diff --git a/apps/skyspy/ChangeLog b/apps/skyspy/ChangeLog
index 15a83ceeb..66c161509 100644
--- a/apps/skyspy/ChangeLog
+++ b/apps/skyspy/ChangeLog
@@ -1,3 +1,4 @@
 0.01: attempt to import
 0.02: Minor code improvements
 0.03: big rewrite, adding time-adjust and altitude-adjust functionality
+0.04: more refactoring, fix lat/lon display
diff --git a/apps/skyspy/metadata.json b/apps/skyspy/metadata.json
index d8e9d1356..fdd63ec70 100644
--- a/apps/skyspy/metadata.json
+++ b/apps/skyspy/metadata.json
@@ -1,6 +1,6 @@
 { "id": "skyspy",
   "name": "Sky Spy",
-  "version": "0.03",
+  "version": "0.04",
   "description": "Application for debugging GPS problems",
   "icon": "app.png",
   "readme": "README.md",
diff --git a/apps/skyspy/skyspy.app.js b/apps/skyspy/skyspy.app.js
index a3a0d8776..16e18a481 100644
--- a/apps/skyspy/skyspy.app.js
+++ b/apps/skyspy/skyspy.app.js
@@ -1,426 +1,493 @@
 /* Sky spy */
 
-/* fmt library v0.1 */
+/* fmt library v0.2.3 */
 let fmt = {
-    icon_alt : "\0\x08\x1a\1\x00\x00\x00\x20\x30\x78\x7C\xFE\xFF\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
-    icon_m : "\0\x08\x1a\1\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
-    icon_km : "\0\x08\x1a\1\xC3\xC6\xCC\xD8\xF0\xD8\xCC\xC6\xC3\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
-    icon_kph : "\0\x08\x1a\1\xC3\xC6\xCC\xD8\xF0\xD8\xCC\xC6\xC3\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\xFF\x00\xC3\xC3\xFF\xC3\xC3",
-    icon_c : "\0\x08\x1a\1\x00\x00\x60\x90\x90\x60\x00\x7F\xFF\xC0\xC0\xC0\xC0\xC0\xFF\x7F\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_alt : "\0\x08\x1a\1\x00\x00\x00\x20\x30\x78\x7C\xFE\xFF\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_m : "\0\x08\x1a\1\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_km : "\0\x08\x1a\1\xC3\xC6\xCC\xD8\xF0\xD8\xCC\xC6\xC3\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_kph : "\0\x08\x1a\1\xC3\xC6\xCC\xD8\xF0\xD8\xCC\xC6\xC3\x00\xC3\xE7\xFF\xDB\xC3\xC3\xC3\xC3\x00\xFF\x00\xC3\xC3\xFF\xC3\xC3",
+  icon_c : "\0\x08\x1a\1\x00\x00\x60\x90\x90\x60\x00\x7F\xFF\xC0\xC0\xC0\xC0\xC0\xFF\x7F\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_hpa : "\x00\x08\x16\x01\x00\x80\xb0\xc8\x88\x88\x88\x00\xf0\x88\x84\x84\x88\xf0\x80\x8c\x92\x22\x25\x19\x00\x00",
+  icon_9 : "\x00\x08\x16\x01\x00\x00\x00\x00\x38\x44\x44\x4c\x34\x04\x04\x38\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+  icon_10 : "\x00\x08\x16\x01\x00\x08\x18\x28\x08\x08\x08\x00\x00\x18\x24\x24\x24\x24\x18\x00\x00\x00\x00\x00\x00\x00",
 
   /* 0 .. DD.ddddd
      1 .. DD MM.mmm'
      2 .. DD MM'ss"
-   */
-    geo_mode : 1,
-    
-    init: function() {},
-    fmtDist: function(km) { return km.toFixed(1) + this.icon_km; },
-    fmtSteps: function(n) { return this.fmtDist(0.001 * 0.719 * n); },
-    fmtAlt: function(m) { return m.toFixed(0) + this.icon_alt; },
-    fmtTimeDiff: function(d) {
-        if (d < 180)
-            return ""+d.toFixed(0);
-        d = d/60;
-        return ""+d.toFixed(0)+"m";
-    },
-    fmtAngle: function(x) {
-        switch (this.geo_mode) {
-        case 0:
-            return "" + x;
-        case 1: {
-            let d = Math.floor(x);
-            let m = x - d;
-            m = m*60;
