diff --git a/src/bme280.js b/src/bme280.js
index d71df90..f007c69 100644
--- a/src/bme280.js
+++ b/src/bme280.js
@@ -3,25 +3,30 @@ import i2c from 'i2c-bus';
 export async function bme(address = 0x76) {
     const i2cBus = await i2c.openPromisified(1);
     const data = await Promise.all([
-        i2cBus.readByte(address, 0xFA),
-        i2cBus.readByte(address, 0xFB),
-        i2cBus.readByte(address, 0xFC),
-        i2cBus.readByte(address, 0xF7),
-        i2cBus.readByte(address, 0xF8),
-        i2cBus.readByte(address, 0xF9),
-        i2cBus.readByte(address, 0xFD),
-        i2cBus.readByte(address, 0xFE),
+        i2cBus.readByte(address, 0xFA), // Temp MSB
+        i2cBus.readByte(address, 0xFB), // Temp LSB
+        i2cBus.readByte(address, 0xFC), // Temp XLSB
+        i2cBus.readByte(address, 0xF7), // Pressure MSB
+        i2cBus.readByte(address, 0xF8), // Pressure LSB
+        i2cBus.readByte(address, 0xF9), // Pressure XLSB
+        i2cBus.readByte(address, 0xFD), // Humidity MSB
+        i2cBus.readByte(address, 0xFE), // Humidity LSB
     ]);
 
-    const T1 = 27504;
-    const T2 = 26435;
-    const T3 = -1000;
+    // Calibration registers
+    const CALIBRATION_LENGTH = 24;
+    const calibBuffer = Buffer.alloc(CALIBRATION_LENGTH);
+    await i2cBus.readI2cBlock(address, 0x88, CALIBRATION_LENGTH, calibBuffer);
+    const T1 = calibBuffer.readUInt16LE(0);
+    const T2 = calibBuffer.readInt16LE(2);
+    const T3 = calibBuffer.readInt16LE(4);
 
     const rawTemp = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
-    let var1 = (((rawTemp >> 3) - (T1 << 1)) * T2) / 2048;
-    let var2 = (((((rawTemp >> 4) - T1) * ((rawTemp >> 4) - T1)) >> 12) * T3) / 16384;
-    let temp = (var1 + var2) / 5120.0;
+    const var1 = (((rawTemp >> 3) - (T1 << 1)) * T2) / 2048;
+    const var2 = (((((rawTemp >> 4) - T1) * ((rawTemp >> 4) - T1)) >> 12) * T3) / 16384;
+    const temp = (var1 + var2) / 5120.0;
 
+    await i2cBus.close();
     return {
         temperature: temp,
         pressure: ((data[3] << 12) | (data[4] << 4) | (data[5] >> 4)) / 25600,
diff --git a/src/bms.js b/src/bms.js
index f44fd53..149ea4a 100644
--- a/src/bms.js
+++ b/src/bms.js
@@ -9,6 +9,7 @@ export async function bms(address = 0x57) {
         i2cBus.readByte(address, 0x23),
         i2cBus.readByte(address, 0x2a),
     ]);
+    await i2cBus.close();
     return {
         charging: !!((data[0] >> 7) & 1),
         percentage: data[4] / 100,