Merge branch 'virtualcurrent' of https://github.com/tracernz/cleanflight into tracernz-virtualcurrent

docs/Battery.md

@@ -74,8 +74,19 @@ Enable current monitoring using the CLI command
 feature CURRENT_METER
 ```
 
+Configure the current meter type using the `current_meter_type` settings as per the following table.
+
+| Value | Sensor Type            |
+| ----- | ---------------------- | 
+| 0     | None                   |
+| 1     | ADC/hardware sensor    |
+| 2     | Virtual sensor         |
+
 Configure capacity using the `battery_capacity` setting, which takes a value in mAh.
 
+If you're using an OSD that expects the multiwii current meter output value, then set `multiwii_current_meter_output` to `1` (this multiplies amperage sent to MSP by 10).
+
+### ADC Sensor
 The current meter may need to be configured so that the value read at the ADC input matches actual current draw.  Just like you need a voltmeter to correctly calibrate your voltage reading you also need an ammeter to calibrate your current sensor.
 
 Use the following settings to adjust calibration. 
@@ -83,4 +94,23 @@ Use the following settings to adjust calibration.
 `current_meter_scale`
 `current_meter_offset`
 
-If you're using an OSD that expects the multiwii current meter output value, then set `multiwii_current_meter_output` to `1`.
+### Virtual Sensor
+The virtual sensor uses the throttle position to calculate as estimated current value. This is useful when a real sensor is not available. The following settings adjust the calibration.
+
+| Setting                       | Description                                              |
+| ----------------------------- | -------------------------------------------------------- | 
+| `current_meter_scale`      | The throttle scaling factor [centiamps, i.e. 1/100th A]  |
+| `current_meter_offset`     | The current at zero throttle [centiamps, i.e. 1/100th A] |
+
+If you know your current at zero throttle (Imin) and maximum throttle(Imax) you can calculate the scaling factors using the following formulas where Tmax is maximum throttle offset (i.e. for `max_throttle` = 1850, Tmax = 1850 - 1000 = 850):
+```
+current_meter_scale = (Imax - Imin) * 100000 / (Tmax + (Tmax * Tmax / 50))
+current_meter_offset = Imin * 100
+```
+e.g. For a maximum current of 34.2 A and minimum current of 2.8 A with `max_throttle` = 1850
+```
+current_meter_scale = (Imax - Imin) * 100000 / (Tmax + (Tmax * Tmax / 50))
+                    = (34.2 - 2.8) * 100000 / (850 + (850 * 850 / 50))
+                    = 205
+current_meter_offset = Imin * 100 = 280
+```

src/main/config/config.c

@@ -227,7 +227,7 @@ void resetBatteryConfig(batteryConfig_t *batteryConfig)
     batteryConfig->currentMeterOffset = 0;
     batteryConfig->currentMeterScale = 400; // for Allegro ACS758LCB-100U (40mV/A)
     batteryConfig->batteryCapacity = 0;
-
+    batteryConfig->currentMeterType = CURRENT_SENSOR_ADC;
 }
 
 void resetSerialConfig(serialConfig_t *serialConfig)

src/main/io/serial_cli.c

@@ -305,7 +305,7 @@ const clivalue_t valueTable[] = {
     { "current_meter_scale",        VAR_INT16 | MASTER_VALUE,  &masterConfig.batteryConfig.currentMeterScale, -10000, 10000 },
     { "current_meter_offset",       VAR_UINT16 | MASTER_VALUE,  &masterConfig.batteryConfig.currentMeterOffset, 0, 3300 },
     { "multiwii_current_meter_output", VAR_UINT8  | MASTER_VALUE,  &masterConfig.batteryConfig.multiwiiCurrentMeterOutput, 0, 1 },
-