-            return "" + d + " " + m.toFixed(3) + "'";
-        }
-        case 2: {
-            let d = Math.floor(x);
-            let m = x - d;
-            m = m*60;
-            let mf = Math.floor(m);
-            let s = m - mf;
-            s = s*60;
-            return "" + d + " " + mf + "'" + s.toFixed(0) + '"';
-        }
-        }
-        return "bad mode?";
-    },
-    fmtPos: function(pos) {
-        let x = pos.lat;
-        let c = "N";
-        if (x<0) {
-            c = "S";
-            x = -x;
-        }
-        let s = c+this.fmtAngle(pos.lat) + "\n";
-        c = "E";
-        if (x<0) {
-            c = "W";
-            x = -x;
-        }
-        return s + c + this.fmtAngle(pos.lon);
-    },
+  */
+  geo_mode : 1,
+
+  init: function() {},
+  fmtDist: function(km) {
+    if (km >= 1.0) return km.toFixed(1) + this.icon_km;
+    return (km*1000).toFixed(0) + this.icon_m;
+  },
+  fmtSteps: function(n) { return this.fmtDist(0.001 * 0.719 * n); },
+  fmtAlt: function(m) { return m.toFixed(0) + this.icon_alt; },
+  fmtTemp: function(c) { return c.toFixed(1) + this.icon_c; },
+  fmtPress: function(p) {
+    if (p < 900 || p > 1100)
+      return p.toFixed(0) + this.icon_hpa;
+    if (p < 1000) {
+      p -= 900;
+      return this.icon_9 + this.add0(p.toFixed(0)) + this.icon_hpa;
+    }
+    p -= 1000;
+    return this.icon_10 + this.add0(p.toFixed(0)) + this.icon_hpa;
+  },
+  draw_dot : 1,
+  add0: function(i) {
+    if (i > 9) {
+      return ""+i;
+    } else {
+      return "0"+i;
+    }
+  },
+  fmtTOD: function(now) {
+    this.draw_dot = !this.draw_dot;
+    let dot = ":";
+    if (!this.draw_dot)
+      dot = ".";
+    return now.getHours() + dot + this.add0(now.getMinutes());
+  },
+  fmtNow: function() { return this.fmtTOD(new Date()); },
+  fmtTimeDiff: function(d) {
+    if (d < 180)
+      return ""+d.toFixed(0);
+    d = d/60;
+    return ""+d.toFixed(0)+"m";
+  },
+  fmtAngle: function(x) {
+    switch (this.geo_mode) {
+    case 0:
+      return "" + x;
+    case 1: {
+      let d = Math.floor(x);
+      let m = x - d;
+      m = m*60;
+      return "" + d + " " + m.toFixed(3) + "'";
+    }
+    case 2: {
+      let d = Math.floor(x);
+      let m = x - d;
+      m = m*60;
+      let mf = Math.floor(m);
+      let s = m - mf;
+      s = s*60;
+      return "" + d + " " + mf + "'" + s.toFixed(0) + '"';
+    }
+    }
+    return "bad mode?";
+  },
+  fmtPos: function(pos) {
+    let x = pos.lat;
+    let c = "N";
+    if (x<0) {
+      c = "S";
+      x = -x;
+    }
+    let s = c+this.fmtAngle(x) + "\n";
+    x = pos.lon;
+    c = "E";
+    if (x<0) {
+      c = "W";
+      x = -x;
+    }
+    return s + c + this.fmtAngle(x);
+  },
+  fmtFix: function(fix, t) {
+    if (fix && fix.fix && fix.lat) {
+      return this.fmtSpeed(fix.speed) + " " +
+        this.fmtAlt(fix.alt);
+    } else {
+      return "N/FIX " + this.fmtTimeDiff(t);
+    }
+  },
+  fmtSpeed: function(kph) {
+    return kph.toFixed(1) + this.icon_kph;
+  },
+  radians: function(a) { return a*Math.PI/180; },
+  degrees: function(a) { return a*180/Math.PI; },
+  // distance between 2 lat and lons, in meters, Mean Earth Radius = 6371km
