Device seems to crash when adding new BLE service

[sorceressofmaths]

I've been trying to add a new BLE service to my device. I've followed the instructions in this tutorial, up to step 7 (so no characteristics or anything), but the device is not advertising. In fact, the software seems to fail entirely; it does not seem to make it past the advertising_init and services_init functions in the initialization sequence. (In main() the device is supposed to blink an LED after this sequence is finished, which it does not.)

I've done nothing to modify the code other than these changes specified in the tutorial. The software compiles and loads on the device without any warnings or errors. I've posted the relevant code below; let me know if you need any more information.

// main.c

static ble_uuid_t m_adv_uuids[] = {{BLE_UUID_HEART_RATE_SERVICE,         BLE_UUID_TYPE_BLE},
																	 {BLE_UUID_BATTERY_SERVICE,            BLE_UUID_TYPE_BLE},
																	 {BLE_UUID_DEVICE_INFORMATION_SERVICE, BLE_UUID_TYPE_BLE},
																	 {BLE_UUID_OUR_SERVICE, BLE_UUID_TYPE_VENDOR_BEGIN}};
ble_os_t m_our_service;

static void services_init(void) {

	uint32_t       err_code;
	ble_hrs_init_t hrs_init;
	ble_bas_init_t bas_init;
	ble_dis_init_t dis_init;
	uint8_t        body_sensor_location;

	// Initialize Heart Rate Service.
	body_sensor_location = BLE_HRS_BODY_SENSOR_LOCATION_FINGER;

	memset(&hrs_init, 0, sizeof(hrs_init));

	hrs_init.evt_handler                 = NULL;
	hrs_init.is_sensor_contact_supported = true;
	hrs_init.p_body_sensor_location      = &body_sensor_location;

	// Here the sec level for the Heart Rate Service can be changed/increased.
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&hrs_init.hrs_hrm_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_hrm_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_hrm_attr_md.write_perm);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&hrs_init.hrs_bsl_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&hrs_init.hrs_bsl_attr_md.write_perm);

	err_code = ble_hrs_init(&m_hrs, &hrs_init);
	APP_ERROR_CHECK(err_code);

	// Initialize Battery Service.
	memset(&bas_init, 0, sizeof(bas_init));

	// Here the sec level for the Battery Service can be changed/increased.
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_char_attr_md.cccd_write_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_char_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_char_attr_md.write_perm);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&bas_init.battery_level_report_read_perm);

	bas_init.evt_handler          = NULL;
	bas_init.support_notification = true;
	bas_init.p_report_ref         = NULL;
	bas_init.initial_batt_level   = 100;

	err_code = ble_bas_init(&m_bas, &bas_init);
	APP_ERROR_CHECK(err_code);

	// Initialize Device Information Service.
	memset(&dis_init, 0, sizeof(dis_init));

	ble_srv_ascii_to_utf8(&dis_init.manufact_name_str, (char *)MANUFACTURER_NAME);

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&dis_init.dis_attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&dis_init.dis_attr_md.write_perm);

	err_code = ble_dis_init(&dis_init);
	APP_ERROR_CHECK(err_code);

	#ifdef BLE_DFU_APP_SUPPORT
		/** @snippet [DFU BLE Service initialization] */
		ble_dfu_init_t   dfus_init;

		// Initialize the Device Firmware Update Service.
		memset(&dfus_init, 0, sizeof(dfus_init));

		dfus_init.evt_handler   = dfu_app_on_dfu_evt;
		dfus_init.error_handler = NULL;
		dfus_init.evt_handler   = dfu_app_on_dfu_evt;
		dfus_init.revision      = DFU_REVISION;

		err_code = ble_dfu_init(&m_dfus, &dfus_init);
		APP_ERROR_CHECK(err_code);
		
		dfu_app_reset_prepare_set(reset_prepare);
		dfu_app_dm_appl_instance_set(m_app_handle);
		
		our_service_init(&m_our_service);
		/** @snippet [DFU BLE Service initialization] */
	#endif // BLE_DFU_APP_SUPPORT
}

static void advertising_init(void) {
    
    ble_advdata_t srdata;
    memset(&srdata, 0, sizeof(srdata));
    srdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    srdata.uuids_complete.p_uuids = m_adv_uuids;

	uint32_t      err_code;
	ble_advdata_t advdata;

