diff --git a/Marlin/src/HAL/HAL_LPC1768/HAL.cpp b/Marlin/src/HAL/HAL_LPC1768/HAL.cpp
index 71315fdfde85d2812da3c02ef72ab67c91b858a6..64b90ab1d5d7d4eda972793e45b8595b9e6a7d5c 100644
--- a/Marlin/src/HAL/HAL_LPC1768/HAL.cpp
+++ b/Marlin/src/HAL/HAL_LPC1768/HAL.cpp
@@ -22,11 +22,6 @@
#include "../../inc/MarlinConfig.h"
-extern "C" {
- //#include <lpc17xx_adc.h>
- //#include <lpc17xx_pinsel.h>
-}
-
HalSerial usb_serial;
// U8glib required functions
@@ -112,7 +107,6 @@ void HAL_adc_enable_channel(int ch) {
};
}
-uint8_t active_adc = 0;
void HAL_adc_start_conversion(const uint8_t ch) {
if (analogInputToDigitalPin(ch) == -1) {
SERIAL_PRINTF("HAL: HAL_adc_start_conversion: invalid channel %d\n", ch);
@@ -122,7 +116,6 @@ void HAL_adc_start_conversion(const uint8_t ch) {
LPC_ADC->ADCR &= ~0xFF; // Reset
SBI(LPC_ADC->ADCR, ch); // Select Channel
SBI(LPC_ADC->ADCR, 24); // Start conversion
- active_adc = ch;
}
bool HAL_adc_finished(void) {
@@ -130,44 +123,131 @@ bool HAL_adc_finished(void) {
}
// possible config options if something similar is extended to more platforms.
-#define ADC_USE_MEDIAN_FILTER // filter out erroneous readings
-#define ADC_USE_LOWPASS_FILTER // filter out high frequency noise
-#define ADC_LOWPASS_K_VALUE 4 // how much to smooth out noise (1:8)
+#define ADC_USE_MEDIAN_FILTER // Filter out erroneous readings
+#define ADC_MEDIAN_FILTER_SIZE (23) // Higher values increase step delay (phase shift),
+ // (ADC_MEDIAN_FILTER_SIZE + 1) / 2 sample step delay (12 samples @ 500Hz: 24ms phase shift)
+ // Memory usage per ADC channel (bytes): (6 * ADC_MEDIAN_FILTER_SIZE) + 16
+ // 8 * ((6 * 23) + 16 ) = 1232 Bytes for 8 channels
+
+#define ADC_USE_LOWPASS_FILTER // Filter out high frequency noise
+#define ADC_LOWPASS_K_VALUE (6) // Higher values increase rise time
+ // Rise time sample delays for 100% signal convergence on full range step
+ // (1 : 13, 2 : 32, 3 : 67, 4 : 139, 5 : 281, 6 : 565, 7 : 1135, 8 : 2273)
+ // K = 6, 565 samples, 500Hz sample rate, 1.13s convergence on full range step
+ // Memory usage per ADC channel (bytes): 4 (32 Bytes for 8 channels)
+
+// Sourced from https://embeddedgurus.com/stack-overflow/tag/median-filter/
struct MedianFilter {
- uint16_t values[3];
- uint8_t next_val;
- MedianFilter() {
- next_val = 0;
- values[0] = values[1] = values[2] = 0;
+ #define STOPPER 0 // Smaller than any datum
+ struct Pair {
+ Pair *point; // Pointers forming list linked in sorted order
+ uint16_t value; // Values to sort
+ };
+
+ Pair buffer[ADC_MEDIAN_FILTER_SIZE] = {}; // Buffer of nwidth pairs
+ Pair *datpoint = buffer; // Pointer into circular buffer of data
+ Pair small = {NULL, STOPPER}; // Chain stopper
+ Pair big = {&small, 0}; // Pointer to head (largest) of linked list.
+
+ uint16_t update(uint16_t datum) {
+ Pair *successor; // Pointer to successor of replaced data item
+ Pair *scan; // Pointer used to scan down the sorted list
+ Pair *scanold; // Previous value of scan
+ Pair *median; // Pointer to median
+ uint16_t i;
+
+ if (datum == STOPPER) {
+ datum = STOPPER + 1; // No stoppers allowed.
+ }
+
+ if ( (++datpoint - buffer) >= ADC_MEDIAN_FILTER_SIZE) {
+ datpoint = buffer; // Increment and wrap data in pointer.
+ }
+
+ datpoint->value = datum; // Copy in new datum
+ successor = datpoint->point; // Save pointer to old value's successor
+ median = &big; // Median initially to first in chain
+ scanold = NULL; // Scanold initially null.
+ scan = &big; // Points to pointer to first (largest) datum in chain
+
+ // Handle chain-out of first item in chain as special case
+ if (scan->point == datpoint) {
+ scan->point = successor;
+ }
+ scanold = scan; // Save this pointer and
+ scan = scan->point ; // step down chain
+
+ // Loop through the chain, normal loop exit via break.
+ for (i = 0 ; i < ADC_MEDIAN_FILTER_SIZE; ++i) {
+ // Handle odd-numbered item in chain
+ if (scan->point == datpoint) {
+ scan->point = successor; // Chain out the old datum
+ }
+
+ if (scan->value < datum) { // If datum is larger than scanned value
+ datpoint->point = scanold->point; // Chain it in here
+ scanold->point = datpoint; // Mark it chained in
+ datum = STOPPER;
+ }
+
+ // Step median pointer down chain after doing odd-numbered element
+ median = median->point; // Step median pointer
+ if (scan == &small) {
+ break; // Break at end of chain
+ }
+ scanold = scan; // Save this pointer and
+ scan = scan->point; // step down chain
+
+ // Handle even-numbered item in chain.