+    { "current_meter_type",         VAR_UINT8  | MASTER_VALUE,  &masterConfig.batteryConfig.currentMeterType, 0, CURRENT_SENSOR_MAX },
 
     { "align_gyro",                 VAR_UINT8  | MASTER_VALUE,  &masterConfig.sensorAlignmentConfig.gyro_align, 0, 8 },
     { "align_acc",                  VAR_UINT8  | MASTER_VALUE,  &masterConfig.sensorAlignmentConfig.acc_align, 0, 8 },

src/main/main.c

@@ -290,7 +290,8 @@ void init(void)
     pwm_params.useSoftSerial = feature(FEATURE_SOFTSERIAL);
     pwm_params.useParallelPWM = feature(FEATURE_RX_PARALLEL_PWM);
     pwm_params.useRSSIADC = feature(FEATURE_RSSI_ADC);
-    pwm_params.useCurrentMeterADC = feature(FEATURE_CURRENT_METER);
+    pwm_params.useCurrentMeterADC = feature(FEATURE_CURRENT_METER)
+        && masterConfig.batteryConfig.currentMeterType == CURRENT_SENSOR_ADC;
     pwm_params.useLEDStrip = feature(FEATURE_LED_STRIP);
     pwm_params.usePPM = feature(FEATURE_RX_PPM);
     pwm_params.useOneshot = feature(FEATURE_ONESHOT125);

src/main/sensors/battery.c

@@ -20,9 +20,14 @@
 
 #include "common/maths.h"
 
+#include "config/runtime_config.h"
+
 #include "drivers/adc.h"
 #include "drivers/system.h"
 
+#include "rx/rx.h"
+#include "io/rc_controls.h"
+
 #include "sensors/battery.h"
 
 // Battery monitoring stuff
@@ -113,10 +118,26 @@ void updateCurrentMeter(int32_t lastUpdateAt)
 {
     static int32_t amperageRaw = 0;
     static int64_t mAhdrawnRaw = 0;
+    int32_t throttleOffset = (int32_t)rcCommand[THROTTLE] - 1000;
+    int32_t throttleFactor = 0;
 
+    switch(batteryConfig->currentMeterType) {
+        case CURRENT_SENSOR_ADC:
             amperageRaw -= amperageRaw / 8;
             amperageRaw += (amperageLatestADC = adcGetChannel(ADC_CURRENT));
             amperage = currentSensorToCentiamps(amperageRaw / 8);
+            break;
+        case CURRENT_SENSOR_VIRTUAL:
+            amperage = (int32_t)batteryConfig->currentMeterOffset;
+            if(ARMING_FLAG(ARMED)) {
+                throttleFactor = throttleOffset + (throttleOffset * throttleOffset / 50);
+                amperage += throttleFactor * (int32_t)batteryConfig->currentMeterScale  / 1000;
+            }
+            break;
+        case CURRENT_SENSOR_NONE:
+            amperage = 0;
+            break;
+    }
 
     mAhdrawnRaw += (amperage * lastUpdateAt) / 1000;
     mAhDrawn = mAhdrawnRaw / (3600 * 100);

src/main/sensors/battery.h

@@ -21,6 +21,13 @@
 #define VBAT_SCALE_MIN 0
 #define VBAT_SCALE_MAX 255
 
+typedef enum {
+    CURRENT_SENSOR_NONE = 0,
+    CURRENT_SENSOR_ADC,
+    CURRENT_SENSOR_VIRTUAL,
+    CURRENT_SENSOR_MAX = CURRENT_SENSOR_VIRTUAL
+} currentSensor_e;
+
 typedef struct batteryConfig_s {
     uint8_t vbatscale;                      // adjust this to match battery voltage to reported value
     uint8_t vbatmaxcellvoltage;             // maximum voltage per cell, used for auto-detecting battery voltage in 0.1V units, default is 43 (4.3V)
@@ -29,6 +36,7 @@ typedef struct batteryConfig_s {
 
     int16_t currentMeterScale;             // scale the current sensor output voltage to milliamps. Value in 1/10th mV/A
     uint16_t currentMeterOffset;            // offset of the current sensor in millivolt steps
+    currentSensor_e  currentMeterType;      // type of current meter used, either ADC or virtual
 
     // FIXME this doesn't belong in here since it's a concern of MSP, not of the battery code.
     uint8_t multiwiiCurrentMeterOutput;     // if set to 1 output the amperage in milliamp steps instead of 0.01A steps via msp