add configurable fanpower for simwind and new PWM sketch (#37)

2026-04-03 18:03:08 -04:00
parent 10c172d3e1
commit 581163c00b
8 changed files with 252 additions and 4 deletions
@@ -0,0 +1,56 @@
+#include "simwind.h"
+
+// ============================================================
+// Configuration
+// ============================================================
+#define BAUD_RATE       115200
+#define PWM_PIN_1       9       // Fan PWM output pins
+#define PWM_PIN_2       10      //
+#define PWM_MAX         320     // Max PWM value for 25kHz (16MHz / 25kHz / 2)
+#define SPEED_MIN       0       // Min speed (mph) — fans off below this
+#define SPEED_MAX       100     // Max speed (mph) — full fan speed at this
+#define SPEED_THRESHOLD 5       // Below this speed fans are off
+// ============================================================
+
+#define BYTE_SIZE sizeof(SimWindData)
+
+int velocity = 0;
+int fanpower = 0;
+
+void setup() {
+    Serial.begin(BAUD_RATE);
+
+    // Configure Timer1 for Phase Correct PWM at 25kHz duty cycle
+    // Mode 10: Phase Correct PWM, TOP = ICR1
+    // WGM13:WGM12:WGM11:WGM10 = 1:0:1:0
+    TCCR1A = _BV(COM1A1) | _BV(COM1B1) | _BV(WGM11);
+    TCCR1B = _BV(WGM13) | _BV(CS10);   // <-- WGM13 restored, no prescaler
+    ICR1 = PWM_MAX;                      // TOP = 320 → 16MHz / (2 * 320) = 25kHz
+    pinMode(PWM_PIN_1, OUTPUT);
+    pinMode(PWM_PIN_2, OUTPUT);
+    OCR1A = 0;
+    OCR1B = 0;
+}
+
+void loop() {
+    char buff[BYTE_SIZE];
+    if (Serial.available() >= BYTE_SIZE) {
+        if (Serial.readBytes(buff, BYTE_SIZE) != BYTE_SIZE) return;
+        union { SimWindData data; char bytes[BYTE_SIZE]; } u;
+        memcpy(u.bytes, buff, BYTE_SIZE);
+        velocity = u.data.velocity;
+        fanpower = u.data.fanpower;
+    }
+
+    int pwm = 0;
+    if (velocity > SPEED_THRESHOLD) {
+        // Square root scaling for slightly stronger sensation at lower speeds
+        // fanpower (0-255) scales the overall intensity
+        float powerScale = (float)fanpower / 255.0;
+        pwm = (int)(sqrt((float)velocity / SPEED_MAX) * PWM_MAX * powerScale);
+        pwm = constrain(pwm, 0, PWM_MAX);
+    }
+
+    OCR1A = pwm;
+    OCR1B = pwm;
+}