Standalone ESB without MPSL isn't working

[douglas.malnati]

For reference I am using NCS v2.0 and VSCode NCS plugin programming in C++.

I am trying to get the example ESB TX example working from the nordic sample (link).

(Notably I replaced the logging with my own logging code and stripped out the LED indications).

However, when I run the code, it crashes repeatedly, giving the following output:

Enhanced ShockBurst ptx sample
HF clock started
Initialization complete
Sending test packet
MPSL ASSERT: 112, 2189

I configured an MPSL assert handler which is how I determined the MPSL was crashing out.

I have my full code and prj.conf file below.

Can you give any guidance on what I'm doing wrong?  I have a lot of features enabled in my prj.conf because I'm separately working on many other aspects of a large application which I want to incorporate ESB into.  That includes Bluetooth, which perhaps is activating MPSL and a source of contention here?

Please let me know what I would need to change in order for this to work.

Code:

#include <zephyr/drivers/clock_control.h>
#include <zephyr/drivers/clock_control/nrf_clock_control.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/irq.h>
#include <zephyr/logging/log.h>
#include <nrf.h>
#include <esb.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/kernel.h>
#include <zephyr/types.h>

#include "Log.h"


static bool ready = true;
static struct esb_payload rx_payload;
inline static struct esb_payload tx_payload = {
     .length = 8,
     .pipe = 0,
     .data = { 0x01, 0x00, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 }
};

#define _RADIO_SHORTS_COMMON                                                   \
	(RADIO_SHORTS_READY_START_Msk | RADIO_SHORTS_END_DISABLE_Msk |         \
	 RADIO_SHORTS_ADDRESS_RSSISTART_Msk |                                  \
	 RADIO_SHORTS_DISABLED_RSSISTOP_Msk)

void event_handler(struct esb_evt const *event)
{
	ready = true;

	switch (event->evt_id) {
	case ESB_EVENT_TX_SUCCESS:
		Log("TX SUCCESS EVENT");
		break;
	case ESB_EVENT_TX_FAILED:
		Log("TX FAILED EVENT");
		break;
	case ESB_EVENT_RX_RECEIVED:
		while (esb_read_rx_payload(&rx_payload) == 0) {
			Log("Packet received, len %d : "
				"0x%02x, 0x%02x, 0x%02x, 0x%02x, "
				"0x%02x, 0x%02x, 0x%02x, 0x%02x",
				rx_payload.length, rx_payload.data[0],
				rx_payload.data[1], rx_payload.data[2],
				rx_payload.data[3], rx_payload.data[4],
				rx_payload.data[5], rx_payload.data[6],
				rx_payload.data[7]);
		}
		break;
	}
}

int clocks_start(void)
{
	int err;
	int res;
	struct onoff_manager *clk_mgr;
	struct onoff_client clk_cli;

	clk_mgr = z_nrf_clock_control_get_onoff(CLOCK_CONTROL_NRF_SUBSYS_HF);
	if (!clk_mgr) {
		Log("Unable to get the Clock manager");
		return -ENXIO;
	}

	sys_notify_init_spinwait(&clk_cli.notify);

	err = onoff_request(clk_mgr, &clk_cli);
	if (err < 0) {
		Log("Clock request failed: %d", err);
		return err;
	}

	do {
		err = sys_notify_fetch_result(&clk_cli.notify, &res);
		if (!err && res) {
			Log("Clock could not be started: %d", res);
			return res;
		}
	} while (err);

