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Diffstat (limited to 'ArduinoAddons/Arduino_1.6.x/libraries/L6470/L6470.cpp')
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1 files changed, 723 insertions, 0 deletions
diff --git a/ArduinoAddons/Arduino_1.6.x/libraries/L6470/L6470.cpp b/ArduinoAddons/Arduino_1.6.x/libraries/L6470/L6470.cpp new file mode 100755 index 000000000..8278c19ae --- /dev/null +++ b/ArduinoAddons/Arduino_1.6.x/libraries/L6470/L6470.cpp @@ -0,0 +1,723 @@ +//////////////////////////////////////////////////////////// +//ORIGINAL CODE 12/12/2011- Mike Hord, SparkFun Electronics +//LIBRARY Created by Adam Meyer of bildr Aug 18th 2012 +//Released as MIT license +//////////////////////////////////////////////////////////// + +#include <Arduino.h> +#include "L6470.h" +#include <SPI.h> + +#define ENABLE_RESET_PIN 0 +#define K_VALUE 100 + +L6470::L6470(int SSPin){ + _SSPin = SSPin; + // Serial.begin(9600); +} + +void L6470::init(int k_value){ + // This is the generic initialization function to set up the Arduino to + // communicate with the dSPIN chip. + + // set up the input/output pins for the application. + pinMode(SLAVE_SELECT_PIN, OUTPUT); // The SPI peripheral REQUIRES the hardware SS pin- + // pin 10- to be an output. This is in here just + // in case some future user makes something other + // than pin 10 the SS pin. + + pinMode(_SSPin, OUTPUT); + digitalWrite(_SSPin, HIGH); + pinMode(MOSI, OUTPUT); + pinMode(MISO, INPUT); + pinMode(SCK, OUTPUT); + pinMode(BUSYN, INPUT); +#if (ENABLE_RESET_PIN == 1) + pinMode(RESET, OUTPUT); + // reset the dSPIN chip. This could also be accomplished by + // calling the "L6470::ResetDev()" function after SPI is initialized. + digitalWrite(RESET, HIGH); + delay(10); + digitalWrite(RESET, LOW); + delay(10); + digitalWrite(RESET, HIGH); + delay(10); +#endif + + + // initialize SPI for the dSPIN chip's needs: + // most significant bit first, + // SPI clock not to exceed 5MHz, + // SPI_MODE3 (clock idle high, latch data on rising edge of clock) + SPI.begin(); + SPI.setBitOrder(MSBFIRST); + SPI.setClockDivider(SPI_CLOCK_DIV16); // or 2, 8, 16, 32, 64 + SPI.setDataMode(SPI_MODE3); + + // First things first: let's check communications. The CONFIG register should + // power up to 0x2E88, so we can use that to check the communications. + if (GetParam(CONFIG) == 0x2E88){ + //Serial.println('good to go'); + } + else{ + //Serial.println('Comm issue'); + } + +#if (ENABLE_RESET_PIN == 0) + resetDev(); +#endif + // First, let's set the step mode register: + // - SYNC_EN controls whether the BUSY/SYNC pin reflects the step + // frequency or the BUSY status of the chip. We want it to be the BUSY + // status. + // - STEP_SEL_x is the microstepping rate- we'll go full step. + // - SYNC_SEL_x is the ratio of (micro)steps to toggles on the + // BUSY/SYNC pin (when that pin is used for SYNC). Make it 1:1, despite + // not using that pin. + //SetParam(STEP_MODE, !SYNC_EN | STEP_SEL_1 | SYNC_SEL_1); + + + SetParam(KVAL_RUN, k_value); + SetParam(KVAL_ACC, k_value); + SetParam(KVAL_DEC, k_value); + SetParam(KVAL_HOLD, k_value); + + // Set up the CONFIG register as follows: + // PWM frequency divisor = 1 + // PWM frequency multiplier = 2 (62.5kHz PWM frequency) + // Slew rate is 290V/us + // Do NOT shut down bridges on overcurrent + // Disable motor voltage compensation + // Hard stop on switch low + // 16MHz internal oscillator, nothing on output + SetParam(CONFIG, CONFIG_PWM_DIV_1 | CONFIG_PWM_MUL_2 | CONFIG_SR_290V_us| CONFIG_OC_SD_DISABLE | CONFIG_VS_COMP_DISABLE | CONFIG_SW_HARD_STOP | CONFIG_INT_16MHZ); + // Configure the RUN KVAL. This defines the duty cycle of the PWM of the bridges + // during running. 