO test):

#define LED1        PA8     // Test
#define LED2        PA9     // Test
#define VREFON_PIN  PA1     // Voltage ref activation
#define INT_PIN     PA0     // RTC Interrupt 

void setup()
{
    Serial.begin(115200);
    delay(5000);

    Serial1.begin(115200);

    Serial1.println("--------------");
    Serial1.println(PA8);
    Serial1.println(PA9);
    Serial1.println(PA1);
    Serial1.println(PA0);
    Serial1.println("--------------");

    pinMode(LED1, OUTPUT);
    pinMode(LED2, OUTPUT);
    pinMode(VREFON_PIN, OUTPUT);

    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(VREFON_PIN, LOW);

    Serial.println("Go !");
}

void loop()
{
    Serial1.println("HIGH");
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);
    digitalWrite(VREFON_PIN, HIGH);

    delay(1000);

    Serial1.println("LOW");
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(VREFON_PIN, LOW);
}

When running I have no output on UART2.

On UART1, the first information is displayed then a sort of crash dump appears:

---

8
9
1
0

HIGH
LOW
HIGH
–stm32wle5xx▒▒▒Y\RAKwireless RAK3172@------------------------------------------------------=▒=H▒▒▒▒▒▒sҖ"s▒▒▒k▒[▒▒Y▒A
▒▒▒E▒I▒▒n▒▒▒ⷛT▒F▒x▒r8Cț▒▒0O▒▒-▒^▒▒3J▒d▒▒8▒▒9)W▒▒▒ù▒▒)▒ ▒▒a▒ٶ▒▒▒|s▒4▒p▒▒T
JOiĿ▒)▒▒▒▒:▒▒ߺ:▒:D▒▒▒▒1N▒▒Г3▒)▒ȷ▒▒▒▒y ▒l}▒▒`A▒O▒▒LC$2▒▒▒▒v▒▒▒▒W0
7▒▒[4 ▒7▒Z▒"▒▒ q▒G▒Z▒▒
O▒▒-▒g#,
~w$▒▒▒▒▒

From this moment, it is impossible to deploy a new program (“can not get the baudrate”).

I have reflashed the RAK3172-E_latest_final.hex firmware several times but the module does not work any better.

I’m afraid my module is broken.

Can you tell me what’s wrong or confirm that the module is dead?

Thanks,

Joch

[beegee (Bernd Giesecke)]

Welcome to the forum @joch

I had cases where some internal registers of the STM32WLE5 got messed up and the RAK3172 showed weird behaviour.

You can try the following:

Install STM32CubeProgrammer
Pull BOOT0 to GND
Power up the module
In STM32CubeProgrammer, connect to the module
In the Erasing & Programming tab select Full chip erase
After erasing, try to flash the standard RUI3 firmware and see if the module is back to life.

Full Chip Erase will as well erase all production settings, so you need to setup the device after this with its DevEUI, AppEUI, … again.
You can save these settings then with AT+FACTORY as factory default settings.

[Dizmann]

check voltage not 5V only 3.3

[joch (Johann)]

As I explained in my message, I had already tried to completely erase and flash the RUI3 firmware with STM32CubeProgrammer but without success.

I did it again a few tmes using ST-LINK connection, now the module is responding correctly.

Thanks for your help.

Joch