Tiny13 Led Solar Tracker @ 9.6 Mhz by John-Alfred Ullasmann
As a further development of the Opto Circuit, I thought I would bring you up to speed with the current state of my experimental research.
Suppose it were possible to design and build a Solar Tracker Circuit for less than $2 , who wouldn’t be interested in hearing more about this ?
What if this circuit could output the current position of the sun in Degrees with an accuracy of 1 part in 256 using an 8 Bit and 1 part in 1024 using a 10 Bit A2D ?
If, in addition, the Circuit could output the total incident sunlight falling on the 4 compass Headings, would that not make this circuit almost irresistible ?
All the best from sunny Germany.
John-Alfred Ullasmann
As a further development of the Opto Circuit, I thought I would bring you up to speed with the current state of my experimental research.
Suppose it were possible to design and build a Solar Tracker Circuit for less than $2 , who wouldn’t be interested in hearing more about this ?
What if this circuit could output the current position of the sun in Degrees with an accuracy of 1 part in 256 using an 8 Bit and 1 part in 1024 using a 10 Bit A2D ?
If, in addition, the Circuit could output the total incident sunlight falling on the 4 compass Headings, would that not make this circuit almost irresistible ?
All the best from sunny Germany.
John-Alfred Ullasmann
| CODE |
; Tiny13 Led Solar Tracker @ 9.6 Mhz ;----- .include "tn13def.inc" ;------------------------------------------------------------------------------------------------ .def RemLo = r6 ; 16 Bit Division Remainder .def RemHi = r7 .def LiteLo = r8 ; 16 Bit Light Level .def LiteHi = r9 .def StorLo = r10 ; 16 Bit Division Temporary Store Register .def StorHi = r11 .def ValLo = r12 ; 16 Bit A2D Average .def ValHi = r13 .def BytOut = r14 ; 8 Bit Serial Out Register .def LupCnt = r15 ; 256 A2D Sample Counter .def Temp = r16 ; Work Register A .def Work = r17 ; Work Register B .def BitCnt = r18 ; Serial Output Bit Counter .def SrtCnt = r18 ; Sort Routine Loop Count .def BitDly = r19 ; 104 uS Delay Constant .def DivCnt = r19 ; 16 Bit Division Routine Bit Count .def ConCnt = r20 ; A2D Loop Count .def DisPin = r21 ; Discharge Pin .def LuxLo = r20 ; 2 Highest Light 8 Bit Values .def LuxHi = r21 .def DivrLo = r20 ; 16 Bit Divider .def DivrHi = r21 .def WordLo = r20 ; 16 Bit Serial Out Word .def WordHi = r21 .def DirLo = r20 ; 2 Highest Direction 8 Bit Values .def DirHi = r21 .def DivdLo = r22 ; 16 Bit Dividend .def DivdHi = r23 .def HoldB = r22 ; Sort Temporary Hold Registers .def HoldA = r23 .def ResLo = r22 ; 16 Bit Result .def ResHi = r23 .def MulLo = r22 ; 16 Bit Multiplicand .def MulHi = r23 .def DirInd = r22 ; Compass Direction Select Register .def AdcSel = r23 ; A2D Multiplexor Select Register ;------------------------------------------------------------------------------------------------ .Cseg .Org $0000 ;------------------------------------------------------------------------------------------------ Reset: ldi Temp, RamEnd out Spl, Temp ; Set Stack Pointer sbi AcsR, Acd ; Disable Comparator Ldi Temp, $3c ; Disable all AdcD Digital Inputs out DidR0, Temp ldi Temp, $87 ; Init A2D + 75 Khz Sample Rate out AdCsrA, Temp ldi YH, $00 ; Set YH Constant to Zero clr LupCnt ; 256 Sample Counter ;------------------------------------------------------------------------------------------------ Main: ldi YL, LuxBuf+$00 ; Point YL to Light Value Start ldi AdcSel, $60 ; Adc0 + ( AdLar = 1 ) + 1.1V Ref ldi DirInd, $00 ; Direction Identifier ldi DisPin, $01 ; Mark on PB0 + Discharge Led clr LiteHi ; Clear 16-Bit Light Level clr LiteLo ldi ConCnt, 4 ; Conversion Loop Count = 4 Leds rcall Convert ; Do A2D Conversion dec ConCnt brne pc-2 ; 4 * 256 samples finished ? rcall Sort ; Bubble Sort Results in Ascending order rcall Intensity ; Get the 2 Brightest Light Values rcall Mul90 ; Multiply Result by Ninety rcall Divide ; 16 Bit Division rcall Compass ; Get Compass Quadrant in Degrees rcall Send ; Transmit Data Stream rjmp Main ; Go back ;------------------------------------------------------------------------------------------------ Convert: ;* This routine gets 256* A2D, 8-Bit samples on each Led. These samples are then averaged and ;* integrated in "ValHi:ValLo" and the final result is divided by 256 and is stored in "Valhi" ;* This value is then placed in the Ram locations ;* starting @ "LuxBuf+$00" using Y register Post Indexing. ;* The Compass Point Direction "DirInd" 8-Bit values (N,E,S,W) are similarly stored ;* in the Ram locations starting @ "LuxBuf+$00" using Y register offset by + $04 ;* The total light incidence falling on the 4 Leds is likewise averaged over 256 samples and is ;* stored in Registers "LiteHi:LiteLo" ;* "AdcSel" is incremented after each pass and is used to select the appropriate A2D Mux Input ;* (00,01,02,03) ;* "DisPin" is also incremented after each pass and is used to "discharge" the appropriate ;* Led by bringing the corresponding Mux Input Low out AdMux, AdcSel ; AdcN + (AdLar=1) + Int Voltage Ref clr ValLo ; Clr Result Registers clr ValHi clr LiteLo ; Clr Accumulated Light Registers clr LiteHi ConLup: sbi AdCsrA, Adsc ; En A/D Conv sbis AdCsrA, Adif ; Conv Comp ? rjmp pc-1 sbi AdCsrA, Adif ; Clr Conversion Flag in Temp, AdcH ; Read Hi order 8 Bits adc ValLo, Temp ; Integrate adc ValHi, YH dec LupCnt ; 256 samples done ? brne ConLup st Y+, ValHi ; Store Value in LuxBuf+$nn + Increment Y std Y+4, DirInd ; Put Direction in LuxBuf+$nn offset by 4 add LiteLo, ValHi ; Update accumulated Light Level adc LiteHi, YH ; Adc Null Constant out DdrB, DisPin ; Discharge Direction Led ldi Temp, $01 ; Disharge Led Voltage out PortB, Temp out DdrB, Temp ; ReEnable Mark on PB0 out PortB, Temp inc AdcSel ; Select Next Led inc DisPin ; Select Next Discharge Pin inc DirInd ; Select Next Direction Indicator ret ;------------------------------------------------------------------------------------------------ Sort: ;* This routine Bubble Sorts the Four 8-Bit Light Values starting @ Ram Location "LuxBuf+0". ;* The corresponding Direction Indicators starting @ Ram Location "LuxBuf+4" are also sorted. ldi SrtCnt, $04 ; Sort Loop Counter = 4 OutLup: ldi YL, LuxBuf+3 ; Point to End of Light values ld HoldA, Y ; Get First Value in HoldA ld HoldB, -Y ; Get 2nd Value in HoldB cp HoldA, HoldB ; Compare both values and ... brlo ChkLup st Y, HoldA ; Swap A and B if A>B std Y+1, HoldB ldd HoldA, Y+5 ; Do same with Direction Indicators ldd HoldB , Y+4 std Y+4, HoldA ; Swap Indicators std Y+5, HoldB ChkLup: cpi YL, LuxBuf+0 ; Loop Inner if not finished brne OutLup+1 dec SrtCnt ; Loop to back OutLup if NOT finished brne OutLup ret ;------------------------------------------------------------------------------------------------ Intensity: ;* This routine fetches the 2 Brightest Light Intensities and prepares ;* the result in Degrees according to the Formula ;* ;* ((Highest Lux Value / (Highest Lux Value + 2nd Highest Value)) * 90) + Compass point ld LuxHi, Y+ ; Highest + 2nd Highest Light Values ld LuxLo, Y mov MulLo, LuxHi ; Copy LuxHi into MulLo add LuxLo, LuxHi ; Add Highest to 2nd Highest Light Value clr LuxHi adc LuxHi, YH ; Adc Zero Constant ret ;------------------------------------------------------------------------------------------------ Mul90: ;* This routine multiplies the 8-bit number "MulLo" by 90 ;* using just Shifts and Adds. The 16-bit result is placed in "MulHi:MulLo". clr StorLo ; Temp Holding Store clr StorHi clr MulHi ; Clear High Byte Result lsl MulLo ; Multiplicand * 2 