Multiple IPC channels

[Robert de Brum]

Hello,

Referencing this link here, I am looking for any updates to using IPC for some custom inter-core communication WHILE ALSO running Bluetooth on an nrf5340.

Long story short, I have a project with custom code for both the cpu_app and cpu_net cores of an nrf5340, and I am looking for a way to communicate between both. Right now, the cpu_net code is running the hci_rpmsg sample so that I can use BLE from the application core. I have not found a clean way to modify this to provide some hooks for my custom use case, nor do I want to try.

If there are any updates on being able to use a custom IPC channel and BLE at the same time, or if IPC is not the right abstraction layer to go through, please let me know! The link I provided mention using the BTS but I am not sure how that is relevant or possible.

I know that there are some complex structures being put to use here and I have tried to spend some time learning it but perhaps there is an easy-to-follow overview of inter-process communication that shows us how IPC, RMPSG, ICMSG, MBOX, shared SRAM and all other abstraction layers play together.

Thank you much.

[Robert de Brum]

I am still getting the same crash as before. Here is what I am doing in the BLE app (cpu_app main.c file).

Note this code runs AFTER the ble_ready callback is hit.

Any other ideas on what is causing this crash? I am iterating through my code to toggle different sections/features to narrow down what might be causing the crash.

[Sigurd]

I tested it with the peripheral_lbs example, and did not see a crash.

Here is how and where in the main() I added it: (cpu_app main.c file)

int main(void)
{
	int blink_status = 0;
	int err;

	printk("Starting Bluetooth Peripheral LBS example\n");

	err = dk_leds_init();
	if (err) {
		printk("LEDs init failed (err %d)\n", err);
		return 0;
	}

	err = init_button();
	if (err) {
		printk("Button init failed (err %d)\n", err);
		return 0;
	}

	if (IS_ENABLED(CONFIG_BT_LBS_SECURITY_ENABLED)) {
		err = bt_conn_auth_cb_register(&conn_auth_callbacks);
		if (err) {
			printk("Failed to register authorization callbacks.\n");
			return 0;
		}

		err = bt_conn_auth_info_cb_register(&conn_auth_info_callbacks);
		if (err) {
			printk("Failed to register authorization info callbacks.\n");
			return 0;
		}
	}

	err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return 0;
	}

	printk("Bluetooth initialized\n");

	if (IS_ENABLED(CONFIG_SETTINGS)) {
		settings_load();
	}

	err = bt_lbs_init(&lbs_callbacs);
	if (err) {
		printk("Failed to init LBS (err:%d)\n", err);
		return 0;
	}

	err = bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad),
			      sd, ARRAY_SIZE(sd));
	if (err) {
		printk("Advertising failed to start (err %d)\n", err);
		return 0;
	}

	printk("Advertising successfully started\n");

	sync_timer_init();

	sync_timer_repeated_configure(1000000);

	synchronized_start_init();
	k_msleep(1000);
	synchronized_start_activate();



	for (;;) {
		dk_set_led(RUN_STATUS_LED, (++blink_status) % 2);
		k_sleep(K_MSEC(RUN_LED_BLINK_INTERVAL));
	}
}

[Robert de Brum]

Thanks for this. I validated your sample then I was able to integrate it into my project pretty well.

This will be very helpful moving forward. My question now is that I will need a little bit of shared data to go back and forth. Up to 6 bytes.

This does not need to be triggered in the backend with DPPI or other peripherals. It can look more like the RPC sample - however I also struggled with this alongside BLE.

First of all, is RPC the correct one to use? This is what I wanted to get to work: developer.nordicsemi.com/.../README.html

[Sigurd]

Hi!

Robert de Brum said:

Thanks for this. I validated your sample then I was able to integrate it into my project pretty well.

Great!

Robert de Brum said:

First of all, is RPC the correct one to use?

It looks to fulfill your use-case. Only thing I can think of right now for why it should not work with BLE, is that there could be a conflict with SDC/MPSL and the entropy driver. Maybe try to send some predefined bytes instead of random ones gathered from the entropy driver.