diff --git a/src/modules/SX127x/SX1272.cpp b/src/modules/SX127x/SX1272.cpp
index d3c6bb58..66e95cfa 100644
--- a/src/modules/SX127x/SX1272.cpp
+++ b/src/modules/SX127x/SX1272.cpp
@@ -92,11 +92,11 @@ int16_t SX1272::setBandwidth(float bw) {
   uint8_t newBandwidth;
 
   // check allowed bandwidth values
-  if(abs(bw - 125.0) <= 0.001) {
+  if(fabs(bw - 125.0) <= 0.001) {
     newBandwidth = SX1272_BW_125_00_KHZ;
-  } else if(abs(bw - 250.0) <= 0.001) {
+  } else if(fabs(bw - 250.0) <= 0.001) {
     newBandwidth = SX1272_BW_250_00_KHZ;
-  } else if(abs(bw - 500.0) <= 0.001) {
+  } else if(fabs(bw - 500.0) <= 0.001) {
     newBandwidth = SX1272_BW_500_00_KHZ;
   } else {
     return(ERR_INVALID_BANDWIDTH);
diff --git a/src/modules/SX127x/SX1276.cpp b/src/modules/SX127x/SX1276.cpp
index 1877862b..e97d7ef9 100644
--- a/src/modules/SX127x/SX1276.cpp
+++ b/src/modules/SX127x/SX1276.cpp
@@ -57,7 +57,7 @@ int16_t SX1276::setFrequency(float freq) {
   if(getActiveModem() == SX127X_LORA) {
     // sensitivity optimization for 500kHz bandwidth
     // see SX1276/77/78 Errata, section 2.1 for details
-    if(abs(_bw - 500.0) <= 0.001) {
+    if(fabs(_bw - 500.0) <= 0.001) {
       if((freq >= 862.0) && (freq <= 1020.0)) {
         _mod->SPIwriteRegister(0x36, 0x02);
         _mod->SPIwriteRegister(0x3a, 0x64);
@@ -69,49 +69,49 @@ int16_t SX1276::setFrequency(float freq) {
 
     // mitigation of receiver spurious response
     // see SX1276/77/78 Errata, section 2.3 for details
-    if(abs(_bw - 7.8) <= 0.001) {
+    if(fabs(_bw - 7.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x48);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 7.8;
-    } else if(abs(_bw - 10.4) <= 0.001) {
+    } else if(fabs(_bw - 10.4) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 10.4;
-    } else if(abs(_bw - 15.6) <= 0.001) {
+    } else if(fabs(_bw - 15.6) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 15.6;
-    } else if(abs(_bw - 20.8) <= 0.001) {
+    } else if(fabs(_bw - 20.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 20.8;
-    } else if(abs(_bw - 31.25) <= 0.001) {
+    } else if(fabs(_bw - 31.25) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 31.25;
-    } else if(abs(_bw - 41.7) <= 0.001) {
+    } else if(fabs(_bw - 41.7) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 41.7;
-    } else if(abs(_bw - 62.5) <= 0.001) {
+    } else if(fabs(_bw - 62.5) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 125.0) <= 0.001) {
+    } else if(fabs(_bw - 125.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 250.0) <= 0.001) {
+    } else if(fabs(_bw - 250.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 500.0) <= 0.001) {
+    } else if(fabs(_bw - 500.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b1000000, 7, 7);
     }
   }
diff --git a/src/modules/SX127x/SX1277.cpp b/src/modules/SX127x/SX1277.cpp
index 2a5a942e..86f58d5e 100644
--- a/src/modules/SX127x/SX1277.cpp
+++ b/src/modules/SX127x/SX1277.cpp
@@ -57,7 +57,7 @@ int16_t SX1277::setFrequency(float freq) {
   if(getActiveModem() == SX127X_LORA) {
     // sensitivity optimization for 500kHz bandwidth
     // see SX1276/77/78 Errata, section 2.1 for details
-    if(abs(_bw - 500.0) <= 0.001) {
+    if(fabs(_bw - 500.0) <= 0.001) {
       if((freq >= 862.0) && (freq <= 1020.0)) {
         _mod->SPIwriteRegister(0x36, 0x02);
         _mod->SPIwriteRegister(0x3a, 0x64);
@@ -69,49 +69,49 @@ int16_t SX1277::setFrequency(float freq) {
 
     // mitigation of receiver spurious response
     // see SX1276/77/78 Errata, section 2.3 for details
-    if(abs(_bw - 7.8) <= 0.001) {
+    if(fabs(_bw - 7.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x48);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 7.8;
-    } else if(abs(_bw - 10.4) <= 0.001) {
+    } else if(fabs(_bw - 10.4) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 10.4;
-    } else if(abs(_bw - 15.6) <= 0.001) {
+    } else if(fabs(_bw - 15.6) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 15.6;
-    } else if(abs(_bw - 20.8) <= 0.001) {
+    } else if(fabs(_bw - 20.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 20.8;
-    } else if(abs(_bw - 31.25) <= 0.001) {
+    } else if(fabs(_bw - 31.25) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 31.25;
-    } else if(abs(_bw - 41.7) <= 0.001) {
+    } else if(fabs(_bw - 41.7) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 41.7;
-    } else if(abs(_bw - 62.5) <= 0.001) {
+    } else if(fabs(_bw - 62.5) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 125.0) <= 0.001) {
+    } else if(fabs(_bw - 125.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 250.0) <= 0.001) {
+    } else if(fabs(_bw - 250.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 500.0) <= 0.001) {
+    } else if(fabs(_bw - 500.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b1000000, 7, 7);
     }
   }
diff --git a/src/modules/SX127x/SX1278.cpp b/src/modules/SX127x/SX1278.cpp
index fbf2f766..b309c9b8 100644
--- a/src/modules/SX127x/SX1278.cpp
+++ b/src/modules/SX127x/SX1278.cpp
@@ -74,7 +74,7 @@ int16_t SX1278::setFrequency(float freq) {
   if(getActiveModem() == SX127X_LORA) {
     // sensitivity optimization for 500kHz bandwidth
     // see SX1276/77/78 Errata, section 2.1 for details
-    if(abs(_bw - 500.0) <= 0.001) {
+    if(fabs(_bw - 500.0) <= 0.001) {
       if((freq >= 862.0) && (freq <= 1020.0)) {
         _mod->SPIwriteRegister(0x36, 0x02);
         _mod->SPIwriteRegister(0x3a, 0x64);
@@ -86,49 +86,49 @@ int16_t SX1278::setFrequency(float freq) {
 