	Log("HF clock started");
	return 0;
}

int esb_initialize(void)
{
	int err;
	/* These are arbitrary default addresses. In end user products
	 * different addresses should be used for each set of devices.
	 */
	uint8_t base_addr_0[4] = {0xE7, 0xE7, 0xE7, 0xE7};
	uint8_t base_addr_1[4] = {0xC2, 0xC2, 0xC2, 0xC2};
	uint8_t addr_prefix[8] = {0xE7, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8};

	struct esb_config config = ESB_DEFAULT_CONFIG;

	config.protocol = ESB_PROTOCOL_ESB_DPL;
	config.retransmit_delay = 600;
	config.bitrate = ESB_BITRATE_2MBPS;
	config.event_handler = event_handler;
	config.mode = ESB_MODE_PTX;
	config.selective_auto_ack = true;

	err = esb_init(&config);

	if (err) {
		return err;
	}

	err = esb_set_base_address_0(base_addr_0);
	if (err) {
		return err;
	}

	err = esb_set_base_address_1(base_addr_1);
	if (err) {
		return err;
	}

	err = esb_set_prefixes(addr_prefix, ARRAY_SIZE(addr_prefix));
	if (err) {
		return err;
	}

	return 0;
}


void main(void)
{
	int err;

	Log("Enhanced ShockBurst ptx sample");

	err = clocks_start();
	if (err) {
		return;
	}

	err = esb_initialize();
	if (err) {
		Log("ESB initialization failed, err %d", err);
		return;
	}

	Log("Initialization complete");
	Log("Sending test packet");

	tx_payload.noack = false;
	while (1) {
		if (ready) {
			ready = false;
			esb_flush_tx();

			err = esb_write_payload(&tx_payload);
			if (err) {
				Log("Payload write failed, err %d", err);
			}
			tx_payload.data[1]++;
		}
		k_sleep(K_MSEC(100));
	}
}

prj.conf:

#####################################################################
# set up project to use c++17 and useful libs/stl
#####################################################################
CONFIG_CPLUSPLUS=y
CONFIG_LIB_CPLUSPLUS=y
CONFIG_NEWLIB_LIBC=y
CONFIG_STD_CPP20=y
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
CONFIG_CBPRINTF_FP_SUPPORT=y


#####################################################################
# maximum debugging - my code, kernel, everything
#####################################################################
CONFIG_DEBUG_OPTIMIZATIONS=y
CONFIG_DEBUG=y
CONFIG_DEBUG_THREAD_INFO=y
CONFIG_EXCEPTION_STACK_TRACE=y
CONFIG_DEBUG_INFO=y

#####################################################################
# system features
#####################################################################

# Enable rebooting by code
CONFIG_REBOOT=y

# use internal RC oscillator instead of external 32KHz crystal
# speeds up boot time
# in my case, going from infinity down to instant
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

# Disable NFC so I can use the GPIO pins
CONFIG_NFCT_PINS_AS_GPIOS=y

# monitor high-water mark on stack by placing known-values in stack
# buffer before running
CONFIG_INIT_STACKS=y
CONFIG_MPU_STACK_GUARD=y


#####################################################################
# Set up interfacing
#####################################################################
# I want serial enabled in general
CONFIG_SERIAL=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_ASYNC_API=y

# I want logging to function
CONFIG_LOG=y

# I want to use the serial interface for logging
# but when I enable shell, this makes printf'd material come out twice,
# once normally, and another time with the shell prefix.
# so I'm disabling it for now.
# CONFIG_LOG_BACKEND_UART=y

# I want synchronous logging (no queue and print later)
CONFIG_LOG_MODE_IMMEDIATE=y

# I want to be able to influnce what gets logged at runtime (via shell)
CONFIG_LOG_RUNTIME_FILTERING=y

# I want the default to be that every module prints all levels
# 0 = off
# 1 = error
# 2 = error and warning
# 3 = error and warning and info
# 4 = error and warning and info and debug
CONFIG_LOG_DEFAULT_LEVEL=4

# show function name in output
CONFIG_LOG_FUNC_NAME_PREFIX_ERR=y
CONFIG_LOG_FUNC_NAME_PREFIX_WRN=y
CONFIG_LOG_FUNC_NAME_PREFIX_INF=y
CONFIG_LOG_FUNC_NAME_PREFIX_DBG=y