0xFF means that they are essentially NOT PWMed during run; this + // MAY result in more power being dissipated than you actually need for the task. + // Setting this value too low may result in failure to turn. + // There are ACC, DEC, and HOLD KVAL registers as well; you may need to play with + // those values to get acceptable performance for a given application. + //SetParam(KVAL_RUN, 0xFF); + // Calling GetStatus() clears the UVLO bit in the status register, which is set by + // default on power-up. The driver may not run without that bit cleared by this + // read operation. + getStatus(); + + hardStop(); //engage motors +} + +boolean L6470::isBusy(){ + int status = getStatus(); + return !((status >> 1) & 0b1); +} + +void L6470::setMicroSteps(int microSteps){ + byte stepVal = 0; + + for(stepVal = 0; stepVal < 8; stepVal++){ + if(microSteps == 1) break; + microSteps = microSteps >> 1; + } + + SetParam(STEP_MODE, !SYNC_EN | stepVal | SYNC_SEL_1); +} + +void L6470::setThresholdSpeed(float thresholdSpeed){ + // Configure the FS_SPD register- this is the speed at which the driver ceases + // microstepping and goes to full stepping. FSCalc() converts a value in steps/s + // to a value suitable for this register; to disable full-step switching, you + // can pass 0x3FF to this register. + + if(thresholdSpeed == 0.0){ + SetParam(FS_SPD, 0x3FF); + } + else{ + SetParam(FS_SPD, FSCalc(thresholdSpeed)); + } +} + + +void L6470::setCurrent(int current){} + + + +void L6470::setMaxSpeed(int speed){ + // Configure the MAX_SPEED register- this is the maximum number of (micro)steps per + // second allowed. You'll want to mess around with your desired application to see + // how far you can push it before the motor starts to slip. The ACTUAL parameter + // passed to this function is in steps/tick; MaxSpdCalc() will convert a number of + // steps/s into an appropriate value for this function. Note that for any move or + // goto type function where no speed is specified, this value will be used. + SetParam(MAX_SPEED, MaxSpdCalc(speed)); +} + + +void L6470::setMinSpeed(int speed){ + // Configure the MAX_SPEED register- this is the maximum number of (micro)steps per + // second allowed. You'll want to mess around with your desired application to see + // how far you can push it before the motor starts to slip. The ACTUAL parameter + // passed to this function is in steps/tick; MaxSpdCalc() will convert a number of + // steps/s into an appropriate value for this function. Note that for any move or + // goto type function where no speed is specified, this value will be used. + SetParam(MIN_SPEED, MinSpdCalc(speed)); +} + + + + +void L6470::setAcc(float acceleration){ + // Configure the acceleration rate, in steps/tick/tick. There is also a DEC register; + // both of them have a function (AccCalc() and DecCalc() respectively) that convert + // from steps/s/s into the appropriate value for the register. Writing ACC to 0xfff + // sets the acceleration and deceleration to 'infinite' (or as near as the driver can + // manage). If ACC is set to 0xfff, DEC is ignored. To get infinite deceleration + // without infinite acceleration, only hard stop will work. + unsigned long accelerationBYTES = AccCalc(acceleration); + SetParam(ACC, accelerationBYTES); +} + + +void L6470::setDec(float deceleration){ + unsigned long decelerationBYTES = DecCalc(deceleration); + SetParam(DEC, decelerationBYTES); +} + + +long L6470::getPos(){ + unsigned long position = GetParam(ABS_POS); + return convert(position); +} + +float L6470::getSpeed(){ + /* + SPEED + The SPEED register contains the current motor speed, expressed in step/tick (format unsigned fixed point 0.28). + In order to convert the SPEED value in step/s the following formula can be used: + Equation 4 + where SPEED is the integer number stored into the register and tick is 250 ns. + The available range is from 0 to 15625 step/s with a resolution of 0.015 step/s. + Note: The range effectively available to the user is limited by the MAX_SPEED parameter. + */ + + return (float) GetParam(SPEED); + //return (float) speed * pow(8, -22); + //return FSCalc(speed); NEEDS FIX +} + + +void L6470::setOverCurrent(unsigned int ma_current){ + // Configure the overcurrent detection threshold. + byte OCValue = floor(ma_current / 375); + if(OCValue > 0x0F)OCValue = 0x0F; + SetParam(OCD_TH, OCValue); +} + +void L6470::setStallCurrent(float ma_current){ + byte STHValue = (byte)floor(ma_current / 31.25); + if(STHValue > 0x80)STHValue = 0x80; + if(STHValue < 0)STHValue = 0; + SetParam(STALL_TH, STHValue); +} + +void L6470::SetLowSpeedOpt(boolean enable){ + // Enable or disable the low-speed optimization option. If enabling, + // the other 12 bits of the register will be automatically zero. + // When disabling, the value will have to be explicitly written by + // the user with a SetParam() call. See the datasheet for further + // information about low-speed optimization. + Xfer(SET_PARAM | MIN_SPEED); + if (enable) Param(0x1000, 13); + else Param(0, 13); +} + + +void L6470::run(byte dir, float spd){ + // RUN sets the motor spinning in a direction (defined by the constants + // FWD and REV). Maximum speed and minimum speed are defined + // by the MAX_SPEED and MIN_SPEED registers; exceeding the FS_SPD value + // will switch the device into full-step mode. + // The SpdCalc() function is provided to convert steps/s values into + // appropriate integer values for this function. + unsigned long speedVal = SpdCalc(spd); + + Xfer(RUN | dir); + if (speedVal > 0xFFFFF) speedVal = 0xFFFFF; + Xfer((byte)(speedVal >> 16)); + Xfer((byte)(speedVal >> 8)); + Xfer((byte)(speedVal)); +} + + +void L6470::Step_Clock(byte dir){ + // STEP_CLOCK puts the device in external step clocking mode. When active, + // pin 25, STCK, becomes the step clock for the device, and steps it in + // the direction (set by the FWD and REV constants) imposed by the call + // of this function. Motion commands (RUN, MOVE, etc) will cause the device + // to exit step clocking mode. + Xfer(STEP_CLOCK | dir); +} + +void L6470::move(long n_step){ + // MOVE will send the motor n_step steps (size based on step mode) in the + // direction imposed by dir (FWD or REV constants may be used). The motor + // will accelerate according the acceleration and deceleration curves, and + // will run at MAX_SPEED. Stepping mode will adhere to FS_SPD value, as well. + + byte dir; + + if(n_step >= 0){ + dir = FWD; + } + else{ + dir = REV; + } + + long n_stepABS = abs(n_step); + + Xfer(MOVE | dir); //set direction + if (n_stepABS > 0x3FFFFF) n_step = 0x3FFFFF; + Xfer((byte)(n_stepABS >> 16)); + Xfer((byte)(n_stepABS >> 8)); + Xfer((byte)(n_stepABS)); +} + +void L6470::goTo(long pos){ + // GOTO operates much like MOVE, except it produces absolute motion instead + // of relative motion. The motor will be moved to the indicated position + // in the shortest possible fashion. + + Xfer(GOTO); + if (pos > 0x3FFFFF) pos = 0x3FFFFF; + Xfer((byte)(pos >> 16)); + Xfer((byte)(pos >> 8)); + Xfer((byte)(pos)); +} + + +void L6470::goTo_DIR(byte dir, long pos){ + // Same as GOTO, but with user constrained rotational direction. + + Xfer(GOTO_DIR); + if (pos > 