	// Build advertising data struct to pass into @ref ble_advertising_init.
	memset(&advdata, 0, sizeof(advdata));

	advdata.name_type               = BLE_ADVDATA_FULL_NAME;
	advdata.include_appearance      = true;
	advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
	advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
	advdata.uuids_complete.p_uuids  = m_adv_uuids;

	ble_adv_modes_config_t options = {0};
	options.ble_adv_slow_enabled  = BLE_ADV_SLOW_ENABLED;
	options.ble_adv_slow_interval = APP_ADV_INTERVAL;
	options.ble_adv_slow_timeout  = APP_ADV_TIMEOUT_IN_SECONDS;

	err_code = ble_advertising_init(&advdata, &srdata, &options, on_adv_evt, NULL);
	APP_ERROR_CHECK(err_code);
}

int main(void){

	uint32_t err_code;
	
	SEGGER_RTT_WriteString(0, "Exectuing program.\n");

	timers_init();
	ble_stack_init();
	device_manager_init(1);   // i set erase_bonds to 1 so the embedivet won't do that annoying thing where it refuses to bond with the central after you change the central's firmware
	gap_params_init();
	services_init();
	advertising_init();
	conn_params_init();

	setupPins();

	nrf_gpio_pin_write(MODE, 1); //enable the load switch

	flashGreen();  // test green led
	twi_init();    // initialize the i2c bus
	ledFlash();    // indicate success
	rtcSetup();    // reach out to the accelerometer
	ledFlash();    // indicate success
	
	// Run the rest of the program; the code never makes it to this point
}

// our_service.h

#ifndef OUR_SERVICE_H__
#define OUR_SERVICE_H__

#include <stdint.h>
#include "ble.h"
#include "ble_srv_common.h"

#define BLE_UUID_OUR_BASE_UUID {{0x23, 0xD1, 0x13, 0xEF, 0x5F, 0x78, 0x23, 0x15, 0xDE, 0xEF, 0x12, 0x12, 0x00, 0x00, 0x00, 0x00}} // 128-bit base UUID
#define BLE_UUID_OUR_SERVICE 0xABCD // Just a random, but recognizable value

/**
 * @brief This structure contains various status information for our service. 
 * It only holds one entry now, but will be populated with more items as we go.
 * The name is based on the naming convention used in Nordic's SDKs. 
 * 'ble’ indicates that it is a Bluetooth Low Energy relevant structure and 
 * ‘os’ is short for Our Service). 
 */
typedef struct
{
    uint16_t    service_handle;     /**< Handle of Our Service (as provided by the BLE stack). */
}ble_os_t;

/**@brief Function for initializing our new service.
 *
 * @param[in]   p_our_service       Pointer to Our Service structure.
 */
void our_service_init(ble_os_t * p_our_service);

#endif  /* _ OUR_SERVICE_H__ */

// our_service.c

#include <stdint.h>
#include <string.h>
#include "our_service.h"
#include "ble_srv_common.h"
#include "app_error.h"
#include "SEGGER_RTT.h"

/**@brief Function for initiating our new service.
 *
 * @param[in]   p_our_service        Our Service structure.
 *
 */
void our_service_init(ble_os_t * p_our_service)
{
    // STEP 3: Declare 16 bit service and 128 bit base UUIDs and add them to BLE stack table     
    uint32_t err_code;
    ble_uuid_t service_uuid;
    ble_uuid128_t base_uuid = BLE_UUID_OUR_BASE_UUID;
    service_uuid.uuid = BLE_UUID_OUR_SERVICE;
    err_code = sd_ble_uuid_vs_add(&base_uuid, &service_uuid.type);
    APP_ERROR_CHECK(err_code);
    