+  // https://www.movable-type.co.uk/scripts/latlong.html
+  // (Equirectangular approximation)
+  // returns value in meters
+  distance: function(a,b) {
+    var x = this.radians(b.lon-a.lon) * Math.cos(this.radians((a.lat+b.lat)/2));
+    var y = this.radians(b.lat-a.lat);
+    return Math.sqrt(x*x + y*y) * 6371000;
+  },
+  // thanks to waypointer
+  bearing: function(a,b) {
+    var delta = this.radians(b.lon-a.lon);
+    var alat = this.radians(a.lat);
+    var blat = this.radians(b.lat);
+    var y = Math.sin(delta) * Math.cos(blat);
+    var x = Math.cos(alat) * Math.sin(blat) -
+        Math.sin(alat)*Math.cos(blat)*Math.cos(delta);
+    return Math.round(this.degrees(Math.atan2(y, x)));
+  },
 };
 
-/* gps library v0.1 */
+/* gps library v0.1.4 */
 let gps = {
-    emulator: -1,
-    init: function(x) {
-        this.emulator = (process.env.BOARD=="EMSCRIPTEN" 
-                         || process.env.BOARD=="EMSCRIPTEN2")?1:0;
-    },
-    state: {},
-    on_gps: function(f) {
-        let fix = this.getGPSFix();
-        f(fix);
+  emulator: -1,
+  init: function(x) {
+    this.emulator = (process.env.BOARD=="EMSCRIPTEN" 
+                     || process.env.BOARD=="EMSCRIPTEN2")?1:0;
+  },
+  state: {},
+  on_gps: function(f) {
+    let fix = this.getGPSFix();
+    f(fix);
 
-        /*
-          "lat": number,      // Latitude in degrees
-          "lon": number,      // Longitude in degrees
-          "alt": number,      // altitude in M
-          "speed": number,    // Speed in kph
-          "course": number,   // Course in degrees
-          "time": Date,       // Current Time (or undefined if not known)
-          "satellites": 7,    // Number of satellites
-          "fix": 1            // NMEA Fix state - 0 is no fix
-          "hdop": number,     // Horizontal Dilution of Precision
-        */
-        this.state.timeout = setTimeout(this.on_gps, 1000, f);
-    },
-    off_gps: function() {
-        clearTimeout(this.state.timeout);
-    },
-    getGPSFix: function() {
-        if (!this.emulator)
-            return Bangle.getGPSFix();
-        let fix = {};
-        fix.fix = 1;
-        fix.lat = 50;
-        fix.lon = 14;
-        fix.alt = 200;
-        fix.speed = 5;
-        fix.course = 30;
-        fix.time = Date();
-        fix.satellites = 5;
-        fix.hdop = 12;
-        return fix;
-    }
+    /*
+      "lat": number,      // Latitude in degrees
+      "lon": number,      // Longitude in degrees
+      "alt": number,      // altitude in M
+      "speed": number,    // Speed in kph
+      "course": number,   // Course in degrees
+      "time": Date,       // Current Time (or undefined if not known)
+      "satellites": 7,    // Number of satellites
+      "fix": 1            // NMEA Fix state - 0 is no fix
+      "hdop": number,     // Horizontal Dilution of Precision
+    */
+    this.state.timeout = setTimeout(this.on_gps, 1000, f);
+  },
+  off_gps: function() {
+    clearTimeout(this.state.timeout);
+  },
+  getGPSFix: function() {
+    if (!this.emulator)
+      return Bangle.getGPSFix();
+    let fix = {};
+    fix.fix = 1;
+    fix.lat = 50;
+    fix.lon = 14-(getTime()-this.gps_start) / 1000; /* Go West! */
+    fix.alt = 200;
