Immediate Panic on Portenta H7 M4 Core

[trylaarsdam]

I'm trying to use BLE on the Portenta H7 M4 core (which I believe should be possible since the M4 has access to the HCI UART lines, but if someone knows definitively that it is not possible please let me know), however when I include the library, and flash to the Portenta, when I call BLE.begin(); from the M4 core, it immediately causes an MbedOS panic.

Here's a sample that is reproducible on my end:

// M4 Core
#include "Arduino.h"
#include "ArduinoBLE.h"

void setup() {
     BLE.begin(); // panics
}
void loop() {

}

There are mentions to the M4 core in the library and no mentions in Arduino's docs that the M4 core is not able to perform BLE operations, so any pointers or suggestions on how to initialize the BLE radio from the M4 core would be appreciated.

[facchinm]

Fix is WIP here #331

[trylaarsdam]

Fantastic, good to know.

[trylaarsdam]

@aentinger Just tested this again since it was merged and this issue is not fixed on the Portenta. The board doesn't immediately panic now, but it just freezes on HCI.begin() which is called by BLE.begin()

Here is my source code which should provide an easy test case to reproduce. This is with the src folder of the current master branch of this repo in my src folder.

#ifdef CORE_CM4
#include <Arduino.h>
// includes from BLE lib 
#include "utility/ATT.h"
#include "utility/HCI.h"
#include "utility/GAP.h"
#include "utility/GATT.h"
#include "utility/L2CAPSignaling.h" 
#include "local/BLELocalDevice.h"
#define BT_REG_ON PJ_12
void setup()
{
	pinMode(LEDB, OUTPUT);
	pinMode(LED_BUILTIN, OUTPUT);
	digitalWrite(LED_BUILTIN, HIGH);
	digitalWrite(LEDB, HIGH);

	// from BLE.begin()
	pinMode(BT_REG_ON, OUTPUT);
	digitalWrite(BT_REG_ON, LOW);
	delay(500);
	digitalWrite(BT_REG_ON, HIGH);
	delay(500);

	if (!HCI.begin())
	{
		// never reached
		digitalWrite(LED_BUILTIN, LOW);
	}

	// BLE.begin continues here, but it doesn't get here anyway...

	// never reached
	digitalWrite(LEDB, LOW);
}

void loop()
{
}

#endif

#ifdef CORE_CM7
#include <Arduino.h>

void setup()
{
	bootM4();
}

void loop()
{
}
#endif

I've also reproduced this issue in the Arduino IDE, by locally cloning this library and simply including ArduinoBLE.h and calling BLE.begin() on the M4 core.

[facchinm]

@trylaarsdam can you try #353 on top of current master branch? In the M4 refactor we did indeed miss some defines and the module was never turned on on Portenta

[trylaarsdam]

@facchinm unfortunately no change in behavior when I use your branch. When on the M4 core BLE.begin still freezes indefinitely when HCI.begin is called.