update u8g2lib + working display

MilliOhmMeter_FW/src/measure_hall.cpp

@@ -0,0 +1,42 @@
+#include "measure_hall.h"
+
+TwoWire wire();
+Adafruit_ADS1115 ads; /* Use this for the 12-bit version */
+uint64_t lastMeasurement = 0;
+float ADCvolts = 0;
+
+void initMeasureHall(void)
+{
+  log_i("init ADC");
+  if(!Wire.setPins(ADC_SDA, ADC_SCL))
+  {
+    log_e("FAILED to set i2c pins");
+    return;
+  }
+  if (!ads.begin())
+  {
+    log_e("Failed to initialize ADS.");
+    return;
+  }
+  else
+  {
+    log_i("init ADC OK");
+  }
+  lastMeasurement = millis();
+}
+
+void handleMeasureHall(void)
+{
+  uint64_t currentmillis = millis();
+  if (currentmillis - lastMeasurement > MEASUREMENTINTERVAL)
+  {
+    ADCvolts = ads.computeVolts(ads.readADC_SingleEnded(MEAS_CHANNEL));
+
+    lastMeasurement = currentmillis;
+  }
+}
+
+float getMeasurement(void)
+{
+  return ADCvolts;
+}