+    fix.speed = 5;
+    fix.course = 30;
+    fix.time = Date();
+    fix.satellites = 5;
+    fix.hdop = 12;
+    return fix;
+  },
+  gps_start : -1,
+  start_gps: function() {
+    Bangle.setGPSPower(1, "libgps");
+    this.gps_start = getTime();
+  },
+  stop_gps: function() {
+    Bangle.setGPSPower(0, "libgps");
+  },
 };
 
-var display = 0;
-var debug = 0;
-var gps_start;
-var cur_altitude;
-var wi = 24;
-var h = 176-wi, w = 176;
-var fix;
-var adj_time = 0, adj_alt = 0;
-
-function radA(p) { return p*(Math.PI*2); }
-function radD(d) { return d*(h/2); }
-function radX(p, d) {
-  let a = radA(p);
-  return w/2 + Math.sin(a)*radD(d);
-}
-function radY(p, d) {
-  let a = radA(p);
-  return h/2 - Math.cos(a)*radD(d) + wi;
-}
-
-var qalt = -1, min_dalt, max_dalt, step;
-function resetAlt() {
-  min_dalt = 9999; max_dalt = -9999; step = 0;
-}
-resetAlt();
-
-function calcAlt(alt, cur_altitude) {
-    let dalt = alt - cur_altitude;
-
-    if (min_dalt > dalt)
-      min_dalt = dalt;
-    if (max_dalt < dalt)
-      max_dalt = dalt;
-
-    let ddalt = max_dalt - min_dalt;
-    return ddalt;
-}
-function updateGps() {
-  let lat = "lat ", alt = "?",
-      speed = "speed ", hdop = "?", adelta = "adelta ",
-      tdelta = "tdelta ";
-
-  fix = gps.getGPSFix();
-  if (adj_time) {
-    print("Adjusting time");
-    setTime(fix.time.getTime()/1000);
-    adj_time = 0;
-  }
-  if (adj_alt) {
-      print("Adjust altitude");
-      if (qalt < 5) {
-          let rest_altitude = fix.alt;
-          let alt_adjust = cur_altitude - rest_altitude;
-          let abs = Math.abs(alt_adjust);
-          print("adj", alt_adjust);
-          let o = Bangle.getOptions();
-          if (abs > 10 && abs < 150) {
-              let a = 0.01;
-              // FIXME: draw is called often compared to alt reading
-              if (cur_altitude > rest_altitude)
-                  a = -a;
-              o.seaLevelPressure = o.seaLevelPressure + a;
-              Bangle.setOptions(o);
-          }
-          msg = o.seaLevelPressure.toFixed(1) + "hPa";
-          print(msg);
-      }
-  }
-
-  try {
-    Bangle.getPressure().then((x) => {
-      cur_altitude = x.altitude;
-    }, print);
-  } catch (e) {
-    //print("Altimeter error", e);
-  }
-
-
-  //print(fix);
-  if (fix && fix.time) {
-    tdelta = "" + (getTime() - fix.time.getTime()/1000).toFixed(0);
-  }
-  if (fix && fix.fix && fix.lat) {
-    lat = "" + fmt.fmtPos(fix);
-    alt = "" + fix.alt.toFixed(0);
-    adelta = "" + (cur_altitude - fix.alt).toFixed(0);
-    speed = "" + fix.speed.toFixed(1);
-    hdop = "" + fix.hdop.toFixed(0);
-  } else {
-    lat = "NO FIX\n"
-       + "" + (getTime() - gps_start).toFixed(0) + "s " 
-          + sats_used + "/" + snum;
-    if (cur_altitude)
-      adelta = "" + cur_altitude.toFixed(0);
-  }
-
-  let ddalt = calcAlt(alt, cur_altitude);
-  let msg = "";
-  if (display == 1) {
-    msg = lat +
-         "\ne" + hdop + "m "+tdelta+"s\n" + 
-         speed + "km/h\n"+ alt + "m+" + adelta + "\nmsghere";
-  }
-  if (display == 2) {
-    /* qalt is altitude quality estimate -- over ten seconds,
-       computes differences between GPS and barometric altitude.
-       The lower the better.
