FIX: getChannelData

Author: AJ Keller

changelog.md

@@ -3,6 +3,7 @@
 ### Bug Fixes
 
 * Was missing errors in constants used by ganglion and other ble projects.
+* Fixed getChannelData functions to support 2 channel cytons
 
 # 0.1.4
 

openBCIUtilities.js

@@ -1506,19 +1506,16 @@ function getChannelDataArray (o) {
   if (!Array.isArray(o.channelSettings)) {
     throw new Error('Error [getChannelDataArray]: Channel Settings must be an array!');
   }
-  if (o.hasOwnProperty('protocol')) {
-    if (o.protocol !== k.OBCIProtocolSerial && o.protocol !== k.OBCIProtocolWifi) {
-      throw new Error(`Error [getChannelDataArray]: Invalid protocol must be ${k.OBCIProtocolWifi} or ${k.OBCIProtocolSerial}`);
-    }
-  } else {
+  if (!o.hasOwnProperty('protocol')) {
     o.protocol = k.OBCIProtocolSerial;
   }
   let channelData = [];
   // Grab the sample number from the buffer
   const numChannels = o.channelSettings.length;
   const sampleNumber = o.rawDataPacket[k.OBCIPacketPositionSampleNumber];
   const daisy = numChannels === k.OBCINumberOfChannelsDaisy;
-  const channelsInPacket = numChannels > k.OBCINumberOfChannelsGanglion ? k.OBCINumberOfChannelsDefault : k.OBCINumberOfChannelsGanglion;
+  let channelsInPacket = k.OBCINumberOfChannelsCyton;
+  if (!daisy) channelsInPacket = o.channelSettings.length;
   // Channel data arrays are always 8 long
   for (let i = 0; i < channelsInPacket; i++) {
     if (!o.channelSettings[i].hasOwnProperty('gain')) {
@@ -1548,6 +1545,10 @@ function getChannelDataArray (o) {
       } else {
         scaleFactor = k.OBCIGanglionScaleFactorPerCountVolts;
       }
+    } else if (o.protocol === k.OBCIProtocolBLE) { // For cyton ble not ganglion
+      scaleFactor = ADS1299_VREF / o.channelSettings[i].gain / (Math.pow(2, 23) - 1);
+    } else {
+      throw new Error('Error [getChannelDataArray]: Invalid protocol must be wifi or serial');
     }
 
     // Convert the three byte signed integer and convert it

test/openBCIUtilities-test.js

@@ -535,11 +535,9 @@ describe('openBCIUtilities', function () {
         channelSetting.srb1 = true;
       });
       let data = Buffer.from(k.OBCIRegisterQueryCyton + k.OBCIRegisterQueryAccelerometerFirmwareV1);
-      const majorFirmwareVersion = 1;
       openBCIUtilities.syncChannelSettingsWithRawData({
         channelSettings,
-        data,
-        majorFirmwareVersion
+        data
       });
       expect(channelSettings).to.deep.equal(k.channelSettingsArrayInit(k.OBCINumberOfChannelsCyton));
     });
@@ -699,25 +697,15 @@ describe('openBCIUtilities', function () {
           majorFirmwareVersion
         })).to.throw(k.OBCIErrorUndefinedOrNullInput);
       });
-      it('majorFirmwareVersion is undefined', function () {
-        let channelSettings = k.channelSettingsArrayInit(k.OBCINumberOfChannelsCyton);
-        let data = Buffer.from(k.OBCIRegisterQueryCyton + k.OBCIRegisterQueryCytonDaisy + k.OBCIRegisterQueryAccelerometerFirmwareV3);
-        expect(openBCIUtilities.syncChannelSettingsWithRawData.bind(openBCIUtilities, {
-          channelSettings,
-          data
-        })).to.throw(k.OBCIErrorUndefinedOrNullInput);
-      });
       it('invalid channel settings', function () {
         let channelSettings = [];
         for (let i = 0; i < k.OBCINumberOfChannelsCyton; i++) {
           channelSettings.push({taco: 'gordo'});
         }
-        const majorFirmwareVersion = 3;
         let data = Buffer.from(k.OBCIRegisterQueryCyton + k.OBCIRegisterQueryAccelerometerFirmwareV3);
         expect(openBCIUtilities.syncChannelSettingsWithRawData.bind(openBCIUtilities, {
           channelSettings,
-          data,
-          majorFirmwareVersion
+          data
         })).to.throw(k.OBCIErrorMissingRequiredProperty);
       });
     });
@@ -1768,6 +1756,22 @@ describe('openBCIUtilities', function () {
         }
       });
     });
+    describe('BLE', function () {
+      it('should multiply each channel by the proper scale value', function () {
+        let chanArr = k.channelSettingsArrayInit(k.OBCINumberOfChannelsCytonBLE); // Not in daisy mode
+        let scaleFactor = 4.5 / 24 / (Math.pow(2, 23) - 1);
+        // Call the function under test
+        let valueArray = openBCIUtilities.getChannelDataArray({
+          rawDataPacket: sampleBuf,
+          channelSettings: chanArr,
+          protocol: k.OBCIProtocolBLE
+        });
+        for (let j = 0; j < k.OBCINumberOfChannelsCytonBLE; j++) {
+          // console.log(`channel data ${j + 1}: ${valueArray[j]} : actual ${scaleFactor * (j + 1)}`);
+          expect(valueArray[j]).to.be.closeTo(scaleFactor * (j + 1), 0.0001);
+        }
+      });
+    });
   });
   describe('#countADSPresent', function () {
     it('should not crash on small buff', function () {