ULTRASONIC INTERFACE USING TIMER

Hi Dialog,

Our product is obstacle detection for Blind People. To upgrrade to BLE based device we choose DA14531 module.

主要由超声波传感器、蜂鸣器、触觉振动器、电池组成。

I'm trying to interface the following Ultrasonic sensor 400 S/T R 100. To generate 40 KHz burst of pulses, I configured timer 0 without PWM. I created a counter inside ISR of timer to generate transmission pulse. which I did it successfully(Refer attachment). Now after a delay of 1ms inside ISR , I'm calling adc_get_sample() function. From there I determine distance based on ultrasonic sensor principle. After running few iterations in keil debug mode .It got stuck in

static inline void dlg_error_isr(void)
{
ASSERT_WARNING(0);
}

in rwble.cThe project which is choose is BLE Barbone project. I have attached Trigger pulse generated with echo I got when obstacle is placed at 50 cm. As you can see the time interval is 3ms when coverted to distance is approx 51 cm. I have series of queries to implement this in code,

1. I'm not able to read ADC sample inside ISR.

2. What is the accuracy of your ADC ? w.r.to precision in milli voltage.

3. Even when I run an ISR without any above functionality, I'm not able to connect to BLE scanner app.

Timer Configuration

// Enable the Timer0/Timer2 input clock
timer0_2_clk_enable();

timer0_init(TIM0_CLK_FAST, PWM_MODE_ONE, TIM0_CLK_NO_DIV);

// Set the Timer0/Timer2 input clock division factor to 2, so8 MHz input clock
定时器0\u 2\u clk\u div\u set（&clk\u div\u config）；

// reload value for 12.5 micro second(T = 1/8 MHz * RELOAD_12.5_US = 0.125 * 100 = 12.5 micro second)
timer0_set_pwm_on_counter(TIMER_ON);
timer0_set_pwm_high_counter(NO_PWM);
定时器0\设置\脉宽调制\低电平\计数器（无\脉宽调制）；
// register callback function for SWTIM_IRQn irq
timer0_register_callback(burst_user_callback_function);

// enable SWTIM_IRQn irq
timer0_enable_irq();

ADC配置

// adc configuration
adc_offset_calibrate(ADC_INPUT_MODE_SINGLE_ENDED);

adc_config_t echo_pin_cfg =
{
.input_mode = ADC_INPUT_MODE_SINGLE_ENDED,
.input = ADC_INPUT_SE_P0_6,
.smpl_time_mult = 2,
.continuous = false,
.interval_mult = 0,
.input衰减器=ADC\U input\U ATTN\U 4X，
.chopping = false,
.oversampling = 0
};

adc_init(&echo_pin_cfg);

Could you assist me in integrating this sensor. I need to know how can I run a Timer ISR and BLE service at same time ?

当做，

BALAJI