-       
-       ddalt is just a debugging -- same estimate, but without
-       waiting 10 seconds, so will be always optimistic at start
-       of the cycle */
-    msg = speed + "km/h\n" +
-      "e"+hdop + "m"
-      +"\ndd "+qalt.toFixed(0) + "\n(" + step + "/" + ddalt.toFixed(0) + ")" +
-      "\n"+alt + "m+" + adelta;
-  }
-    step++;
-    if (step == 10) {
-      qalt = max_dalt - min_dalt;
-      resetAlt();
-    }
-  if (display > 0) {
-    g.reset().setFont("Vector", 31)
-    .setColor(1,1,1)
-    .fillRect(0, wi, 176, 176)
-    .setColor(0,0,0)
-    .drawString(msg, 3, 25);
-  }
-  if (debug > 0)
-    print(fix);
-  setTimeout(updateGps, 1000);
-}
-
-function radLine(a1, d1, a2, d2) {
-  g.drawLine(radX(a1, d1), radY(a1, d1), radX(a2, d2), radY(a2, d2));
-}
-function radCircle(d) {
-  let step = 0.05;
-  for (let i=0; i<1; i+=0.05) {
-    radLine(i-step, d, i, d);
-  }
-  //g.flip();
-}
-function drawGrid() {
-  g.setColor(0,0,0);
-  radLine(0, 1, 0.5, 1);
-  radLine(0.25, 1, 0.75, 1);
-  radCircle(0.5);
-  radCircle(1.0);
-}
-function drawSat(s) {
-  let a = s.azi / 360;
-  let e = ((90 - s.ele) / 90);
-  let x = radX(a, e);
-  let y = radY(a, e);
-
-  if (s.snr == "")
-    g.setColor(1, 0.25, 0.25);
-  else {
-    //let snr = 1*s.snr;
-    g.setColor(0, 0, 0);
-    //sats_receiving ++;
-  }
-  g.drawString(s.id, x, y);
-
-}
-
-// Should correspond to view from below.
-// https://in-the-sky.org//satmap_radar.php?year=2023&month=10&day=24&skin=1
-function drawSats(sats) {
-  //sats_receiving = 0;
-  g.reset().setFont("Vector", 20)
-    .setColor(1,1,1)
-    .fillRect(0, 30, 176, 176);
-
-  drawGrid();
-  for (var s of sats) {
-    if (debug > 1)
-      print(s.ele, s.azi, s.snr);
-    drawSat(s);
-  }
-  if (fix && fix.fix && fix.lat) {
-    g.setColor(0, 0, 0);
-    g.drawString(fix.satellites + "/" + fix.hdop, 10, 150);
-  }
-}
-
-var sats = [];
-var snum = 0;
-var sats_used = 0;
-
-function parseRaw(msg, lost) {
-  if (lost)
-    print("## data lost");
-  let s = msg.split(",");
-  if (s[0] != "$GPGSV")
-    return;
-  //print("Message", s[2], s[1]);
-  if (debug > 0)
-    print(msg);
-
-  if (s[2] == "1") {
-    snum = 0;
-    sats = [];
-    sats_used = 0;
-  }
-
-  let view = 1 * s[3];
-
-  // s[3] -- sats in view.