0x3FFFFF) pos = 0x3FFFFF; + Xfer((byte)(pos >> 16)); + Xfer((byte)(pos >> 8)); + Xfer((byte)(pos)); +} + +void L6470::goUntil(byte act, byte dir, unsigned long spd){ + // GoUntil will set the motor running with direction dir (REV or + // FWD) until a falling edge is detected on the SW pin. Depending + // on bit SW_MODE in CONFIG, either a hard stop or a soft stop is + // performed at the falling edge, and depending on the value of + // act (either RESET or COPY) the value in the ABS_POS register is + // either RESET to 0 or COPY-ed into the MARK register. + Xfer(GO_UNTIL | act | dir); + if (spd > 0x3FFFFF) spd = 0x3FFFFF; + Xfer((byte)(spd >> 16)); + Xfer((byte)(spd >> 8)); + Xfer((byte)(spd)); +} + +void L6470::releaseSW(byte act, byte dir){ + // Similar in nature to GoUntil, ReleaseSW produces motion at the + // higher of two speeds: the value in MIN_SPEED or 5 steps/s. + // The motor continues to run at this speed until a rising edge + // is detected on the switch input, then a hard stop is performed + // and the ABS_POS register is either COPY-ed into MARK or RESET to + // 0, depending on whether RESET or COPY was passed to the function + // for act. + Xfer(RELEASE_SW | act | dir); +} + +void L6470::goHome(){ + // GoHome is equivalent to GoTo(0), but requires less time to send. + // Note that no direction is provided; motion occurs through shortest + // path. If a direction is required, use GoTo_DIR(). + Xfer(GO_HOME); +} + +void L6470::goMark(){ + // GoMark is equivalent to GoTo(MARK), but requires less time to send. + // Note that no direction is provided; motion occurs through shortest + // path. If a direction is required, use GoTo_DIR(). + Xfer(GO_MARK); +} + + +void L6470::setMark(long value){ + + Xfer(MARK); + if (value > 0x3FFFFF) value = 0x3FFFFF; + if (value < -0x3FFFFF) value = -0x3FFFFF; + + + Xfer((byte)(value >> 16)); + Xfer((byte)(value >> 8)); + Xfer((byte)(value)); +} + + +void L6470::setMark(){ + long value = getPos(); + + Xfer(MARK); + if (value > 0x3FFFFF) value = 0x3FFFFF; + if (value < -0x3FFFFF) value = -0x3FFFFF; + + + Xfer((byte)(value >> 16)); + Xfer((byte)(value >> 8)); + Xfer((byte)(value)); +} + +void L6470::setAsHome(){ + // Sets the ABS_POS register to 0, effectively declaring the current + // position to be "HOME". + Xfer(RESET_POS); +} + +void L6470::resetDev(){ + // Reset device to power up conditions. Equivalent to toggling the STBY + // pin or cycling power. + Xfer(RESET_DEVICE); +} + +void L6470::softStop(){ + // Bring the motor to a halt using the deceleration curve. + Xfer(SOFT_STOP); +} + +void L6470::hardStop(){ + // Stop the motor right away. No deceleration. + Xfer(HARD_STOP); +} + +void L6470::softFree(){ + // Decelerate the motor and disengage + Xfer(SOFT_HIZ); +} + +void L6470::free(){ + // disengage the motor immediately with no deceleration. + Xfer(HARD_HIZ); +} + +int L6470::getStatus(){ + // Fetch and return the 16-bit value in the STATUS register. Resets + // any warning flags and exits any error states. Using GetParam() + // to read STATUS does not clear these values. + int temp = 0; + Xfer(GET_STATUS); + temp = Xfer(0)<<8; + temp |= Xfer(0); + return temp; +} + +unsigned long L6470::AccCalc(float stepsPerSecPerSec){ + // The value in the ACC register is [(steps/s/s)*(tick^2)]/(2^-40) where tick is + // 250ns (datasheet value)- 0x08A on boot. + // Multiply desired steps/s/s by .137438 to get an appropriate value for this register. + // This is a 12-bit value, so we need to make sure the value is at or below 0xFFF. + float temp = stepsPerSecPerSec * 0.137438; + if( (unsigned long) long(temp) > 0x00000FFF) return 0x00000FFF; + else