Fix for uploading Nexus meter on Tahoe

lib/drivers/glucorx/glucoRxDriver.js

@@ -108,6 +108,7 @@ const MODELS = {
 };
 
 const READ_TIMEOUT = 2000; // in milliseconds
+const MAX_IDLE_READS = 2; // consecutive read timeouts before giving up on a packet
 const KETONE_VALUE_FACTOR = 10;
 const KETONE_HI = 8.0;
 
@@ -189,58 +190,48 @@ class GlucoRx {
     return response;
   }
 
-  async commandResponse(cmd, payload) {
-    let message = '';
-
-    await this.hidDevice.sendPromisified(this.buildPacket(cmd, payload));
-    debug('Sent command.');
-
+  /**
+   * The CP2110 hands us UART bytes in HID reports of varying size, so a single
+   * packet can arrive in one report or spread over several (macOS 26 delivers
+   * them one byte at a time). Reassemble the stream until we have a full packet,
+   * discarding anything that precedes the start byte.
+   */
+  async readPacket() {
     let raw = [];
-    let result;
-    let foundStart = false;
-    let foundEnd = false;
-    let packetSize = 64;
-    do {
-      result = [];
+    let idleReads = 0;
+
+    while (true) {
       // requests to devices are sequential
       // eslint-disable-next-line no-await-in-loop
-      result = await this.hidDevice.receiveTimeout(READ_TIMEOUT);
-      debug('Incoming bytes:', common.bytes2hex(result));
-
-      if (result.length > 0) {
-        let bytes = null;
-        if (result.length > 1) {
-          if (result.slice(1).every(item => item === 0)) {
-            // only first byte in array is valid
-            bytes = [result[0]];
-          } else {
-            const [ length ] = result;
-            bytes = result.slice(1, length + 1);
-          }
-        } else {
-          bytes = result;
-        }
+      const chunk = await this.hidDevice.receiveTimeout(READ_TIMEOUT);
 
-        if (!foundStart) {
-          if (bytes.includes(CONTROL.START)) {
-            foundStart = true;
-          }
+      if (chunk.length === 0) {
+        idleReads += 1;
+        if (idleReads >= MAX_IDLE_READS) {
+          throw new Error('Timed out waiting for a complete packet.');
         }
+      } else {
+        idleReads = 0;
+        debug('Incoming bytes:', common.bytes2hex(chunk));
+        raw = raw.concat(chunk);
 
-        if (foundStart) {
-          raw = raw.concat(bytes);
+        const start = raw.indexOf(CONTROL.START);
+        if (start > 0) {
+          raw = raw.slice(start);
+        }
 
-          if (raw[raw.length-2] === CONTROL.MD_STOP && raw.length >= PACKET_SIZE) {
-            foundEnd = true;
-          }
+        if (start >= 0 && raw.length >= PACKET_SIZE) {
+          return raw.slice(0, PACKET_SIZE);
         }
       }
-    } while (!foundEnd);
-
-    // Only process if we get data
-    if (raw.length > 0) {
-      message = this.extractPacketIntoMessages(raw);
     }
+  }
+
+  async commandResponse(cmd, payload) {
+    await this.hidDevice.sendPromisified(this.buildPacket(cmd, payload));
+    debug('Sent command.');
+
+    const message = this.extractPacketIntoMessages(await this.readPacket());
 
     if (message === COMMAND.COMM_MODE) {
       // try again
@@ -322,10 +313,17 @@ class GlucoRx {
   async ping() {
     await this.hidDevice.sendPromisified(this.buildPacket(COMMAND.READ_MODEL));
     debug('Sent ping.');
-    const result = await this.hidDevice.receiveTimeout(READ_TIMEOUT);
-    debug('Received:', common.bytes2hex(result));
 
-    if (result.length === 0) {
+    let result = null;
+    try {
+      // consume the whole reply, so that we don't leave part of it behind for
+      // the next command to trip over
+      result = await this.readPacket();
+    } catch (err) {
+      debug('No response to ping:', err.message);
+    }
+
+    if (result == null) {
       if (this.retries <= 3) {
         debug('Retrying..');
         this.retries += 1;
@@ -334,6 +332,7 @@ class GlucoRx {
         throw new Error('Device not responding.');
       }
     } else {
+      debug('Received:', common.bytes2hex(result));
       this.retries = 0;
     }
   }

lib/hidDevice.js

@@ -28,7 +28,9 @@ module.exports = (config) => {
   const packets = [];
 
   function readListener(event) {
-    packets.push(new Uint8Array(event.data.buffer));
+    // event.data is a view of the report payload, without the report ID, and is
+    // not necessarily positioned at the start of its underlying buffer.
+    packets.push(new Uint8Array(event.data.buffer, event.data.byteOffset, event.data.byteLength));
     webHid.dispatchEvent(new Event('data'));
   }
 

locales/en/translation.missing.json

@@ -101,5 +101,8 @@
   "Return to Login": "Return to Login",
   "Turn meter on and check the Bluetooth icon is flashing": "Turn meter on and check the Bluetooth icon is flashing",
   "Please correct the {{device}}'s time or change your Tidepool time zone to match your {{device}} if appropriate and try again.": "Please correct the {{device}}'s time or change your Tidepool time zone to match your {{device}} if appropriate and try again.",
-  "Plug in meter with mini-USB cable": "Plug in meter with mini-USB cable"
+  "Plug in meter with mini-USB cable": "Plug in meter with mini-USB cable",
+  "Plug in meter with": "Plug in meter with",
+  "EZSync002B cable": "EZSync002B cable",
+  "Plug in meter with mini-USB cable. V6 meter not compatible with MacOS.": "Plug in meter with mini-USB cable. V6 meter not compatible with MacOS."
 }