-  // id, ele, azi, snr
-  if (debug > 0)
-    print("in view:", view);
-  let i = 4;
-  let k = 4;
-  if (view - snum < k)
-    k = view - snum;
-  for (let j=0; j<k; j++) {
-    let sat = {};
-    sat.id = s[i++];
-    sat.ele = 1*s[i++];
-    sat.azi = 1*s[i++];
-    sat.snr = s[i++];
-    if (sat.snr != "")
-      sats_used++;
-    if (debug > 0)
-      print("  ", sat);
-    sats[snum++] = sat;
-  }
-  if (debug > 1)
-    print("Checksum:", s[i]);
-  if (s[1] == s[2]) {
-    print("Complete...");
-    //print(sats);
-    if (display == 0)
-      drawSats(sats);
-  }
-}
-
-function markGps() {
-  Bangle.setGPSPower(1, "skyspy");
-  Bangle.on('GPS-raw', parseRaw);
-  gps_start = getTime();
-  updateGps();
-}
-function drawMsg(msg) {
-  g.reset().setFont("Vector", 35)
-    .setColor(1,1,1)
-    .fillRect(0, wi, 176, 176)
-    .setColor(0,0,0)
-    .drawString(msg, 5, 30);
-}
-function drawBusy() {
-  drawMsg("\n.oO busy");
-}
-
-var numScreens = 3;
-
-function nextScreen() {
-    display = display + 1;
-    if (display == numScreens)
-        display = 0;
-    drawBusy();
-}
-
-function prevScreen() {
-    display = display - 1;
-    if (display < 0)
-        display = numScreens - 1;
-    drawBusy();
-}
-
-function onSwipe(dir) {
-    nextScreen();
-}
-
-var last_b = 0;
-function touchHandler(d) {
+/* ui library 0.1.3 */
+let ui = {
+  display: 0,
+  numScreens: 2,
+  drawMsg: function(msg) {
+    g.reset().setFont("Vector", 35)
+      .setColor(1, 1, 1)
+      .fillRect(0, this.wi, this.w, this.y2)
+      .setColor(0, 0, 0)
+      .drawString(msg, 5, 30)
+      .flip();
+  },
+  drawBusy: function() {
+    this.drawMsg("\n.oO busy");
+  },
+  nextScreen: function() {
+    print("nextS");
+    this.display = this.display + 1;
+    if (this.display == this.numScreens)
+      this.display = 0;
+    this.drawBusy();
+  },
+  prevScreen: function() {
+    print("prevS");
+    this.display = this.display - 1;
+    if (this.display < 0)
+      this.display = this.numScreens - 1;
+    this.drawBusy();
+  },
+  onSwipe: function(dir) {
+    this.nextScreen();
+  },
+  wi: 24,
+  y2: 176,
+  h: 152,
+  w: 176,
+  last_b: 0,
+  topLeft: function() { this.drawMsg("Unimpl"); },
+  topRight: function() { this.drawMsg("Unimpl"); },
+  touchHandler: function(d) {
     let x = Math.floor(d.x);
     let y = Math.floor(d.y);
     
-    if (d.b != 1 || last_b != 0) {
-        last_b = d.b;
-        return;
+    if (d.b != 1 || this.last_b != 0) {
+      this.last_b = d.b;
+      return;
     }
-    last_b = d.b;
+    
+    print("touch", x, y, this.h, this.w);
 
-    if ((x<h/2) && (y<w/2)) {
-        drawMsg("Clock\nadjust");
-        adj_time = 1;
+    if ((x<this.w/2) && (y<this.y2/2))
+      this.topLeft();
+    if ((x>this.w/2) && (y<this.y2/2))
+      this.topRight();
+    if ((x<this.w/2) && (y>this.y2/2)) {
+      print("prev");
+      this.prevScreen();
     }
-    if ((x>h/2) && (y<w/2)) {
-        drawMsg("Alt\nadjust");
-        adj_alt = 1;
+    if ((x>this.w/2) && (y>this.y2/2)) {
+      print("next");
+      this.nextScreen();
     }
+  },
+  init: function() {
+    this.h = this.y2 - this.wi;
+    this.drawBusy();
+  }
+};
 
-    if ((x<h/2) && (y>w/2))
-        prevScreen();
-    if ((x>h/2) && (y>w/2))
-        nextScreen();
+
