diff --git a/Gaugemover.ino b/Gaugemover.ino
new file mode 100644
index 0000000..a682582
--- /dev/null
+++ b/Gaugemover.ino
@@ -0,0 +1,547 @@
+#include <Arduino.h>
+#include <math.h>
+
+static const uint8_t GAUGE_COUNT = 2;
+
+// For now: commands come over USB serial
+#define CMD_PORT Serial
+#define DEBUG_PORT Serial
+
+struct GaugePins {
+  uint8_t dirPin;
+  uint8_t stepPin;
+  int8_t enablePin;          // -1 if unused
+  bool dirInverted;
+  bool stepActiveHigh;
+  bool enableActiveLow;
+};
+
+GaugePins gaugePins[GAUGE_COUNT] = {
+  // dir, step, en, dirInv, stepHigh, enActiveLow
+  {50, 51, -1, false, true, true},   // Gauge 0
+  {8, 9, -1, true, true, true},   // Gauge 1
+};
+
+enum HomingState : uint8_t {
+  HS_IDLE,
+  HS_START,
+  HS_BACKING,
+  HS_SETTLE,
+  HS_DONE
+};
+
+struct Gauge {
+  long currentPos = 0;
+  long targetPos = 0;
+
+  long minPos = 0;
+  long maxPos = 3610;             // adjust to your usable travel
+  long homingBackoffSteps = 3700; // should exceed reverse travel slightly
+
+  float velocity = 0.0f;
+  float maxSpeed = 8000.0f;
+  float accel = 9000.0f;
+  float homingSpeed = 500.0f;
+
+  float stepAccumulator = 0.0f;
+  unsigned long lastUpdateMicros = 0;
+
+  bool enabled = true;
+  bool homed = false;
+
+  HomingState homingState = HS_IDLE;
+  long homingStepsRemaining = 0;
+  unsigned long homingLastStepMicros = 0;
+  unsigned long homingStateStartMs = 0;
+
+  bool sweepEnabled = false;
+  bool sweepTowardMax = true;
+};
+
+Gauge gauges[GAUGE_COUNT];
+String rxLine;
+
+void sendReply(const String& s) {
+  CMD_PORT.println(s);
+}
+
+float absf(float x) {
+  return (x < 0.0f) ? -x : x;
+}
+
+void setEnable(uint8_t id, bool en) {
+  if (id >= GAUGE_COUNT) return;
+  gauges[id].enabled = en;
+
+  int8_t pin = gaugePins[id].enablePin;
+  if (pin < 0) return;
+
+  bool level = gaugePins[id].enableActiveLow ? !en : en;
+  digitalWrite(pin, level ? HIGH : LOW);
+}
+
+void setDir(uint8_t id, bool forward) {
+  bool level = gaugePins[id].dirInverted ? !forward : forward;
+  digitalWrite(gaugePins[id].dirPin, level ? HIGH : LOW);
+}
+
+void pulseStep(uint8_t id) {
+  bool active = gaugePins[id].stepActiveHigh;
+  digitalWrite(gaugePins[id].stepPin, active ? HIGH : LOW);
+  delayMicroseconds(4);
+  digitalWrite(gaugePins[id].stepPin, active ? LOW : HIGH);
+}
+
+void doStep(uint8_t id, int dir, bool allowPastMin = false) {
+  Gauge& g = gauges[id];
+  if (!g.enabled) return;
+
+  if (dir > 0) {
+    if (g.currentPos >= g.maxPos) return;
+    setDir(id, true);
+    pulseStep(id);
+    g.currentPos++;
+  } else if (dir < 0) {
+    if (!allowPastMin && g.currentPos <= g.minPos) return;
+    setDir(id, false);
+    pulseStep(id);
+    g.currentPos--;
+  }
+}
+
+void requestHome(uint8_t id) {
+  if (id >= GAUGE_COUNT) return;
+  Gauge& g = gauges[id];
+  g.homingState = HS_START;
+  g.homed = false;
+  g.velocity = 0.0f;
+  g.stepAccumulator = 0.0f;
+  g.sweepEnabled = false;
+}
+
+void requestHomeAll() {
+  for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    requestHome(i);
+  }
+}
+
+void updateHoming(uint8_t id) {
+  Gauge& g = gauges[id];
+  unsigned long nowUs = micros();
+  unsigned long nowMs = millis();
+
+  switch (g.homingState) {
+    case HS_IDLE:
+      return;
+
+    case HS_START:
+      g.velocity = 0.0f;
+      g.stepAccumulator = 0.0f;
+      g.homingStepsRemaining = g.homingBackoffSteps;
+      g.homingLastStepMicros = nowUs;
+      g.homingState = HS_BACKING;
+      break;
+
+    case HS_BACKING: {
+      float intervalUs = 1000000.0f / g.homingSpeed;
+      if ((nowUs - g.homingLastStepMicros) >= intervalUs) {
+        g.homingLastStepMicros = nowUs;
+
+        if (g.homingStepsRemaining > 0) {
+          doStep(id, -1, true);
+          g.homingStepsRemaining--;
+        } else {
+          g.homingState = HS_SETTLE;
+          g.homingStateStartMs = nowMs;
+        }
+      }
+      break;
+    }
+
+    case HS_SETTLE:
+      if (nowMs - g.homingStateStartMs >= 100) {
+        g.currentPos = 0;
+        g.targetPos = 0;
+        g.velocity = 0.0f;
+        g.stepAccumulator = 0.0f;
+        g.homed = true;
+        g.homingState = HS_DONE;
+
+        DEBUG_PORT.print("HOMED ");
+        DEBUG_PORT.println(id);
+      }
+      break;
+
+    case HS_DONE:
+      g.homingState = HS_IDLE;
+      break;
+  }
+}
+
+void updateSweepTarget(uint8_t id) {
+  Gauge& g = gauges[id];
+  if (!g.sweepEnabled || !g.homed || g.homingState != HS_IDLE) return;
+
+  if (g.sweepTowardMax) {
+    g.targetPos = g.maxPos;
+    if (g.currentPos >= g.maxPos && absf(g.velocity) < 1.0f) {
+      g.sweepTowardMax = false;
+      g.targetPos = g.minPos;
+    }
+  } else {
+    g.targetPos = g.minPos;
+    if (g.currentPos <= g.minPos && absf(g.velocity) < 1.0f) {
+      g.sweepTowardMax = true;
+      g.targetPos = g.maxPos;
+    }
+  }
+}
+
+void updateGauge(uint8_t id) {
+  Gauge& g = gauges[id];
+
+  if (g.homingState != HS_IDLE) {
+    updateHoming(id);
+    return;
+  }
+
+  if (!g.homed) return;
+
+  if (g.sweepEnabled) {
+    updateSweepTarget(id);
+  }
+
+  unsigned long now = micros();
+  if (g.lastUpdateMicros == 0) {
+    g.lastUpdateMicros = now;
+    return;
+  }
+
+  float dt = (now - g.lastUpdateMicros) / 1000000.0f;
+  g.lastUpdateMicros = now;
+
+  if (dt <= 0.0f || dt > 0.1f) return;
+
+  long error = g.targetPos - g.currentPos;
+
+  if (error == 0 && absf(g.velocity) < 0.01f) {
+    g.velocity = 0.0f;
+    g.stepAccumulator = 0.0f;
+    return;
+  }
+
+  float dir = (error > 0) ? 1.0f : (error < 0 ? -1.0f : 0.0f);
+  float brakingDistance = (g.velocity * g.velocity) / (2.0f * g.accel + 0.0001f);
+
+  if ((float)labs(error) <= brakingDistance) {
+    if (g.velocity > 0.0f) {
+      g.velocity -= g.accel * dt;
+      if (g.velocity < 0.0f) g.velocity = 0.0f;
+    } else if (g.velocity < 0.0f) {
+      g.velocity += g.accel * dt;
+      if (g.velocity > 0.0f) g.velocity = 0.0f;
+    }
+  } else {
+    g.velocity += dir * g.accel * dt;
+    if (g.velocity > g.maxSpeed) g.velocity = g.maxSpeed;
+    if (g.velocity < -g.maxSpeed) g.velocity = -g.maxSpeed;
+  }
+
+  if (fabs(g.velocity) < 0.01f && error != 0) {
+    g.velocity = dir * 5.0f;
+  }
+
+  g.stepAccumulator += g.velocity * dt;
+
+  while (g.stepAccumulator >= 1.0f) {
+    if (g.currentPos == g.targetPos) {
+      g.stepAccumulator = 0.0f;
+      g.velocity = 0.0f;
+      break;
+    }
+
+    doStep(id, +1, false);
+    g.stepAccumulator -= 1.0f;
+
+    if (g.currentPos >= g.maxPos) {
+      g.currentPos = g.maxPos;
+      g.targetPos = g.maxPos;
