PulseGen/speed_tables: cleanup constants

src/config/config.h

@@ -1,7 +1,6 @@
 #pragma once
 #include <stdint.h>
 #include "axis.h"
-#include "todo.h"
 
 /// Wrangler for assorted compile-time configuration and constants.
 namespace config {
@@ -33,6 +32,15 @@ static constexpr const uint8_t buttonsADCIndex = 0; ///< ADC index of buttons in
 /// microstepping interval.
 static constexpr uint8_t uStepMaxRes = 32;
 
+/// Do not plan moves equal or shorter than the requested steps
+static constexpr uint8_t dropSegments = 0;
+
+/// Max step frequency 40KHz
+static constexpr uint16_t maxStepFrequency = 40000;
+
+/// Minimum stepping rate 120Hz
+static constexpr uint16_t minStepRate = 120;
+
 /// Idler configuration
 static constexpr AxisConfig idler = {
     .dirOn = true,

src/config/todo.h

@@ -1,14 +0,0 @@
-#pragma once
-
-#ifndef __AVR__
-    #define F_CPU 16000000
-#endif
-
-// Max step frequency 40KHz
-#define MAX_STEP_FREQUENCY 40000
-
-// Minimum stepper rate 120Hz.
-#define MINIMAL_STEP_RATE 120
-
-// Step frequency divider (influences the speed tables!)
-#define STEP_TIMER_DIVIDER 8

src/hal/cpu.h

@@ -5,6 +5,11 @@
 namespace hal {
 namespace cpu {
 
+#ifndef F_CPU
+    /// Main clock frequency
+    #define F_CPU (16000000ul)
+#endif
+
 /// CPU init routines (not really necessary for the AVR)
 void Init();
 

src/modules/pulse_gen.cpp

@@ -9,16 +9,15 @@ using modules::speed_table::calc_timer;
 namespace modules {
 namespace pulse_gen {
 
-PulseGen::PulseGen() {
+PulseGen::PulseGen(steps_t max_jerk, steps_t acceleration) {
-    // Some initial values
+    // Axis status
     position = 0;
-    acceleration = 1200;
+    this->max_jerk = max_jerk;
+    this->acceleration = acceleration;
+
+    // Block buffer
     block_buffer_head = block_buffer_tail = 0;
     current_block = nullptr;
-
-    // TODO: configuration constants
-    dropsegments = 5;
-    max_jerk = 100;
 }
 
 void PulseGen::CalculateTrapezoid(block_t *block, steps_t entry_speed, steps_t exit_speed) {
@@ -28,12 +27,12 @@ void PulseGen::CalculateTrapezoid(block_t *block, steps_t entry_speed, steps_t e
     rate_t final_rate = exit_speed;
 
     // Limit minimal step rate (Otherwise the timer will overflow.)
-    if (initial_rate < MINIMAL_STEP_RATE)
+    if (initial_rate < config::minStepRate)
-        initial_rate = MINIMAL_STEP_RATE;
+        initial_rate = config::minStepRate;
     if (initial_rate > block->nominal_rate)
         initial_rate = block->nominal_rate;
-    if (final_rate < MINIMAL_STEP_RATE)
+    if (final_rate < config::minStepRate)
-        final_rate = MINIMAL_STEP_RATE;
+        final_rate = config::minStepRate;
     if (final_rate > block->nominal_rate)
         final_rate = block->nominal_rate;
 
@@ -100,7 +99,7 @@ void PulseGen::Move(pos_t target, steps_t feed_rate) {
     block->steps = abs(target - position);
 
     // Bail if this is a zero-length block
-    if (block->steps <= dropsegments)
+    if (block->steps <= config::dropSegments)
         return;
 
     // Direction and speed for this block
@@ -109,7 +108,7 @@ void PulseGen::Move(pos_t target, steps_t feed_rate) {
 
     // Acceleration of the segment, in steps/sec^2
     block->acceleration = acceleration;
-    block->acceleration_rate = block->acceleration * (rate_t)((float)F_CPU / (F_CPU / STEP_TIMER_DIVIDER));
+    block->acceleration_rate = block->acceleration * (rate_t)((float)F_CPU / (F_CPU / speed_table::cpuFrequencyDivider));
 
     // Perform the trapezoid calculations
     CalculateTrapezoid(block, max_jerk, max_jerk);

src/modules/pulse_gen.h

@@ -15,7 +15,7 @@ typedef int32_t pos_t; ///< Axis position (signed)
 
 class PulseGen {
 public:
-    PulseGen();
+    PulseGen(steps_t max_jerk, steps_t acceleration);
 
     /// @returns the acceleration for the axis
     steps_t Acceleration() const { return acceleration; };
@@ -59,11 +59,6 @@ private:
         rate_t acceleration; ///< acceleration steps/sec^2
     };
 
-    //{ units constants
-    steps_t max_jerk;
-    steps_t dropsegments; // segments are dropped if lower than that
-    //}
-
     // Block buffer parameters
     block_t block_buffer[2];
     block_t *current_block;
@@ -72,6 +67,7 @@ private:
 
     // Axis data
     pos_t position; ///< Current axis position
+    steps_t max_jerk; ///< Axis jerk (could be constant)
     steps_t acceleration; ///< Current axis acceleration
 
     // Step parameters

src/modules/speed_table.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "../config/config.h"
 #include "../hal/progmem.h"
+#include "../hal/cpu.h"
 #include "math.h"
 
 namespace modules {
@@ -10,6 +11,11 @@ namespace speed_table {
 
 typedef uint16_t st_timer_t;
 
+/// CPU timer frequency divider required for the speed tables
+static constexpr uint8_t cpuFrequencyDivider = 8;
+static_assert(F_CPU / cpuFrequencyDivider == 2000000,
+    "speed tables not compatible for the requested frequency");
+
 /// Lookup table for rates equal or higher than 8*256
 extern const st_timer_t speed_table_fast[256][2] PROGMEM;
 
@@ -18,8 +24,8 @@ extern const st_timer_t speed_table_slow[256][2] PROGMEM;
 
 /// Calculate the next timer interval and steps according to current step rate
 static inline st_timer_t calc_timer(st_timer_t step_rate, uint8_t &step_loops) {
-    if (step_rate > MAX_STEP_FREQUENCY)
+    if (step_rate > config::maxStepFrequency)
-        step_rate = MAX_STEP_FREQUENCY;
+        step_rate = config::maxStepFrequency;
     if (step_rate > 20000) { // If steprate > 20kHz >> step 4 times
         step_rate = (step_rate >> 2) & 0x3fff;
         step_loops = 4;
@@ -51,8 +57,9 @@ static inline st_timer_t calc_timer(st_timer_t step_rate, uint8_t &step_loops) {
         timer -= ((pm::read_word(table_address + 1) * (uint8_t)(step_rate & 0x0007)) >> 3);
     }
     if (timer < 100) {
+        // 20kHz this should never happen
         timer = 100;
-    } // 20kHz this should never happen
+    }
     return timer;
 }
 

tests/unit/modules/pulse_gen/test_pulse_gen.cpp

@@ -18,8 +18,7 @@ TEST_CASE("pulse_gen::basic", "[pulse_gen]") {
     };
 
     for (int accel = 100; accel <= 5000; accel *= 2) {
-        PulseGen pg;
+        PulseGen pg(10, accel);
-        pg.SetAcceleration(accel);
         pg.Move(100000, 10000);
 
         unsigned long ts = 0;