+var debug = 0;
+var cur_altitude;
+var fix;
+var adj_time = 0, adj_alt = 0;
+
+/* radial angle -- convert 0..1 to 0..2pi */
+function radA(p) { return p*(Math.PI*2); }
+/* radial distance -- convert 0..1 to something that fits on screen */
+function radD(d) { return d*(ui.h/2); }
+/* given angle/distance, get X coordinate */
+function radX(p, d) {
+  let a = radA(p);
+  return ui.w/2 + Math.sin(a)*radD(d);
+}
+/* given angle/distance, get Y coordinate */
+function radY(p, d) {
+  let a = radA(p);
+  return ui.h/2 - Math.cos(a)*radD(d) + ui.wi;
 }
 
+let gps_quality = {
+  min_dalt: 9999,
+  max_dalt: -9999,
+  step: 0,
+
+  resetAlt: function() {
+    this.min_dalt = 9999;
+    this.max_dalt = -9999;
+    this.step = 0;
+  },
+
+  calcAlt: function(alt, cur_altitude) {
+    let dalt = alt - cur_altitude;
+    if (this.min_dalt > dalt) this.min_dalt = dalt;
+    if (this.max_dalt < dalt) this.max_dalt = dalt;
+    return this.max_dalt - this.min_dalt;
+  }
+};
+
+var qalt = 9999; /* global, altitude quality */
+
+let gps_display = {
+  updateGps: function() {
+    let lat = "lat ", alt = "?", speed = "speed ", hdop = "?",
+        adelta = "adelta ", tdelta = "tdelta ";
+
+    fix = gps.getGPSFix();
+    if (adj_time) {
+      print("Adjusting time");
+      setTime(fix.time.getTime()/1000);
+      adj_time = 0;
+    }
+    if (adj_alt) {
+      print("Adjust altitude");
+      gps_display.adjustAltitude();
+    }
+
+    gps_display.updateAltitude();
+    gps_display.displayData(lat, alt, speed, hdop, adelta, tdelta);
+
+    setTimeout(gps_display.updateGps, 1000);
+  },
+
+  adjustAltitude: function() {
+    if (qalt < 5) {
+      let rest_altitude = fix.alt;
+      let alt_adjust = cur_altitude - rest_altitude;
+      let abs = Math.abs(alt_adjust);
+      print("adj", alt_adjust);
+      let o = Bangle.getOptions();
+      if (abs > 10 && abs < 150) {
+        let a = 0.01;
+        if (cur_altitude > rest_altitude) a = -a;
+        o.seaLevelPressure = o.seaLevelPressure + a;
+        Bangle.setOptions(o);
+      }
+      print(o.seaLevelPressure.toFixed(1) + "hPa");
+    }
+  },
+
+  updateAltitude: function() {
+    try {
+      Bangle.getPressure().then((x) => {
+        cur_altitude = x.altitude;
+      }, print);
+    } catch (e) {}
+  },
+
+  displayData: function(lat, alt, speed, hdop, adelta, tdelta) {
+    if (fix && fix.time) {
+      tdelta = "" + (getTime() - fix.time.getTime()/1000).toFixed(0);
+    }
+    if (fix && fix.fix && fix.lat) {
+      lat = "" + fmt.fmtPos(fix);
+      alt = "" + fix.alt.toFixed(0);
+      adelta = "" + (cur_altitude - fix.alt).toFixed(0);
+      speed = "" + fix.speed.toFixed(1);
+      hdop = "" + fix.hdop.toFixed(0);
+    } else {
+      lat = "NO FIX\n" + (getTime() - gps.gps_start).toFixed(0) + "s " 
+            + sky.sats_used + "/" + sky.snum;
+      if (cur_altitude) adelta = "" + cur_altitude.toFixed(0);
+    }
+
+    let ddalt = gps_quality.calcAlt(alt, cur_altitude);
+    let msg = this.formatDisplayMessage(lat, alt, speed, hdop, adelta, ddalt, tdelta);
+
+    if (ui.display > 0) {
+      g.reset().setFont("Vector", 31)
+        .setColor(1,1,1).fillRect(0, ui.wi, ui.w, ui.y2)
+        .setColor(0,0,0).drawString(msg, 3, 25);
+    }
+    if (debug > 0) print(fix);
+  },
+
