' {$STAMP BS2} ' {$PBASIC 2.5} 'How TO Use: ' o With power initially off, connect VIN TO 5VDC (the same voltage ' powering the sTAMP). Connect GND TO Vss. ' ' o Connect P0, P1, AND P2 ON the Stamp directly TO the CS, DATA, AND CLK ' pins ON the Digital 3-Axis Accelerometer module. ' ' o Power ON the Stamp. Download AND run this code ON the Stamp. ' ' o Acceleration values will stream back TO the computer, AND can be viewed ' on the DEBUG terminal. ' ' o The offset values FOR each axis can be calibrated by placing the device ' ON a flat horizontal surface AND adjusting the corresponding constants ' UNTIL the values FOR each axis READ (WHILE in 2g mode): ' X = 0 (0g) ' Y = 0 (0g) ' Z = 63 (+1g) ' The values already present are FOR demonstration purposes AND can ' be easily modified TO fine tune your own device. Keep in mind that ' the offset values are in 1/2 Bit increments, so FOR example, TO offset ' an axis by 5 counts, the corresponding offset would need TO be increased ' by a value of 10. See the MMA7455L device datasheet FOR more ' information. 'Offset values FOR each axis: XCal CON 25 'VAR Word YCal CON 50 'VAR word ZCal CON 0 'VAR Word CLKPin PIN 0 ' Clock Pin DATAPin PIN 1 ' Data Pin CSPin PIN 2 ' Chip Select Pin XOUTL CON $00 ' 10 bits output value X LSB XOUT[7] XOUT[6] XOUT[5] XOUT[4] XOUT[3] XOUT[2] XOUT[1] XOUT[0] XOUTH CON $01 ' 10 bits output value X MSB -- -- -- -- -- -- XOUT[9] XOUT[8] YOUTL CON $02 ' 10 bits output value Y LSB YOUT[7] YOUT[6] YOUT[5] YOUT[4] YOUT[3] YOUT[2] YOUT[1] YOUT[0] YOUTH CON $03 ' 10 bits output value Y MSB -- -- -- -- -- -- YOUT[9] YOUT[8] ZOUTL CON $04 ' 10 bits output value Z LSB ZOUT[7] ZOUT[6] ZOUT[5] ZOUT[4] ZOUT[3] ZOUT[2] ZOUT[1] ZOUT[0] ZOUTH CON $05 ' 10 bits output value Z MSB -- -- -- -- -- -- ZOUT[9] ZOUT[8] XOUT8 CON $06 ' 8 bits output value X XOUT[7] XOUT[6] XOUT[5] XOUT[4] XOUT[3] XOUT[2] XOUT[1] XOUT[0] YOUT8 CON $07 ' 8 bits output value Y YOUT[7] YOUT[6] YOUT[5] YOUT[4] YOUT[3] YOUT[2] YOUT[1] YOUT[0] ZOUT8 CON $08 ' 8 bits output value Z ZOUT[7] ZOUT[6] ZOUT[5] ZOUT[4] ZOUT[3] ZOUT[2] ZOUT[1] ZOUT[0] STATUS CON $09 ' Status registers -- -- -- -- -- PERR DOVR DRDY DETSRC CON $0A ' Detection source registers LDX LDY LDZ PDX PDY PDZ INT1 INT2 TOUT CON $0B ' "Temperature output value" (Optional) TMP[7] TMP[6] TMP[5] TMP[4] TMP[3] TMP[2] TMP[1] TMP[0] ' CON $0C ' (Reserved) -- -- -- -- -- -- -- -- I2CAD CON $0D ' I2C device address I 2CDIS DAD[6] DAD[5] DAD[4] DAD[3] DAD[2] DAD[1] DAD[0] USRINF CON $0E ' User information (Optional) UI[7] UI[6] UI[5] UI[4] UI[3] UI[2] UI[1] UI[0] WHOAMI CON $0F ' "Who am I" value (Optional) ID[7] ID[6] ID[5] ID[4] ID[3] ID[2] ID[1] ID[0] XOFFL CON $10 ' Offset drift X value (LSB) XOFF[7] XOFF[6] XOFF[5] XOFF[4] XOFF[3] XOFF[2] XOFF[1] XOFF[0] XOFFH CON $11 ' Offset drift X value (MSB) -- -- -- -- -- XOFF[10] XOFF[9] XOFF[8] YOFFL CON $12 ' Offset drift Y value (LSB) YOFF[7] YOFF[6] YOFF[5] YOFF[4] YOFF[3] YOFF[2] YOFF[1] YOFF[0] YOFFH CON $13 ' Offset drift Y value (MSB) -- -- -- -- -- YOFF[10] YOFF[9] YOFF[8] ZOFFL CON $14 ' Offset drift Z value (LSB) ZOFF[7] ZOFF[6] ZOFF[5] ZOFF[4] ZOFF[3] ZOFF[2] ZOFF[1] ZOFF[0] ZOFFH CON $15 ' Offset drift Z value (MSB) -- -- -- -- -- ZOFF[10] ZOFF[9] ZOFF[8] MCTL CON $16 ' Mode control LPEN DRPD SPI3W STON GLVL[1] GLVL[0] MOD[1] MOD[0] INTRST CON $17 ' Interrupt latch reset -- -- -- -- -- -- CLRINT2 CLRINT1 CTL1 CON $18 ' Control 1 -- THOPT ZDA YDA XDA INTRG[1] INTRG[0] INTPIN CTL2 CON $19 ' Control 2 -- -- -- -- -- DRVO PDPL LDPL LDTH CON $1A ' Level detection threshold limit value LDTH[7] LDTH[6] LDTH[5] LDTH[4] LDTH[3] LDTH[2] LDTH[1] LDTH[0] PDTH CON $1B ' Pulse detection threshold limit value PDTH[7] PDTH[6] PDTH[5] PDTH[4] PDTH[3] PDTH[2] PDTH[1] PDTH[0] PW CON $1C ' Pulse duration value PD[7] PD[6] PD[5] PD[4] PD[3] PD[2] PD[1] PD[0] LT CON $1D ' Latency time value LT[7] LT[6] LT[5] LT[4] LT[3] LT[2] LT[1] LT[0] TW CON $1E ' Time window for 2nd pulse value TW[7] TW[6] TW[5] TW[4] TW[3] TW[2] TW[1] TW[0] ' CON $1F ' (Reserved) -- -- -- -- -- -- -- -- XAccel VAR Word ' Variables to store incoming RAW data from the accelerometer YAccel VAR Word ZAccel VAR Word Xrot VAR Byte ' Variables to store New Binary Radian Yrot VAR Byte Zrot VAR Byte OldXrot VAR Byte ' Variables to store Old Binary Radian OldYrot VAR Byte OldZrot VAR Byte Address VAR Word ' Variables for reading and writing data to the accelerometer SendData VAR Byte ReceiveData VAR Byte Temp1 VAR Word ' Temp variables Temp2 VAR Word Temp3 VAR Word Chr VAR Byte 'Variables used for Gages ; Chr = defines the Character used to draw with X VAR Byte ' X = Drawing position Y VAR Byte ' Y = Drawing position Xc CON 12 'Constants used for Gages ; Xc = X Center Yc CON 6 ' ; Yc = Y Center Xs CON 12 ' ; Xs = X Size Note: The X Size must be twice the Y Size in order to resemble a circle Ys CON 6 ' ; Ys = Y Size because of the aspect ratio of the characters displayed on the screen. ' ' MCTL - Mode control register ' +---------------------------------------+ ' ¦ D7 ¦ D6 ¦ D5 ¦ D4 ¦ D3 ¦ D2 ¦ D1 ¦ D0 ¦ ' +----+----+----+----+----+----+----+----¦ ' ¦ -- ¦DRPD¦SPI3¦STON¦GLVL¦GLVL¦MODE¦MODE¦ ' +---------------------------------------+ ' ' ' D7 - don't care 0 ' ' D6(DRPD) - DATA ready status 0 - OUTPUT TO INT1 PIN ' 1 - is NOT OUTPUT TO INT1 PIN ' ' D5(SPI3W)- Wire Mode 0 - SPI is 4-wire mode ' 1 - SPI is 3-wire mode ' ' D4(STON) - Self Test 0 - NOT enabled ' 1 - enabled ' ' D3(GLVL[1]) - g-SELECT 00 - 8g ; 16 LSB/g in 8-Bit format ' D2(GLVL[0]) - g-SELECT 10 - 4g ; 32 LSB/g in 8-Bit format ' 01 - 2g ; 64 LSB/g in 8-Bit format ' ' ; Note: When reading g in 10-Bit ' ; format, resolution