+      g.velocity = 0.0f;
+      g.stepAccumulator = 0.0f;
+      break;
+    }
+  }
+
+  while (g.stepAccumulator <= -1.0f) {
+    if (g.currentPos == g.targetPos) {
+      g.stepAccumulator = 0.0f;
+      g.velocity = 0.0f;
+      break;
+    }
+
+    doStep(id, -1, false);
+    g.stepAccumulator += 1.0f;
+
+    if (g.currentPos <= g.minPos) {
+      g.currentPos = g.minPos;
+      g.targetPos = g.minPos;
+      g.velocity = 0.0f;
+      g.stepAccumulator = 0.0f;
+      break;
+    }
+  }
+}
+
+bool parseSet(const String& line) {
+  int id;
+  long pos;
+  if (sscanf(line.c_str(), "SET %d %ld", &id, &pos) == 2) {
+    if (id < 0 || id >= GAUGE_COUNT) {
+      sendReply("ERR BAD_ID");
+      return true;
+    }
+
+    Gauge& g = gauges[id];
+    pos = constrain(pos, g.minPos, g.maxPos);
+    g.targetPos = pos;
+    g.sweepEnabled = false;
+    sendReply("OK");
+    return true;
+  }
+  return false;
+}
+
+bool parseSpeed(const String& line) {
+  int firstSpace = line.indexOf(' ');
+  int secondSpace = line.indexOf(' ', firstSpace + 1);
+  if (firstSpace < 0 || secondSpace < 0) return false;
+  if (line.substring(0, firstSpace) != "SPEED") return false;
+
+  int id = line.substring(firstSpace + 1, secondSpace).toInt();
+  float speed = line.substring(secondSpace + 1).toFloat();
+
+  if (id < 0 || id >= GAUGE_COUNT) {
+    sendReply("ERR BAD_ID");
+    return true;
+  }
+  if (speed <= 0.0f) {
+    sendReply("ERR BAD_SPEED");
+    return true;
+  }
+
+  gauges[id].maxSpeed = speed;
+  sendReply("OK");
+  return true;
+}
+
+bool parseAccel(const String& line) {
+  int firstSpace = line.indexOf(' ');
+  int secondSpace = line.indexOf(' ', firstSpace + 1);
+  if (firstSpace < 0 || secondSpace < 0) return false;
+  if (line.substring(0, firstSpace) != "ACCEL") return false;
+
+  int id = line.substring(firstSpace + 1, secondSpace).toInt();
+  float accel = line.substring(secondSpace + 1).toFloat();
+
+  if (id < 0 || id >= GAUGE_COUNT) {
+    sendReply("ERR BAD_ID");
+    return true;
+  }
+  if (accel <= 0.0f) {
+    sendReply("ERR BAD_ACCEL");
+    return true;
+  }
+
+  gauges[id].accel = accel;
+  sendReply("OK");
+  return true;
+}
+
+bool parseEnable(const String& line) {
+  int id, en;
+  if (sscanf(line.c_str(), "ENABLE %d %d", &id, &en) == 2) {
+    if (id < 0 || id >= GAUGE_COUNT) {
+      sendReply("ERR BAD_ID");
+      return true;
+    }
+
+    setEnable(id, en != 0);
+    sendReply("OK");
+    return true;
+  }
+  return false;
+}
+
+bool parseZero(const String& line) {
+  int id;
+  if (sscanf(line.c_str(), "ZERO %d", &id) == 1) {
+    if (id < 0 || id >= GAUGE_COUNT) {
+      sendReply("ERR BAD_ID");
+      return true;
+    }
+
+    Gauge& g = gauges[id];
+    g.currentPos = 0;
+    g.targetPos = 0;
+    g.velocity = 0.0f;
+    g.stepAccumulator = 0.0f;
+    g.homed = true;
+    g.sweepEnabled = false;
+    sendReply("OK");
+    return true;
+  }
+  return false;
+}
+
+bool parseHome(const String& line) {
+  int id;
+  if (sscanf(line.c_str(), "HOME %d", &id) == 1) {
+    if (id < 0 || id >= GAUGE_COUNT) {
+      sendReply("ERR BAD_ID");
+      return true;
+    }
+
+    requestHome(id);
+    sendReply("OK");
+    return true;
+  }
+
+  if (line == "HOMEALL") {
+    requestHomeAll();
+    sendReply("OK");
+    return true;
+  }
