;;
  ;;  mur.sat
  ;;
  ;;  Somewhen in the year 20xx, mur.at will have a nano satellite launched
  ;;  into a low earth orbit (310 km above the surface of our planet). The
  ;;  satellite itself is a TubeSat personal satellite kit, developed and
  ;;  launched by interorbital systems. mur.sat is a joint venture of mur.at,
  ;;  ESC im Labor and realraum.
  ;;
  ;;  Please visit the project hompage at sat.mur.at for further information.
  ;;
  ;;
  ;;  Copyright (C) 2011-2015 Christian Pointner <equinox@mur.at>
  ;;
  ;;  This file is part of mur.sat.
  ;;
  ;;  mur.sat is free software: you can redistribute it and/or modify
  ;;  it under the terms of the GNU General Public License as published by
  ;;  the Free Software Foundation, either version 3 of the License, or
  ;;  any later version.
  ;;
  ;;  mur.sat is distributed in the hope that it will be useful,
  ;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
  ;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ;;  GNU General Public License for more details.
  ;;
  ;;  You should have received a copy of the GNU General Public License
  ;;  along with mur.sat. If not, see <http://www.gnu.org/licenses/>.
  ;;
  ;; -------------------------------------
  ;; DEFINES
  ;;   constants
sol_calc_power_single
  clrf      SOL_CALC_0
  clrf      SOL_CALC_1
  clrf      SOL_CALC_2
  movlw     .4
  movwf     SOL_CALC_CNT

  ;; sum up all currents -> SOL_CALC_0:2
sol_sum_current
  movf      INDF,w
  bcf       STATUS,C
  addwf     SOL_CALC_0,f
  btfsc     STATUS,C
  incf      SOL_CALC_1,f
  incf      FSR,f
  decfsz    SOL_CALC_CNT,f
  goto      sol_sum_current

  movf      INDF,w
  movwf     SOL_CALC_9
  clrf      SOL_CALC_3
  clrf      SOL_CALC_4
  clrf      SOL_CALC_5

  ;; multiply SOL_CALC_0:2 with SOL_CALC_9 -> SOL_CALC_3:5
  movlw     .8
  movwf     SOL_CALC_CNT
sol_mula_vc
  btfss     SOL_CALC_9,0
  goto      sol_mula_rotate

  bcf       STATUS,C
  movf      SOL_CALC_0,w
  addwf     SOL_CALC_3,f
  btfss     STATUS,C
  goto      sol_mula_vc1
  bcf       STATUS,C
  movlw     .1
  addwf     SOL_CALC_4,f
  btfsc     STATUS,C
  incf      SOL_CALC_5,f

sol_mula_vc1
  bcf       STATUS,C
  movf      SOL_CALC_1,w
  addwf     SOL_CALC_4,f
  btfsc     STATUS,C
  incf      SOL_CALC_5,f

  movf      SOL_CALC_2,w
  addwf     SOL_CALC_5,f

sol_mula_rotate
  rrf       SOL_CALC_9,f
  bcf       STATUS,C
  rlf       SOL_CALC_0,f
  rlf       SOL_CALC_1,f
  rlf       SOL_CALC_2,f

  decfsz    SOL_CALC_CNT,f
  goto      sol_mula_vc

  return

  ;; -------------------------------------
solar_calc_power
  ;; calc power of power line 1
  movlw     ADC_SOLAR_C0
  movwf     FSR
  call      sol_calc_power_single

  ;; move SOL_CALC_3:5 -> SOL_CALC_6:8
  movf      SOL_CALC_3,w
  movwf     SOL_CALC_6
  movf      SOL_CALC_4,w
  movwf     SOL_CALC_7
  movf      SOL_CALC_5,w
  movwf     SOL_CALC_8

  ;; calc power of power line 2
  movlw     ADC_SOLAR_C4
  movwf     FSR
  call      sol_calc_power_single

  ;; add SOL_CALC_3:5 to SOL_CALC_6:8 -> SOL_CALC_6:8
  bcf       STATUS,C
  movf      SOL_CALC_3,w
  addwf     SOL_CALC_6,f
  btfss     STATUS,C
  goto      solar_calc_power1
  bcf       STATUS,C
  movlw     .1
  addwf     SOL_CALC_7,f
  btfsc     STATUS,C
  incf      SOL_CALC_8,f

solar_calc_power1
  movf      SOL_CALC_4,w
  addwf     SOL_CALC_7,f
  btfsc     STATUS,C
  incf      SOL_CALC_8,f

  movf      SOL_CALC_5,w
  addwf     SOL_CALC_8,f

  ;; SOL_CALC_6:8 << 1   ->   SOL_CALC_6:8
  rlf       SOL_CALC_6,f
  rlf       SOL_CALC_7,f
  rlf       SOL_CALC_8,f

  ;; if(SOL_CALC_6 & 0x80) SOL_CALC_7:8+=1
  bcf       STATUS,C
  movlw     .1
  btfsc     SOL_CALC_6,7
  addwf     SOL_CALC_7,f
  btfsc     STATUS,C
  incf      SOL_CALC_8,f

  ;; SOL_CALC_7 -> SOL_POWERL, SOL_CALC_8 -> SOL_POWERH
  movf      SOL_CALC_7,w
  movwf     SOL_POWERL
  movf      SOL_CALC_8,w
  movwf     SOL_POWERH

  return
  ;; -------------------------------------