is fixed ' ; at 64 LSB/g ' 10-Bit g register ' +-------------------------------------------------+ ' ¦ D9 ¦ D8 ¦ D7 ¦ D6 ¦ D5 ¦ D4 ¦ D3 ¦ D2 ¦ D1 ¦ D0 ¦ ' +-------------------------------------------------+ ' ¦<------------------------------------->¦ ; These 8 bits are READ in 8g mode ' ¦<------------------------------------->¦ ; These 8 bits are READ in 4g mode ' ¦<------------------------------------->¦ ; These 8 bits are READ in 2g mode ' ' D1(MODE[1]) - Mode SELECT 00 - Standby ' D0(MODE[0]) - Mode SELECT 01 - Measurement ' 10 - Level Detection ' 11 - Pulse Detection Main: Address = MCTL: SendData = %01100101: GOSUB DataOut 'Set the Mode control register 'DATA ready status is NOT OUTPUT TO INT1 PIN '3-wire SPI mode 'Self Test NOT enabled '+/-2g sensitivity mode 'Measurement mode Address = XOFFL: SendData = XCal& $FF: GOSUB DataOut 'Write X-Axis Calibration Value ; LOWBYTE Address = XOFFH: SendData = XCal >> 8: GOSUB DataOut ' ; HIGHBYTE Address = YOFFL: SendData = YCal& $FF: GOSUB DataOut 'Write Y-Axis Calibration Value ; LOWBYTE Address = YOFFH: SendData = YCal >> 8: GOSUB DataOut ' ; HIGHBYTE Address = ZOFFL: SendData = ZCal& $FF: GOSUB DataOut 'Write Z-Axis Calibration Value ; LOWBYTE Address = ZOFFH: SendData = ZCal >> 8: GOSUB DataOut ' ; HIGHBYTE DEBUG CLS 'Clear Display GOSUB TextField 'Draw TEXT field (stationary TEXT that does not get updated) GOSUB DrawGages 'Draw the Gages used for X,Y, and Z rotation indicators ReadDataLoop: Address = XOUT8:GOSUB DataIn 'Read in X-Axis Acceleration Value XAccel = ReceiveData|($FF00*ReceiveData.BIT7) 'Sign extend the two's complement byte so 'negative numbers can be properly displayed Address = YOUT8:GOSUB DataIn 'Read in Y-Axis Acceleration Value YAccel = ReceiveData|($FF00*ReceiveData.BIT7) 'Sign extend the two's complement byte so 'negative numbers can be properly displayed Address = ZOUT8:GOSUB DataIn 'Read in Z-Axis Acceleration Value ZAccel = ReceiveData|($FF00*ReceiveData.BIT7) 'Sign extend the two's complement byte so 'negative numbers can be properly displayed Xrot = YAccel ATN ZAccel 'Calculate and Display X_Rotation DEBUG CRSRXY,38,10,DEC (Xrot*45)/32," " IF OldXrot<>Xrot THEN 'No sense redrawing needle if nothing has changed Temp1 = OldXrot: Chr = 32:Temp3 = 6:GOSUB DrawNeedle 'First Blank-out Old Needle position Temp1 = Xrot : Chr = 42:Temp3 = 6:GOSUB DrawNeedle 'Then Re-draw New Needle position OldXrot = Xrot ENDIF Yrot = ZAccel ATN XAccel 'Calculate and Display Y_Rotation DEBUG CRSRXY,38,23,DEC (Yrot*45)/32," " IF OldYrot<>Yrot THEN 'No sense redrawing needle if nothing has changed Temp1 = OldYrot: Chr = 32:Temp3 = 19:GOSUB DrawNeedle 'First Blank-out Old Needle position Temp1 = Yrot : Chr = 42:Temp3 = 19:GOSUB DrawNeedle 'Then Re-draw New Needle position OldYrot = Yrot ENDIF Zrot = XAccel ATN YAccel 'Calculate and