     // mitigation of receiver spurious response
     // see SX1276/77/78 Errata, section 2.3 for details
-    if(abs(_bw - 7.8) <= 0.001) {
+    if(fabs(_bw - 7.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x48);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 7.8;
-    } else if(abs(_bw - 10.4) <= 0.001) {
+    } else if(fabs(_bw - 10.4) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 10.4;
-    } else if(abs(_bw - 15.6) <= 0.001) {
+    } else if(fabs(_bw - 15.6) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 15.6;
-    } else if(abs(_bw - 20.8) <= 0.001) {
+    } else if(fabs(_bw - 20.8) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 20.8;
-    } else if(abs(_bw - 31.25) <= 0.001) {
+    } else if(fabs(_bw - 31.25) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 31.25;
-    } else if(abs(_bw - 41.7) <= 0.001) {
+    } else if(fabs(_bw - 41.7) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x44);
       _mod->SPIsetRegValue(0x30, 0x00);
       freq += 41.7;
-    } else if(abs(_bw - 62.5) <= 0.001) {
+    } else if(fabs(_bw - 62.5) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 125.0) <= 0.001) {
+    } else if(fabs(_bw - 125.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 250.0) <= 0.001) {
+    } else if(fabs(_bw - 250.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b0000000, 7, 7);
       _mod->SPIsetRegValue(0x2F, 0x40);
       _mod->SPIsetRegValue(0x30, 0x00);
-    } else if(abs(_bw - 500.0) <= 0.001) {
+    } else if(fabs(_bw - 500.0) <= 0.001) {
       _mod->SPIsetRegValue(0x31, 0b1000000, 7, 7);
     }
   }
@@ -150,25 +150,25 @@ int16_t SX1278::setBandwidth(float bw) {
   uint8_t newBandwidth;
 
   // check allowed bandwidth values
-  if(abs(bw - 7.8) <= 0.001) {
+  if(fabs(bw - 7.8) <= 0.001) {
     newBandwidth = SX1278_BW_7_80_KHZ;
-  } else if(abs(bw - 10.4) <= 0.001) {
+  } else if(fabs(bw - 10.4) <= 0.001) {
     newBandwidth = SX1278_BW_10_40_KHZ;
-  } else if(abs(bw - 15.6) <= 0.001) {
+  } else if(fabs(bw - 15.6) <= 0.001) {
     newBandwidth = SX1278_BW_15_60_KHZ;
-  } else if(abs(bw - 20.8) <= 0.001) {
+  } else if(fabs(bw - 20.8) <= 0.001) {
     newBandwidth = SX1278_BW_20_80_KHZ;
-  } else if(abs(bw - 31.25) <= 0.001) {
+  } else if(fabs(bw - 31.25) <= 0.001) {
     newBandwidth = SX1278_BW_31_25_KHZ;
-  } else if(abs(bw - 41.7) <= 0.001) {
+  } else if(fabs(bw - 41.7) <= 0.001) {
     newBandwidth = SX1278_BW_41_70_KHZ;
-  } else if(abs(bw - 62.5) <= 0.001) {
+  } else if(fabs(bw - 62.5) <= 0.001) {
     newBandwidth = SX1278_BW_62_50_KHZ;
-  } else if(abs(bw - 125.0) <= 0.001) {
+  } else if(fabs(bw - 125.0) <= 0.001) {
     newBandwidth = SX1278_BW_125_00_KHZ;
-  } else if(abs(bw - 250.0) <= 0.001) {
+  } else if(fabs(bw - 250.0) <= 0.001) {
     newBandwidth = SX1278_BW_250_00_KHZ;
-  } else if(abs(bw - 500.0) <= 0.001) {
+  } else if(fabs(bw - 500.0) <= 0.001) {
     newBandwidth = SX1278_BW_500_00_KHZ;
   } else {
     return(ERR_INVALID_BANDWIDTH);
diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 2f6e3e87..160ce048 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -763,7 +763,7 @@ uint8_t SX127x::calculateBWManExp(float bandwidth)
   for(uint8_t e = 7; e >= 1; e--) {
     for(int8_t m = 2; m >= 0; m--) {
       float point = (SX127X_CRYSTAL_FREQ * 1000000.0)/(((4 * m) + 16) * ((uint32_t)1 << (e + 2)));
-      if(abs(bandwidth - ((point / 1000.0) + 0.05)) <= 0.5) {
+      if(fabs(bandwidth - ((point / 1000.0) + 0.05)) <= 0.5) {
         return((m << 3) | e);
       }
     }