+  formatDisplayMessage: function(lat, alt, speed, hdop, adelta, ddalt, tdelta) {
+    let msg = "";
+    if (ui.display == 1) {
+      msg = lat + "\ne" + hdop + "m " + tdelta + "s\n" + 
+            speed + "km/h\n" + alt + "m+" + adelta + "\nmsghere";
+    } else if (ui.display == 2) {
+      msg = speed + "km/h\n" + "e" + hdop + "m" + "\ndd " +
+            qalt.toFixed(0) + "\n(" + gps_quality.step + "/" + 
+            ddalt.toFixed(0) + ")" + "\n" + alt + "m+" + adelta;
+    }
+    gps_quality.step++;
+    if (gps_quality.step == 10) {
+      qalt = gps_quality.max_dalt - gps_quality.min_dalt;
+      gps_quality.resetAlt();
+    }
+    return msg;
+  }
+};
+
+/* sky library v0.0.1 */
+let sky = {
+  sats: [],
+  snum: 0,
+  sats_used: 0,
+
+  drawGrid: function() {
+    g.setColor(0,0,0);
+    this.radLine(0, 1, 0.5, 1);
+    this.radLine(0.25, 1, 0.75, 1);
+    this.radCircle(0.5);
+    this.radCircle(1.0);
+  },
+
+  radLine: function(a1, d1, a2, d2) {
+    g.drawLine(radX(a1, d1), radY(a1, d1), radX(a2, d2), radY(a2, d2));
+  },
+
+  radCircle: function(d) {
+    /* FIXME: .. should do real circle */
+    g.drawCircle(radX(0, 0), radY(0, 0), radD(d));
+    if (1)
+      return;
+    let step = 0.05;
+    for (let i = 0; i < 1; i += 0.05) {
+      this.radLine(i - step, d, i, d);
+    }
+  },
+
+  drawSat: function(s) {
+    let a = s.azi / 360;
+    let e = ((90 - s.ele) / 90);
+    let x = radX(a, e);
+    let y = radY(a, e);
+
+    g.setColor(s.snr === "" ? 1 : 0, s.snr === "" ? 0.25 : 0, s.snr === "" ? 0.25 : 0);
+    g.drawString(s.id, x, y);
+  },
+
+  // Should correspond to view from below.
+  // https://in-the-sky.org//satmap_radar.php?year=2023&month=10&day=24&skin=1
+  drawSats: function(sats) {
+    g.reset()
+      .setColor(1, 1, 1)
+      .fillRect(0, ui.wi, ui.w, ui.y2)
+      .setFont("Vector", 20)
+      .setFontAlign(0, 0);
+    this.drawGrid();
+    sats.forEach(s => this.drawSat(s));
+
+    if (fix && fix.fix && fix.lat) {
+      g.setColor(0, 0, 0)
+       .setFontAlign(-1, 1);
+      g.drawString(fix.satellites + "/" + fix.hdop, 5, ui.y2);
+    }
+  },
+  parseRaw: function(msg, lost) {
+    if (ui.display != 0)
+      return;
+    if (lost) print("## data lost");
+    let s = msg.split(",");
+    if (s[0] !== "$GPGSV") return;
+
+    if (s[2] === "1") {
+      this.snum = 0;
+      this.sats = [];
+      this.sats_used = 0;
+    }
+
+    let view = 1 * s[3];
+    let k = Math.min(4, view - this.snum);
+    for (let i = 4, j = 0; j < k; j++) {
+      let sat = { id: s[i++], ele: 1 * s[i++], azi: 1 * s[i++], snr: s[i++] };
+      if (sat.snr !== "") this.sats_used++;
+      this.sats[this.snum++] = sat;
+    }
+
+    if (s[1] === s[2]) sky.drawSats(this.sats);
+  }
+};
+
+function markGps() {
+  gps.start_gps();
+  Bangle.on('GPS-raw', sky.parseRaw);
+  gps_display.updateGps();
+}
+
+ui.init();
+ui.numScreens = 3;
 gps.init();
+gps_quality.resetAlt();
 fmt.init();
 
-Bangle.on("drag", touchHandler);
+ui.topLeft = () => { ui.drawMsg("Clock\nadjust"); adj_time = 1; };
+ui.topRight = () => { ui.drawMsg("Alt\nadjust"); adj_alt = 1; };
+
+Bangle.on("drag", (b) => ui.touchHandler(b));
 Bangle.setUI({
   mode : "custom",
-  swipe : onSwipe,
   clock : 0
 });
 
 Bangle.loadWidgets();
 Bangle.drawWidgets();
-drawBusy();
 markGps();