# color it
CONFIG_LOG_BACKEND_SWO=y
CONFIG_LOG_BACKEND_SHOW_COLOR=y

# redirect printk to the log
# I am disabling this, because when shell enabled, prink output was
# prefixed with shell.  now I see it on serial with no prefix.
#CONFIG_LOG_PRINTK=y




# ##### Shell #####

# # I want the shell interface to operate
CONFIG_SHELL=y




#####################################################################
# set up stats
#####################################################################
CONFIG_THREAD_RUNTIME_STATS=y




#####################################################################
# set up pwm
#####################################################################
CONFIG_PWM=y


#####################################################################
# set up usb
#####################################################################
# CONFIG_USB_DEVICE_STACK=y
# CONFIG_USB_DEVICE_PRODUCT="Glow Bike"
# CONFIG_USB_MASS_STORAGE=y


#####################################################################
# set up disk
#####################################################################

# CONFIG_DISK_ACCESS=y
# CONFIG_DISK_DRIVERS=y


# CONFIG_FLASH=y
# CONFIG_DISK_DRIVER_FLASH=y


# CONFIG_FLASH_MAP=y
# CONFIG_FLASH_PAGE_LAYOUT=y
# CONFIG_MPU_ALLOW_FLASH_WRITE=y


# CONFIG_FILE_SYSTEM=y
# CONFIG_FAT_FILESYSTEM_ELM=y
# CONFIG_FS_FATFS_READ_ONLY=n
# CONFIG_FS_FATFS_MOUNT_MKFS=y




#####################################################################
# set multi-protocol service layer (multiple radio protocol support)
#####################################################################
# enable multi-protocol service layer (doesn't work with CONFIG_BT_LL_SW_SPLIT seemingly)
CONFIG_MPSL=y
# limit to 1 for now, that's all I'm using atm
CONFIG_MPSL_TIMESLOT_SESSION_COUNT=2
# let's see during dev
CONFIG_MPSL_LOG_LEVEL_DBG=y
# allow myself to catch assert errors in my own code (and still die)
CONFIG_MPSL_ASSERT_HANDLER=y

#####################################################################
# set up ble
#####################################################################
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048
CONFIG_BT_RX_STACK_SIZE=4096
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_BT=y
CONFIG_BT_HCI=y
CONFIG_BT_CTLR=y
# Use the zephyr BLE implementation instead of the SoftDevice from Nordic
# CONFIG_BT_LL_SW_SPLIT=y



CONFIG_BT_PERIPHERAL=y
CONFIG_BT_CENTRAL=y
CONFIG_BT_BROADCASTER=y
CONFIG_BT_OBSERVER=y

# Enable Security Manager Protocol (SMP), making it possible to pair devices over LE
CONFIG_BT_SMP=y

# allow me to set the code to show to users on their device via bt_passkey_set()
CONFIG_BT_FIXED_PASSKEY=y

# let me see more details about the other side of the connection
CONFIG_BT_REMOTE_INFO=y

# let me change and see changes to the PHY layer
CONFIG_BT_USER_PHY_UPDATE=y

# let me change and see changes to the data length (MTU?)
CONFIG_BT_USER_DATA_LEN_UPDATE=y

# let me express preferences for phy modulation
CONFIG_BT_CTLR_PHY_CODED=y
# CONFIG_BT_HCI_VS_EXT=y
# CONFIG_BT_PHY_UPDATE=y

# let me change (my) and measure (their) transmit power levels
CONFIG_BT_CTLR_CONN_RSSI=y
# CONFIG_BT_CTLR_ADVANCED_FEATURES=y    ; # triggers warning, needed?
CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y
# ?
# CONFIG_BT_TPS=y



#####################################################################
# set up ESB (extended shock burst)
#####################################################################
CONFIG_ESB=y
CONFIG_NCS_SAMPLES_DEFAULTS=y




