Merge pull request #1 from sparkfun/Avoid_Ambiguity

Avoid ambiguity

Author: PaulZC

.github/workflows/compile-sketch.yml

@@ -4,7 +4,6 @@ on:
   # - push 
   - pull_request
 
-
 jobs:
   compile-sketch:
     runs-on: ubuntu-latest
@@ -94,12 +93,16 @@ jobs:
       - name: Compile Sketch
         uses: arduino/compile-sketches@v1.1.0
         with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
           platforms: ${{ matrix.board.platforms }}
           fqbn: ${{ matrix.board.fqbn }}
           libraries: |
             - source-path: ./
+            # Add library dependencies here: 
+            - source-url: https://github.com/sparkfun/SparkFun_Toolkit.git
+            # - name: name-of-library-registered-with-arduino-library-manager
           sketch-paths: |
-            - examples/Example01_Basic_SingleShot
+            - examples/Example05_AlternateAddress
           enable-warnings-report: true
           enable-deltas-report: true
           verbose: true

src/SparkFun_ADS1219.cpp

@@ -126,12 +126,17 @@ bool SfeADS1219Driver::readConversion()
     if (result)
     {
         // Data is 3-bytes (24-bits), big-endian (MSB first).
-        _adcResult = rawBytes[0];
-        _adcResult = (_adcResult << 8) | rawBytes[1];
-        _adcResult = (_adcResult << 8) | rawBytes[2];
+        union {
+            int32_t i32;
+            uint32_t u32;
+        } iu32; // Use a union to avoid signed / unsigned ambiguity
+        iu32.u32 = rawBytes[0];
+        iu32.u32 = (iu32.u32 << 8) | rawBytes[1];
+        iu32.u32 = (iu32.u32 << 8) | rawBytes[2];
         // Preserve the 2's complement.
-        if (_adcResult & (1 << 23))
-            _adcResult |= 0xFF000000;
+        if (0x00100000 == (iu32.u32 & 0x00100000))
+            iu32.u32 = iu32.u32 | 0xFF000000;
+        _adcResult = iu32.i32; // Store the signed result
     }
     return result;
 }

src/SparkFun_ADS1219.h

@@ -230,7 +230,7 @@ class SfeADS1219Driver
 
     ads1219_gain_config_t _adcGain; // Local configuration value. ADC gain - needed for conversion to mV.
 
-    int32_t _adcResult; // Local store for the ADC conversion result. 24-Bit, shifted left for correct 2's complement
+    int32_t _adcResult; // Local store for the ADC conversion result. 24-Bit, 2's complement
 };
 
 class SfeADS1219ArdI2C : public SfeADS1219Driver