    // STEP 4: Add our service
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY,
                                    &service_uuid,
                                    &p_our_service->service_handle);
    APP_ERROR_CHECK(err_code);
    
    // Print messages to Segger Real Time Terminal
    // UNCOMMENT THE FOUR LINES BELOW AFTER INITIALIZING THE SERVICE OR THE EXAMPLE WILL NOT COMPILE.
    SEGGER_RTT_WriteString(0, "Exectuing our_service_init().\n"); // Print message to RTT to the application flow
    SEGGER_RTT_printf(0, "Service UUID: 0x%#04x\n", service_uuid.uuid); // Print service UUID should match definition BLE_UUID_OUR_SERVICE
    SEGGER_RTT_printf(0, "Service UUID type: 0x%#02x\n", service_uuid.type); // Print UUID type. Should match BLE_UUID_TYPE_VENDOR_BEGIN. Search for BLE_UUID_TYPES in ble_types.h for more info
    SEGGER_RTT_printf(0, "Service handle: 0x%#04x\n", p_our_service->service_handle); // Print out the service handle. Should match service handle shown in MCP under Attribute values
}

[bjorn-spockeli]

Generally, whenever you're seeing that the nRF device is not advertising after you flashed you should do the following:

1. Start a debug session
2. Set a breakpoint in app_error_handler_bare in app_error.c
3. Run the code and if you end up in the error handler, examine the call stack and identify the function that caused the error.
4. Look up the error code in the SDK/SoftDevice API documentation on http://infocenter.nordicsemi.com/

Most likely you've not allocated enough RAM to the SoftDevice or you've passed incorrect parameters to the SoftDevice. 

Best regards

Bjørn

[sorceressofmaths]

Hello Bjorn,

It appears that I've not allocated enough RAM to the softdevice. How do I adjust this in SDK 11? All the tutorials I can find so far are for later SDK versions. (We plan to port our software to SDK 15 in a few weeks, but at the moment we're on a tight deadline and don't have time to do the port just yet.)

[bjorn-spockeli]

If you're using Keil then this is done under Options for Target -> Target -> Read/Write Memory Areas. 

Increase the IRAM1 Start address and decrease the size accordingly, i.e. so that IRAM1 Start + IRAM1 Size <= Total RAM on your nRF5x device. 

If you're using make and GCC you'll have to modify the linker script, i.e. the RAM Origin and Length

MEMORY
{
    FLASH (rx) : ORIGIN = 0x1c000, LENGTH = 0x64000
    RAM (rwx) : ORIGIN = 0x20002080, LENGTH = 0xdf80
}

[sorceressofmaths]

I don't quite understand. If I want to increase the amount of memory allocated, shouldn't I decrease the origin and increase the length? Also, is there a good rule of thumb for how much extra memory to allocate for a new service?

[bjorn-spockeli]

You want to decrease the RAM allocated to the application, by increasing the origin( also the end address of the SoftDevice RAM section). So you're effectivly increasing the size of the SoftDevice RAM section by increasing the application RAM origin. 

No, its a trial and error process so you'll have to increase move the origin upwards until the sd_ble_enable() call does not return the NO_MEM error code. We added a second parameter in the sd_ble_enable() call in S132 v3.0.0 which returns the application RAM origin for the configuration passed to the SoftDevice. 

[sorceressofmaths]

Hello Bjorn,
Once I started increasing the memory a bit, I started getting no error message (it was never hitting the breakpoint), and the device started pushing through RTT

"sd_ble_enable: ram_start should be adjusted to 0x20001fe8

RAM length should be adjusted to 0xe018"

When I tried adjusting it to those values, it simply started printing "sd_ble_enable: RAM START at 0x20001FE8" before restarting the program from the beginning.

It still doesn't hit the breakpoint in app_error.c, and it still isn't advertising.

[bjorn-spockeli]

Which SDK version are you using? The tutorial you're using is based on SDK v11.0.0 and the SoftDevices compatible with this SDK does not return the ram_start address.