260 lines
6.9 KiB
C++
260 lines
6.9 KiB
C++
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void peak_mean(uint16_t *i2s_buffer, uint32_t len, float *max_value, float *min_value, float *pt_mean)
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{
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max_value[0] = i2s_buffer[0];
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min_value[0] = i2s_buffer[0];
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mean_filter filter(5);
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filter.init(i2s_buffer[0]);
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float mean = 0;
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for (uint32_t i = 1; i < len; i++)
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{
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float value = filter.filter((float)i2s_buffer[i]);
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if (value > max_value[0])
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max_value[0] = value;
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if (value < min_value[0])
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min_value[0] = value;
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mean += i2s_buffer[i];
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}
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mean /= float(BUFF_SIZE);
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mean = to_voltage(mean);
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pt_mean[0] = mean;
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}
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// true if digital/ false if analog
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bool digital_analog(uint16_t *i2s_buffer, uint32_t max_v, uint32_t min_v)
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{
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uint32_t upper_threshold = max_v - 0.05 * (max_v - min_v);
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uint32_t lower_threshold = min_v + 0.05 * (max_v - min_v);
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uint32_t digital_data = 0;
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uint32_t analog_data = 0;
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for (uint32_t i = 0; i < BUFF_SIZE; i++)
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{
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if (i2s_buffer[i] > lower_threshold)
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{
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if (i2s_buffer[i] > upper_threshold)
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{
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// HIGH DIGITAL
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digital_data++;
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}
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else
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{
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// ANALOG/TRANSITION
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analog_data++;
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}
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}
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else
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{
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// LOW DIGITAL
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digital_data++;
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}
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}
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// more than 50% of data is analog
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if (analog_data < digital_data)
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return true;
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return false;
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}
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void trigger_freq_analog(uint16_t *i2s_buffer,
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float sample_rate,
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float mean,
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uint32_t max_v,
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uint32_t min_v,
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float *pt_freq,
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float *pt_period,
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uint32_t *pt_trigger0,
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uint32_t *pt_trigger1)
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{
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float freq = 0;
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float period = 0;
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bool signal_side = false;
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uint32_t trigger_count = 0;
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uint32_t trigger_num = 10;
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uint32_t trigger_temp[trigger_num] = {0};
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uint32_t trigger_index = 0;
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// get initial signal relative to the mean
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if (to_voltage(i2s_buffer[0]) > mean)
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{
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signal_side = true;
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}
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// waveform repetitions calculation + get triggers time
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uint32_t wave_center = (max_v + min_v) / 2;
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for (uint32_t i = 1; i < BUFF_SIZE; i++)
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{
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if (signal_side && i2s_buffer[i] < wave_center - (wave_center - min_v) * 0.2)
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{
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signal_side = false;
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}
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else if (!signal_side && i2s_buffer[i] > wave_center + (max_v - wave_center) * 0.2)
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{
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freq++;
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if (trigger_count < trigger_num)
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{
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trigger_temp[trigger_count] = i;
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trigger_count++;
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}
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signal_side = true;
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}
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}
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// frequency calculation
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if (trigger_count < 2)
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{
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trigger_temp[0] = 0;
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trigger_index = 0;
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freq = 0;
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period = 0;
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}
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else
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{
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// simple frequency calculation fair enough for frequencies over 2khz (20hz resolution)
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freq = freq * 1000 / 50;
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period = (float)(sample_rate * 1000.0) / freq; // us
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// from 2000 to 80 hz -> uses mean of the periods for precision
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if (freq < 2000 && freq > 80)
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{
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period = 0;
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for (uint32_t i = 1; i < trigger_count; i++)
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{
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period += trigger_temp[i] - trigger_temp[i - 1];
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}
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period /= (trigger_count - 1);
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freq = sample_rate * 1000 / period;
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}
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// under 80hz, single period for frequency calculation
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else if (trigger_count > 1 && freq <= 80)
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{
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period = trigger_temp[1] - trigger_temp[0];
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freq = sample_rate * 1000 / period;
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}
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}
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// setting triggers offset and getting second trigger for debug cursor on drawn_channel1
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/*
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The trigger function uses a rise porcentage (5%) obove the mean, thus,
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the real waveform starting point is some datapoints back.
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The resulting trigger gets a negative offset of 5% of the calculated period
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*/
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uint32_t trigger2 = 0;
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if (trigger_temp[0] - period * 0.05 > 0 && trigger_count > 1)
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{
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trigger_index = trigger_temp[0] - period * 0.05;
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trigger2 = trigger_temp[1] - period * 0.05;
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}
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else if (trigger_count > 2)
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{
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trigger_index = trigger_temp[1] - period * 0.05;
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if (trigger_count > 2)
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trigger2 = trigger_temp[2] - period * 0.05;
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}
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pt_trigger0[0] = trigger_index;
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pt_trigger1[0] = trigger2;
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pt_freq[0] = freq;
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pt_period[0] = period;
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}
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void trigger_freq_digital(uint16_t *i2s_buffer,
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float sample_rate,
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float mean,
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uint32_t max_v,
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uint32_t min_v,
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float *pt_freq,
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float *pt_period,
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uint32_t *pt_trigger0)
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{
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float freq = 0;
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float period = 0;
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bool signal_side = false;
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uint32_t trigger_count = 0;
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uint32_t trigger_num = 10;
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uint32_t trigger_temp[trigger_num] = {0};
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uint32_t trigger_index = 0;
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// get initial signal relative to the mean
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if (to_voltage(i2s_buffer[0]) > mean)
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{
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signal_side = true;
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}
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// waveform repetitions calculation + get triggers time
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uint32_t wave_center = (max_v + min_v) / 2;
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bool normal_high = (mean > to_voltage(wave_center)) ? true : false;
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if (max_v - min_v > 4095 * (0.4 / 3.3))
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{
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for (uint32_t i = 1; i < BUFF_SIZE; i++)
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{
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if (signal_side && i2s_buffer[i] < wave_center - (wave_center - min_v) * 0.2)
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{
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// signal was high, fell -> trigger if normal high
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if (trigger_count < trigger_num && normal_high)
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{
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trigger_temp[trigger_count] = i;
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trigger_count++;
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}
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signal_side = false;
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}
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else if (!signal_side && i2s_buffer[i] > wave_center + (max_v - wave_center) * 0.2)
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{
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freq++;
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// signal was low, rose -> trigger if normal low
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if (trigger_count < trigger_num && !normal_high)
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{
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trigger_temp[trigger_count] = i;
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trigger_count++;
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}
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signal_side = true;
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}
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}
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freq = freq * 1000 / 50;
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period = (float)(sample_rate * 1000.0) / freq; // us
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if (trigger_count > 1)
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{
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// from 2000 to 80 hz -> uses mean of the periods for precision
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if (freq < 2000 && freq > 80)
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{
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period = 0;
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for (uint32_t i = 1; i < trigger_count; i++)
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{
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period += trigger_temp[i] - trigger_temp[i - 1];
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}
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period /= (trigger_count - 1);
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freq = sample_rate * 1000 / period;
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}
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// under 80hz, single period for frequency calculation
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else if (trigger_count > 1 && freq <= 80)
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{
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period = trigger_temp[1] - trigger_temp[0];
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freq = sample_rate * 1000 / period;
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}
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}
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trigger_index = trigger_temp[0];
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if (trigger_index > 10)
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trigger_index -= 10;
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else
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trigger_index = 0;
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}
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pt_trigger0[0] = trigger_index;
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pt_freq[0] = freq;
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pt_period[0] = period;
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}
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