Stuck on discovering services after using Timers

[samkent]

I've got the experimental ble blinky example project on an NRF52 PCA10040 working fine with an added custom characteristic. I can connect, discover and read/write characteristics without any problems.

However once I've added in my LCD code nRF Connect still detects the device and attempts to connect but gets stuck on discovering services. Debugging over JLink I don't think the board is resetting or locking up so I think it must be to do with my use of timers (or possibly a weird SPI glitch?).

I'm using Timer 1 and 2 so that the softdevice can use Timer 0. Do I need to enable Timer 0 manually for the softdevice?

nrf_drv_config.h

/* TIMER */
#define TIMER0_ENABLED 0

#if (TIMER0_ENABLED == 1)
#define TIMER0_CONFIG_FREQUENCY    NRF_TIMER_FREQ_16MHz
#define TIMER0_CONFIG_MODE         TIMER_MODE_MODE_Timer
#define TIMER0_CONFIG_BIT_WIDTH    TIMER_BITMODE_BITMODE_32Bit
#define TIMER0_CONFIG_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW

#define TIMER0_INSTANCE_INDEX      0
#endif

#define TIMER1_ENABLED 1

#if (TIMER1_ENABLED == 1)
#define TIMER1_CONFIG_FREQUENCY    NRF_TIMER_FREQ_16MHz
#define TIMER1_CONFIG_MODE         TIMER_MODE_MODE_Timer
#define TIMER1_CONFIG_BIT_WIDTH    TIMER_BITMODE_BITMODE_16Bit
#define TIMER1_CONFIG_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW

#define TIMER1_INSTANCE_INDEX      (TIMER0_ENABLED)
#endif

#define TIMER2_ENABLED 1

#if (TIMER2_ENABLED == 1)
#define TIMER2_CONFIG_FREQUENCY    NRF_TIMER_FREQ_16MHz
#define TIMER2_CONFIG_MODE         TIMER_MODE_MODE_Timer
#define TIMER2_CONFIG_BIT_WIDTH    TIMER_BITMODE_BITMODE_16Bit
#define TIMER2_CONFIG_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW

#define TIMER2_INSTANCE_INDEX      (TIMER1_ENABLED+TIMER0_ENABLED)
#endif

LCD

// VCOM Timer
uint32_t time_ms = 12; //Time(in milliseconds) between consecutive compare events.
uint32_t time_ticks;
const nrf_drv_timer_t TIMER_VCOM = NRF_DRV_TIMER_INSTANCE(1);

// Initial VCOM value
uint8_t vcom = 0x00;

// Screen Refresh Timer
uint32_t screen_time_ms = 1000; //Time(in milliseconds) between consecutive compare events.
uint32_t screen_time_ticks;
const nrf_drv_timer_t TIMER_SCREEN_REFRESH = NRF_DRV_TIMER_INSTANCE(2);

/**
* @brief Initiate LCD
*/
void lcdInit(void){

  SEGGER_RTT_WriteString(0, "LCD Init.. ");

  // Set Up CS Pin for LCD
  nrf_gpio_cfg_output(24);

  // Set Up SPI
  nrf_drv_spi_config_t config = NRF_DRV_SPI_DEFAULT_CONFIG(0);

  config.frequency = NRF_DRV_SPI_FREQ_1M;
  config.mode      = NRF_DRV_SPI_MODE_0;
  config.bit_order = NRF_DRV_SPI_BIT_ORDER_MSB_FIRST;

  err_code = nrf_drv_spi_init(&m_spi_master_0, &config, NULL);

  // Set Up Timer To Toggle VCOM
  err_code = nrf_drv_timer_init(&TIMER_VCOM, NULL, toggle_vcom);
  time_ticks = nrf_drv_timer_ms_to_ticks(&TIMER_VCOM, time_ms);
  nrf_drv_timer_extended_compare(&TIMER_VCOM, NRF_TIMER_CC_CHANNEL1, time_ticks, NRF_TIMER_SHORT_COMPARE1_CLEAR_MASK, true);

  // Set Up Timer To Refresh Screen
  err_code = nrf_drv_timer_init(&TIMER_SCREEN_REFRESH, NULL, refreshDisplay);
  screen_time_ticks = nrf_drv_timer_ms_to_ticks(&TIMER_SCREEN_REFRESH, screen_time_ms);
  nrf_drv_timer_extended_compare(&TIMER_SCREEN_REFRESH, NRF_TIMER_CC_CHANNEL2, screen_time_ticks, NRF_TIMER_SHORT_COMPARE2_CLEAR_MASK, true);

  // Enable timers
  // Enable VCOM toggle
  nrf_drv_timer_enable(&TIMER_VCOM);
  // Enable Screen Refresh
  nrf_drv_timer_enable(&TIMER_SCREEN_REFRESH);

  // Send init Commands to LCD
  uint8_t lcdInitCommands[] = {0x60, 0x00};
  nrf_gpio_pin_set(24);
  nrf_drv_spi_transfer(&m_spi_master_0, lcdInitCommands, 2, NULL, 0);
  nrf_gpio_pin_clear(24);

  SEGGER_RTT_WriteString(0, "Done \n");

}

[samkent]

If I comment out nrf_drv_timer_enable() bluetooth works fine Are the timers blocking the softdevice in some way?

[Hung Bui]

Hi Samkent,

You don't need to enable Timer 0 in the driver configuration.

Have you made sure the assertion handler was not called ? Did your device advertise back when it's disconnected ?

Have you checked the disconnect reason when your receive BLE_GAP_EVT_DISCONNECTED event ?

Could you capture a sniffer trace so that we can investigate what happened over the air ?

[samkent]

Fixed it by changing the timer frequencies in my config file.

Lowering the frequency to 125kHz is accurate for my needs and BLE works fine.

#define TIMER1_CONFIG_FREQUENCY    NRF_TIMER_FREQ_125kHz