altoslib: Fix EasyMini voltage computations

[fw/altos] / altoslib / AltosConvert.java

diff --git a/altoslib/AltosConvert.java b/altoslib/AltosConvert.java
index 8f214c8b40c7a80fc6778a3b6806e471b76b7ad6..35923ec3c3dbd1308e2f6d75b1959fcc760efa71 100644 (file)
--- a/altoslib/AltosConvert.java
+++ b/altoslib/AltosConvert.java
@@ -224,10 +224,21 @@ public class AltosConvert {
                return sensor / 32767.0 * supply * 127/27;
        }
 
-       static double easy_mini_voltage(int sensor) {
-               double  supply = 3.0;
+       static double easy_mini_voltage(int sensor, int serial) {
+               double  supply = 3.3;
+               double  diode_offset = 0.0;
 
-               return sensor / 32767.0 * supply * 127/27;
+               /* early prototypes had a 3.0V regulator */
+               if (serial < 1000)
+                       supply = 3.0;
+
+               /* Purple v1.0 boards had the sensor after the
+                * blocking diode, which drops about 150mV
+                */
+               if (serial < 1665)
+                       diode_offset = 0.150;
+
+               return sensor / 32767.0 * supply * 127/27 + diode_offset;
        }
 
        public static double radio_to_frequency(int freq, int setting, int cal, int channel) {