Display Z_Rotation DEBUG CRSRXY,38,36,DEC (Zrot*45)/32," " 'down's z IF OldZrot<>Zrot THEN 'No sense redrawing needle if nothing has changed Temp1 = OldZrot: Chr = 32:Temp3 = 32:GOSUB DrawNeedle 'First Blank-out Old Needle position Temp1 = Zrot : Chr = 42:Temp3 = 32:GOSUB DrawNeedle 'Then Re-draw New Needle position OldZrot = Zrot ENDIF DEBUG CRSRXY,50,3, SDEC XAccel, " ", 'Display the RAW X, Y, and Z Accelerometer values up CRSRXY,50,4, SDEC YAccel, " ", CRSRXY,50,5, SDEC ZAccel, " " GOTO ReadDataLoop DataOut: LOW CSPin 'Pull chip select pin low to start transmission SHIFTOUT DATAPin, CLKPin, MSBFIRST, [(Address|%1000000)<<1] 'Select register Address SHIFTOUT DATAPin, CLKPin, MSBFIRST, [SendData] 'Write value to Address HIGH CSPin 'End transmission RETURN DataIn: LOW CSPin 'Pull chip select pin low to start transmission SHIFTOUT DATAPin, CLKPin, MSBFIRST, [Address<<1] 'Select register Address SHIFTIN DATAPin, CLKPin, MSBPRE, [ReceiveData] 'Read value from Address HIGH CSPin 'End transmission RETURN TextField: DEBUG CRSRXY,40,0,"MMA7455 3-Axis Accelerometer BS2 DEMO #2", 'Display all stationary TEXT that does not get updated CRSRXY,48,2,"8-Bit 2g Mode ; 64 LSB/g", CRSRXY,25,10,"X_Rotation = ", CRSRXY,25,23,"Y_Rotation = ", CRSRXY,25,36,"Z_Rotation = ", CRSRXY,48,3, "X=", CRSRXY,48,4, "Y=", CRSRXY,48,5, "Z=" RETURN DrawGages: 'Use Sine/Cosine method to draw circles to be used as gages FOR Temp1 = 0 TO 255 STEP 5 X = SIN(Temp1) 'Get Sine value from Binary RAD IF X>128 THEN X=255-X 'Handles negative numbers for graphing data X = Xc - ((X* Xs)/ 128) ELSE X = Xc + ((X* Xs)/ 128) 'Handles positive numbers for graphing data ENDIF Y = COS(Temp1) 'Get CoSine value from Binary RAD IF Y>128 THEN Y=255-Y 'Handles negative numbers for graphing data Y = Yc - ((Y* Ys)/ 128) ELSE Y = Yc + ((Y* Ys)/ 128) 'Handles positive numbers for graphing data ENDIF DEBUG CRSRXY,X,Y,46 'Draw all three gages at once 3­Ó¹Ï DEBUG CRSRXY,X,Y+13,46 DEBUG CRSRXY,X,Y+26,46 NEXT DEBUG CRSRXY,Xc,Yc,42 'Draw Center of all three gages (Fixed point) ¹Ï¤º­ìÂI DEBUG CRSRXY,Xc,Yc+13,42 DEBUG CRSRXY,Xc,Yc+26,42 RETURN DrawNeedle: FOR Temp2 = 1 TO 2 'Use a derivative of the Sine/Cosine Circle method to draw gage needles X = SIN(Temp1+64) 'Add 90 Deg to Binary Radian and Get Sine value IF X>128 THEN X=255-X X = Xc - ((X* (Xs*Temp2)/3)/ 128) 'Handles negative numbers for graphing data ELSE X = Xc + ((X* (Xs*Temp2)/3)/ 128) 'Handles positive numbers for graphing data ENDIF Y = COS(Temp1+64) 'Add 90 Deg to Binary Radian and Get CoSine value IF Y>128 THEN Y=255-Y Y = Temp3 - ((Y* (Ys*Temp2)/3)/ 128) 'Handles negative numbers for graphing data ELSE Y = Temp3 + ((Y* (Ys*Temp2)/3)/ 128) 'Handles negative numbers for graphing data ENDIF DEBUG CRSRXY,X,Y,Chr 'Display Needle by drawing points from the center of the gage out NEXT RETURN