+ if (scan->point == datpoint) {
+ scan->point = successor;
+ }
+
+ if (scan->value < datum) {
+ datpoint->point = scanold->point;
+ scanold->point = datpoint;
+ datum = STOPPER;
+ }
+
+ if (scan == &small) {
+ break;
+ }
+
+ scanold = scan;
+ scan = scan->point;
+ }
+ return median->value;
}
+};
+
+struct LowpassFilter {
+ uint32_t data_delay = 0;
uint16_t update(uint16_t value) {
- values[next_val++] = value;
- next_val = next_val % 3;
- return max(min(values[0], values[1]), min(max(values[0], values[1]), values[2])); //median
+ data_delay = data_delay - (data_delay >> ADC_LOWPASS_K_VALUE) + value;
+ return (uint16_t)(data_delay >> ADC_LOWPASS_K_VALUE);
}
};
-uint16_t lowpass_filter(uint16_t value) {
- const uint8_t k_data_shift = ADC_LOWPASS_K_VALUE;
- static uint32_t data_delay[NUM_ANALOG_INPUTS] = { 0 };
- uint32_t &active_filter = data_delay[active_adc];
- active_filter = active_filter - (active_filter >> k_data_shift) + value;
- return (uint16_t)(active_filter >> k_data_shift);
-}
-
uint16_t HAL_adc_get_result(void) {
- uint32_t data = LPC_ADC->ADGDR;
- CBI(LPC_ADC->ADCR, 24); // Stop conversion
- if (data & ADC_OVERRUN) return 0;
+ uint32_t adgdr = LPC_ADC->ADGDR;
+ CBI(LPC_ADC->ADCR, 24); // Stop conversion
+
+ if (adgdr & ADC_OVERRUN) return 0;
+ uint16_t data = (adgdr >> 4) & 0xFFF; // copy the 12bit data value
+ uint8_t adc_channel = (adgdr >> 24) & 0x7; // copy the 3bit used channel
+
#ifdef ADC_USE_MEDIAN_FILTER
static MedianFilter median_filter[NUM_ANALOG_INPUTS];
- data = median_filter[active_adc].update((uint16_t)data);
+ data = median_filter[adc_channel].update(data);
#endif
+
#ifdef ADC_USE_LOWPASS_FILTER
- data = lowpass_filter((uint16_t)data);
+ static LowpassFilter lowpass_filter[NUM_ANALOG_INPUTS];
+ data = lowpass_filter[adc_channel].update(data);
#endif
- return ((data >> 6) & 0x3ff); // 10bit
+
+ return ((data >> 2) & 0x3ff); // return 10bit value as Marlin expects
}
#define SBIT_CNTEN 0
@@ -187,8 +267,8 @@ void HAL_pwm_init(void) {
LPC_PWM1->TCR = _BV(SBIT_CNTEN) | _BV(SBIT_PWMEN);
LPC_PWM1->PR = 0x0; // No prescalar
LPC_PWM1->MCR = _BV(SBIT_PWMMR0R); // Reset on PWMMR0, reset TC if it matches MR0
- LPC_PWM1->MR0 = 255; /* set PWM cycle(Ton+Toff)=255) */
- LPC_PWM1->MR5 = 0; /* Set 50% Duty Cycle for the channels */
+ LPC_PWM1->MR0 = 255; // set PWM cycle(Ton+Toff)=255)
+ LPC_PWM1->MR5 = 0; // Set 50% Duty Cycle for the channels
LPC_PWM1->MR6 = 0;
// Trigger the latch Enable Bits to load the new Match Values MR0, MR5, MR6
diff --git a/Marlin/src/HAL/HAL_LPC1768/HAL_LCD_pin_routines.c b/Marlin/src/HAL/HAL_LPC1768/HAL_LCD_pin_routines.c
index f4e5a76b47306b0cddc1de6a7c2d670ce99b95b7..0146c4fb678503a4a7870e3f9a391f17b6427d9a 100644
--- a/Marlin/src/HAL/HAL_LPC1768/HAL_LCD_pin_routines.c
+++ b/Marlin/src/HAL/HAL_LPC1768/HAL_LCD_pin_routines.c
@@ -34,7 +34,7 @@
#include <LPC17xx.h>
#include <lpc17xx_pinsel.h>
-#include "src/core/macros.h"
+#include "../../src/core/macros.h"
//#include "pinmapping.h"
#define LPC_PORT_OFFSET (0x0020)
diff --git a/Marlin/src/module/temperature.h b/Marlin/src/module/temperature.h
index 147a2df24f31bc4c5c3dcf913e058cb2c4d6aa6c..dc2b7010478f5d720db58cae7a46991057bff2ee 100644
--- a/Marlin/src/module/temperature.h
+++ b/Marlin/src/module/temperature.h
@@ -90,7 +90,7 @@ enum ADCSensorState {
#if HAS_PID_HEATING
#define PID_K2 (1.0-PID_K1)
- #define PID_dT ((OVERSAMPLENR * float(ACTUAL_ADC_SAMPLES)) / (F_CPU / 64.0 / 256.0))
+ #define PID_dT ((OVERSAMPLENR * float(ACTUAL_ADC_SAMPLES)) / TEMP_TIMER_FREQUENCY)
// Apply the scale factors to the PID values
#define scalePID_i(i) ( (i) * PID_dT )