# fat frames
# https://devzone.nordicsemi.com/f/nordic-q-a/84226/increasing-ble-mtu-data-length-for-notifications-on-ncs-v1-8
# https://github.com/zephyrproject-rtos/zephyr/issues/25648
# Uncoded LE Data Packet Format:
#
# | Preamble | Access  |                           PDU (2 to 257 bytes)                         |   CRC   |
# |          | Address | LL Header |       Link Layer PDU (0 to 251 bytes)           |    MIC   |         |
# |          |         |           | L2CAP Header |      L2CAP PDU (0-247 bytes)     | Optional |         |
# |          |         |           |              |    ATT Header    |  ATT Payload  |          |         |
# |          |         |           |              | OpCode | Handle  |               |          |         |
# |  1 byte  | 4 bytes |  2 bytes  |   4 bytes    | 1 byte | 2 bytes | 0 - 244 bytes | 4 bytes  | 3 bytes |
#
# L2CAP can be larger than 247 bytes, but will be split across multiple LL packets as a result.
# ATT payloads can be larger than 244 bytes, but will be split across multiple LL packets as a result.
# 
#
# Kconfig Symbols:
#     CONFIG_BT_CTLR_DATA_LENGTH_MAX : Maximum payload size of the Link Layer PDU
#     CONFIG_BT_BUF_ACL_TX_SIZE      : Maximum L2CAP PDU is limited to this value - 4
#     CONFIG_BT_BUF_ACL_RX_SIZE      : Maximum L2CAP PDU is limited to this value - 4
#     CONFIG_BT_L2CAP_TX_MTU         : Maximum L2CAP PDU size for transmission
CONFIG_BT_BUF_ACL_RX_SIZE=251
CONFIG_BT_BUF_ACL_TX_SIZE=251
CONFIG_BT_L2CAP_TX_MTU=247
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
# CONFIG_BT_GATT_AUTO_UPDATE_MTU=


CONFIG_BT_GATT_DYNAMIC_DB=y
CONFIG_BT_DEVICE_APPEARANCE_DYNAMIC=y
CONFIG_BT_DEVICE_NAME_DYNAMIC=y


# unsure these
#CONFIG_BT_EXT_ADV=y

CONFIG_PM=n


# settings subsystem required as well for bluetooth libs (for bonding)
CONFIG_BT_SETTINGS=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
CONFIG_NVS=y
CONFIG_SETTINGS=y

# major memory hog, ~2k per connection (wtf)
CONFIG_BT_MAX_CONN=20




#####################################################################
# allow access to flash for read/write (non-volatile memory store)
#####################################################################
# CONFIG_MAIN_STACK_SIZE=2048

# CONFIG_MPU_ALLOW_FLASH_WRITE=y

# CONFIG_FLASH=y
# CONFIG_FLASH_MAP=y
# CONFIG_FLASH_PAGE_LAYOUT=y

# CONFIG_FILE_SYSTEM=y
# CONFIG_FILE_SYSTEM_LITTLEFS=y


#####################################################################
# attempt to get RTT working, but no, still not working
#####################################################################
# CONFIG_USE_SEGGER_RTT=y

#####################################################################
# disable startup banner printed to serial by zephyr
#####################################################################
CONFIG_BOOT_BANNER=n

Thanks.

[Einar Thorsrud]

Hi,

I am a bit confused. In the heading you describe no MPSL, and there is also no reference to MPSL in the code. However, you enable MPSL in the configuration, so MPSL is part of your application. Do you intend to use MPSL or not? If not, set CONFIG_MPSL=n.

If you want to use both Bluetooth and ESB, you will need to use MPSL.  And in that case, you need to ensure that you only use ESB in the granted timeslots and that you clean-up each time before the timeslot ends. See the MPSL timeslot sample. See also this blog post: Updating to the MPSL Timeslot interface.

[douglas.malnati]

Ok I will use MPSL if I have it enabled.

Thank you, no further questions on this, this can be closed.