+
+  return false;
+}
+
+bool parseSweep(const String& line) {
+  int firstSpace = line.indexOf(' ');
+  int secondSpace = line.indexOf(' ', firstSpace + 1);
+  int thirdSpace = line.indexOf(' ', secondSpace + 1);
+
+  if (firstSpace < 0 || secondSpace < 0 || thirdSpace < 0) return false;
+  if (line.substring(0, firstSpace) != "SWEEP") return false;
+
+  int id = line.substring(firstSpace + 1, secondSpace).toInt();
+  float accel = line.substring(secondSpace + 1, thirdSpace).toFloat();
+  float speed = line.substring(thirdSpace + 1).toFloat();
+
+  if (id < 0 || id >= GAUGE_COUNT) {
+    sendReply("ERR BAD_ID");
+    return true;
+  }
+
+  Gauge& g = gauges[id];
+
+  if (accel <= 0.0f || speed <= 0.0f) {
+    g.sweepEnabled = false;
+    g.velocity = 0.0f;
+    g.stepAccumulator = 0.0f;
+    sendReply("OK");
+    return true;
+  }
+
+  g.accel = accel;
+  g.maxSpeed = speed;
+  g.sweepEnabled = true;
+  g.sweepTowardMax = true;
+  g.targetPos = g.maxPos;
+  sendReply("OK");
+  return true;
+}
+
+bool parsePosQuery(const String& line) {
+  if (line == "POS?") {
+    for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+      CMD_PORT.print("POS ");
+      CMD_PORT.print(i);
+      CMD_PORT.print(' ');
+      CMD_PORT.print(gauges[i].currentPos);
+      CMD_PORT.print(' ');
+      CMD_PORT.print(gauges[i].targetPos);
+      CMD_PORT.print(' ');
+      CMD_PORT.print(gauges[i].homed ? 1 : 0);
+      CMD_PORT.print(' ');
+      CMD_PORT.print((int)gauges[i].homingState);
+      CMD_PORT.print(' ');
+      CMD_PORT.println(gauges[i].sweepEnabled ? 1 : 0);
+    }
+    return true;
+  }
+  return false;
+}
+
+bool parsePing(const String& line) {
+  if (line == "PING") {
+    sendReply("PONG");
+    return true;
+  }
+  return false;
+}
+
+void processLine(const String& line) {
+  if (parseSet(line)) return;
+  if (parseSpeed(line)) return;
+  if (parseAccel(line)) return;
+  if (parseEnable(line)) return;
+  if (parseZero(line)) return;
+  if (parseHome(line)) return;
+  if (parseSweep(line)) return;
+  if (parsePosQuery(line)) return;
+  if (parsePing(line)) return;
+
+  sendReply("ERR BAD_CMD");
+}
+
+void readCommands() {
+  while (CMD_PORT.available()) {
+    char c = (char)CMD_PORT.read();
+
+    if (c == '\n') {
+      rxLine.trim();
+      if (rxLine.length() > 0) {
+        processLine(rxLine);
+      }
+      rxLine = "";
+    } else if (c != '\r') {
+      rxLine += c;
+      if (rxLine.length() > 120) {
+        rxLine = "";
+      }
+    }
+  }
+}
+
+void setup() {
+  DEBUG_PORT.begin(115200);
+  DEBUG_PORT.println("Gauge controller booting");
+
+  for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    pinMode(gaugePins[i].dirPin, OUTPUT);
+    pinMode(gaugePins[i].stepPin, OUTPUT);
+
+    digitalWrite(gaugePins[i].dirPin, LOW);
+    digitalWrite(gaugePins[i].stepPin, gaugePins[i].stepActiveHigh ? LOW : HIGH);
+
+    if (gaugePins[i].enablePin >= 0) {
+      pinMode(gaugePins[i].enablePin, OUTPUT);
+      setEnable(i, true);
+    }
+
+    gauges[i].lastUpdateMicros = micros();
+  }
+
+  requestHomeAll();
+
+  DEBUG_PORT.println("READY");
+  sendReply("READY");
+}
+
+void loop() {
+  readCommands();
+
+  for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    updateGauge(i);
+  }
+}
\ No newline at end of file