rol MulHi add StorLo, MulLo ; Add to Holding adc StorHi, MulHi lsl MulLo ; Multiplicand * 8 rol MulHi lsl MulLo rol MulHi add StorLo, MulLo ; Add to Holding adc StorHi, MulHi lsl MulLo ; Multiplicand * 16 rol MulHi add StorLo, MulLo ; Add to Holding adc StorHi, MulHi lsl MulLo ; Multiplicand * 64 rol MulHi lsl MulLo rol MulHi add MulLo, StorLo ; Result = Holding + Multiplicand adc MulHi, StorHi ret ;------------------------------------------------------------------------------------------------ Divide: ;* This routine divides the two 16-bit numbers ;* "DivdHi:DivdLo" (Dividend) and "DivrHi:DivrLo" (Divisor). ;* The result is placed in "ResHi:ResLo" and the Remainder in "RemHi:RemLo". clr RemHi ; Clear Remainder Registers clr RemLo ldi DivCnt,16 ; Init Loop Counter lsl DivdLo ; Shift Left Dividend rol DivdHi rol RemLo ; Rotate Dividend into Remainder rol RemHi cp RemLo, DivrLo ; Remainder ? Divisor cpc RemHi, DivrHi brcs pc+4 ; If Result Negative then Skip inc DivdLo ; Increment Dividend Low sub RemLo, DivrLo sbc RemHi, DivrHi ; Remainder = Remainder - Divisor dec DivCnt ; If not done then Iterate brne pc-11 ret ;------------------------------------------------------------------------------------------------ Compass: ;* This routine gets the Compass Quadrant as a 16-Bit Degree Value ;* This Value is then added to the accumulated Sum in ResHi:ResLo lds Work, LuxBuf+$04 ; Get Brightest Direction lds Temp, LuxBuf+$05 ; Get Second Brightest Direction cpi Work, $00 ; = North ? breq North cpi Work, $01 ; = East ? breq East cpi Work, $02 ; = South ? breq South West: cpi Temp, $02 ; = South ? breq SWest NWest: ldi Temp, $0e ; = 270 Degrees ldi Work, $01 rjmp Exit SWest: ldi Temp, $b4 ; = 180 Degrees rjmp Bye SEast: ldi Temp, $5a ; = 90 Degrees rjmp Bye NEast: clr Temp ; = 0 Degrees Bye: clr Work ; = 0 Always Exit: add ResLo, Temp ; Add Compass Point to accumulated Sum adc ResHi, Work ret ; Return North: cpi Temp, $03 ; = West ? breq NWest rjmp NEast East: cpi Temp, $02 ; = South ? breq SEast rjmp NEast South: cpi Temp, $01 ; = East ? breq SEast rjmp SWest ;------------------------------------------------------------------------------------------------ Send: ;* This Software Uart routine running @ 9600 Bps sends 3* 16-Bit values to the Host. ;* The data stream is transmitted Byte wise using (1 Start,8 Data,1 Stop Bits) ;* The Info Packet consists of the Sun's orientation in Degrees "ResHi:ResLo" ;* The Modulo Remainder of the division routine in "RemHi:RemLo" ;* The total incident sunlight in "LiteHi:LiteLo" ;* If so desired the Delay Constant value "BitDly" can be adjusted to allow other ;* data transmission speeds. movw WordHi:WordLo,ResHi:ResLo; 16 Bit Degree Result rcall PrWord movw WordHi:WordLo,RemHi:RemLo; 16 Bit Remainder rcall PrWord movw WordHi:WordLo,LiteHi:LiteLo; 16 Bit Light Value ;------ PrWord: mov BytOut, WordHi rcall PrByt ; Send High 8 Byte mov BytOut, WordLo ; Send Low 8 Byte ;------ PrByt: mov Temp, BytOut ; Fetch BytOut swap Temp rcall NibAsc ; Nibble to Ascii mov Temp, BytOut ; Fetch BytOut once more ;------ NibAsc: andi Temp, $0f ; Mask High Nibble cpi Temp, $0a ; > 10 ? brcs pc+2 subi Temp, -$07 ; If No then Add 48+7 to Temp subi Temp, -$30 ; If No then Add only 48 to Temp ;------ PrChr: ldi BitCnt, 9 clc ; Start Bit rcall BiTime ; Out Bit lsr Temp ; Shift next bit out dec Bitcnt brne pc-3 ; Loop if Not Zero sec ; Stop Bit ;----- BiTime: brcs pc+3 ; Goto Mark cbi PortB, PortB0 ; Space Bit on PB0 rjmp Delay sbi PortB, PortB0 ; Mark Bit on PB0 nop ;----- Delay: ldi BitDly, $f8 ; Delay 104 uS nop dec BitDly ; Decrement Count and Loop brne pc-2 ret ;------------------------------------------------------------------------------------------------ .dseg .org $0060 LuxBuf: .byte 8 ; 8 Bytes for Light Values |