61 lines
1.9 KiB
C#
61 lines
1.9 KiB
C#
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using System;
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using Microsoft.SPOT;
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using Microsoft.SPOT.Hardware;
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using GHIElectronics.NETMF.Hardware;
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namespace PlaneOnBoardSoftware
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{
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class BatteryMonitor
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{
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AnalogIn aiPortU;
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AnalogIn aiPortI;
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static float CurrentOffSet = 1.477f;
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static float ShuntResistens = 0.005776f;
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static float ShuntGain = 100.0f;
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static float CurrFactor = 1 / ShuntGain / ShuntResistens;
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float _voltage;
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float _current;
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double _charge = 0;
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double _energy = 0;
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DateTime lastTimePoint = DateTime.Now;
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public float Voltage { get { return _voltage; } }
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public float Current { get { return _current; } }
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public float Charge { get { return (float)_charge; } }
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public float Energy { get { return (float)_energy; } }
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public BatteryMonitor(AnalogIn VoltageAnalogInPort, AnalogIn CurrentAnalogInPort)
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{
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aiPortU = VoltageAnalogInPort;
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aiPortI = CurrentAnalogInPort;
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aiPortU.SetLinearScale(0, 4861); //mV (4.8V = 3.3V*(22kOhm+10kOhm)/22kOhm), 4.861V <- calibration
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aiPortI.SetLinearScale(0, 3300); //mV
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}
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public void UpdateData()
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{
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float dt;
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DateTime newTime = DateTime.UtcNow;
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dt = newTime.Subtract(lastTimePoint).Ticks / (float)TimeSpan.TicksPerSecond;
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lastTimePoint = newTime;
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_voltage = aiPortU.Read() * 0.001f; //in V
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if (_voltage > 2.0f)
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_current = (CurrentOffSet - aiPortI.Read() * 0.001f) * CurrFactor; //in A (1 V/A)
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else
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_current = 0;
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if (dt > 0 && dt < 10)
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{
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_charge += _current * dt / 3.6f;
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_energy += _current * _voltage * dt;
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}
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}
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}
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}
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