From d0088522b843dfb70827b471a1bdb1603f3e5e34 Mon Sep 17 00:00:00 2001
From: Gordon Williams <gw@pur3.co.uk>
Date: Fri, 18 Sep 2020 11:51:17 +0100
Subject: [PATCH] more GPS functionality added

---
 testing/GPS-comms.js | 77 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 65 insertions(+), 12 deletions(-)

diff --git a/testing/GPS-comms.js b/testing/GPS-comms.js
index 67df178f8..b9c2c645c 100644
--- a/testing/GPS-comms.js
+++ b/testing/GPS-comms.js
@@ -1,22 +1,13 @@
-/* This code allows you to communicate with the GPS
-receiver in Bangle.js in order to set it up.
-
-Protocol spec:
-
-https://cdn.sparkfun.com/assets/0/b/0/f/7/u-blox8-M8_ReceiverDescrProtSpec__UBX-13003221__Public.pdf
-
-*/
-
 Bangle.setGPSPower(1)
 //Bangle.on('GPS',print);
 
-Bangle.on('GPS-raw',function (d) {
+/*Bangle.on('GPS-raw',function (d) {
   if (d[0]=="$") return;
   if (d.startsWith("\xB5\x62\x05\x01")) print("GPS ACK");
   else if (d.startsWith("\xB5\x62\x05\x00")) print("GPS NACK");
   // 181,98 sync chars  
   else print("GPS",E.toUint8Array(d).join(","));
-});
+});*/
 function writeGPScmd(cmd) {
   var d = [0xB5,0x62]; // sync chars
   d = d.concat(cmd);
@@ -28,6 +19,23 @@ function writeGPScmd(cmd) {
   d.push(a,b);
   Serial1.write(d);
 }
+function readGPScmd(cmd, callback) {
+  var prefix = String.fromCharCode(0xb5,0x62,cmd[0],cmd[1]);
+  function handler(d) {
+    if (!d.startsWith(prefix)) return;
+    clearInterval(timeout);
+    var a = E.toUint8Array(d);
+    // cut off id + length 
+    a = new Uint8Array(a.buffer,6, a.length-8);
+    callback(a);
+  }
+  Bangle.on('GPS-raw',handler);
+  var timeout = setTimeout(function() {
+    callback();
+    Bangle.removeListener('GPS-raw',handler);
+  }, 2000);
+  writeGPScmd(cmd);
+}
 function UBX_CFG_PMS() {
   // UBX-CFG-PMS - enable power management - Super-E
   writeGPScmd([0x06,0x86, // msg class + type
@@ -64,4 +72,49 @@ function UBX_CFG_MSG(msg,enable) {
 // Enter super-e low power
 // UBX_CFG_PMS()
 // Disable DTM messages (see UBX_CFG_MSG comments):
-UBX_CFG_MSG("DTM",false);
\ No newline at end of file
+//UBX_CFG_MSG("DTM",false);
+// UBX-CFG-HNR (0x06 0x5C) - high rate (up to 30hz)
+
+
+// GPS 181,98,6,62,60,0,0,32,32,7,0,8,16,0,1,0,1,1,1,1,3,0,0,0,1,1,2,4,8,0,0,0,1,1,3,8,16,0,1,0,1,1,4,0,8,0,0,0,1,3,5,0,3,0,1,0,1,5,6,8,14,0,0,0,1,1,84,27
+//GPS ACK
+
+function getUBX_CFG_GNSS() {
+  // 
+  readGPScmd([0x06,0x3E,0,0], function(a) {
+    print("CFG_GNSS",a.join(","), a.length);
+    var info = {
+      numTrkChHw : a[1],
+      numTrkChUse : a[2],
+      configs : []
+    };
+    for (var i=4;i<a.length;i+=8) {
+      info.configs.push({
+        gnss : ["GPS","SBAS","Galileo","BeiDou","IMES","QZSS","GLONASS"][a[i+0]],
+        reservedCh : a[1+1],
+        maxCh : a[i+2],
+        enabled : a[i+4]&1,
+        sigCfgMask : a[i+6],
+        flags : [a[i+4],a[i+5],a[i+6],a[i+7]]
+      });
+    }
+    print(info);
+  });
+}
+
+function getUBX_CFG_NMEA() {
+  readGPScmd([0x06,0x17,0,0], function(a) {
+    print("CFG_NMEA",a.join(","), a.length);
+    var info = {
+      filter : a[0],
+      nmeaVersion : {0x4b:4.11,0x41:4.1,0x40:4,0x23:2.3,0x21:2.1}[a[1]],
+      flags : a[3]
+    };
+    print(info);
+  });
+}
+
+getUBX_CFG_NMEA();
+
+// UBX-MGA-INI-TIME_UTC looks promising for a start time
+