return (unsigned long) long(temp); +} + + +unsigned long L6470::DecCalc(float stepsPerSecPerSec){ + // The calculation for DEC is the same as for ACC. Value is 0x08A on boot. + // This is a 12-bit value, so we need to make sure the value is at or below 0xFFF. + float temp = stepsPerSecPerSec * 0.137438; + if( (unsigned long) long(temp) > 0x00000FFF) return 0x00000FFF; + else return (unsigned long) long(temp); +} + +unsigned long L6470::MaxSpdCalc(float stepsPerSec){ + // The value in the MAX_SPD register is [(steps/s)*(tick)]/(2^-18) where tick is + // 250ns (datasheet value)- 0x041 on boot. + // Multiply desired steps/s by .065536 to get an appropriate value for this register + // This is a 10-bit value, so we need to make sure it remains at or below 0x3FF + float temp = stepsPerSec * .065536; + if( (unsigned long) long(temp) > 0x000003FF) return 0x000003FF; + else return (unsigned long) long(temp); +} + +unsigned long L6470::MinSpdCalc(float stepsPerSec){ + // The value in the MIN_SPD register is [(steps/s)*(tick)]/(2^-24) where tick is + // 250ns (datasheet value)- 0x000 on boot. + // Multiply desired steps/s by 4.1943 to get an appropriate value for this register + // This is a 12-bit value, so we need to make sure the value is at or below 0xFFF. + float temp = stepsPerSec * 4.1943; + if( (unsigned long) long(temp) > 0x00000FFF) return 0x00000FFF; + else return (unsigned long) long(temp); +} + +unsigned long L6470::FSCalc(float stepsPerSec){ + // The value in the FS_SPD register is ([(steps/s)*(tick)]/(2^-18))-0.5 where tick is + // 250ns (datasheet value)- 0x027 on boot. + // Multiply desired steps/s by .065536 and subtract .5 to get an appropriate value for this register + // This is a 10-bit value, so we need to make sure the value is at or below 0x3FF. + float temp = (stepsPerSec * .065536)-.5; + if( (unsigned long) long(temp) > 0x000003FF) return 0x000003FF; + else return (unsigned long) long(temp); +} + +unsigned long L6470::IntSpdCalc(float stepsPerSec){ + // The value in the INT_SPD register is [(steps/s)*(tick)]/(2^-24) where tick is + // 250ns (datasheet value)- 0x408 on boot. + // Multiply desired steps/s by 4.1943 to get an appropriate value for this register + // This is a 14-bit value, so we need to make sure the value is at or below 0x3FFF. + float temp = stepsPerSec * 4.1943; + if( (unsigned long) long(temp) > 0x00003FFF) return 0x00003FFF; + else return (unsigned long) long(temp); +} + +unsigned long L6470::SpdCalc(float stepsPerSec){ + // When issuing RUN command, the 20-bit speed is [(steps/s)*(tick)]/(2^-28) where tick is + // 250ns (datasheet value). + // Multiply desired steps/s by 67.106 to get an appropriate value for this register + // This is a 20-bit value, so we need to make sure the value is at or below 0xFFFFF. + + float temp = stepsPerSec * 67.106; + if( (unsigned long) long(temp) > 0x000FFFFF) return 0x000FFFFF; + else return (unsigned long)temp; +} + +unsigned long L6470::Param(unsigned long value, byte bit_len){ + // Generalization of the subsections of the register read/write functionality. + // We want the end user to just write the value without worrying about length, + // so we pass a bit length parameter from the calling function. + unsigned long ret_val=0; // We'll return this to generalize this function + // for both read and write of registers. + byte byte_len = bit_len/8; // How many BYTES do we have? + if (bit_len%8 > 0) byte_len++; // Make sure not to lose any partial byte values. + // Let's make sure our value has no spurious bits set, and if the value was too + // high, max it out. + unsigned long mask = 0xffffffff >> (32-bit_len); + if (value > mask) value = mask; + // The following three if statements handle the various possible byte length + // transfers- it'll be no less than 1 but no more than 3 bytes of data. + // L6470::Xfer() sends a byte out through SPI and returns a byte received + // over SPI- when calling it, we typecast a shifted version of the masked + // value, then we shift the received value back by the same amount and + // store it until return time. + if (byte_len == 3) { + ret_val |= long(Xfer((byte)(value>>16))) << 16; + //Serial.println(ret_val, HEX); + } + if (byte_len >= 2) { + ret_val |= long(Xfer((byte)(value>>8))) << 8; + //Serial.println(ret_val, HEX); + } + if (byte_len >= 1) { + ret_val |= Xfer((byte)value); + //Serial.println(ret_val, HEX); + } + // Return the received values. Mask off any unnecessary bits, just for + // the sake of thoroughness- we don't EXPECT to see anything outside + // the bit length range but better to be safe than sorry. + return (ret_val & mask); +} + +byte L6470::Xfer(byte data){ + // This simple function shifts a byte out over SPI and receives a byte over + // SPI. Unusually for SPI devices, the dSPIN requires a toggling of the + // CS (slaveSelect) pin after each byte sent. That makes this function + // a bit more reasonable, because we can include more functionality in it. + byte data_out; + digitalWrite(_SSPin,LOW); + // SPI.transfer() both shifts a byte out on the MOSI pin AND receives a + // byte in on the MISO pin. + data_out = SPI.transfer(data); + digitalWrite(_SSPin,HIGH); + return data_out; +} + + + +void L6470::SetParam(byte param, unsigned long value){ + Xfer(SET_PARAM | param); + ParamHandler(param, value); +} + +unsigned long L6470::GetParam(byte param){ + // Realize the "get parameter" function, to read from the various registers in + // the dSPIN chip. + Xfer(GET_PARAM | param); + return ParamHandler(param, 0); +} + +long L6470::convert(unsigned long val){ + //convert 22bit 2s comp to signed long + int MSB = val >> 21; + + val = val << 11; + val = val >> 11; + + if(MSB == 1) val = val | 0b11111111111000000000000000000000; + return val; +} + +unsigned long L6470::ParamHandler(byte param, unsigned long value){ + // Much of the functionality between "get parameter" and "set parameter" is + // very similar, so we deal with that by putting all of it in one function + // here to save memory space and simplify the program. + unsigned long ret_val = 0; // This is a temp for the value to return. + // This switch structure handles the appropriate action for each register. + // This is necessary since not all registers are of the same length, either + // bit-wise or byte-wise, so we want to make sure we mask out any spurious + // bits and do the right number of transfers. That is handled by the dSPIN_Param() + // function, in most cases, but for 1-byte or smaller transfers, we call + // Xfer() directly. + switch (param) + { + // ABS_POS is the current absolute offset from home. It is a 22 bit number expressed + // in two's complement. At power up, this value is 0. It cannot be written when + // the motor is running, but at any other time, it can be updated to change the + // interpreted position of the motor. + case ABS_POS: + ret_val = Param(value, 22); + break; + // EL_POS is the current electrical position in the step generation cycle. It can + // be set when the motor is not in motion. Value is 0 on power up. + case EL_POS: + ret_val = Param(value, 9); + break; + // MARK is a second position other than 0 that the motor can be told to go to. As + // with ABS_POS, it is 22-bit two's complement. Value is 0 on power up. + case MARK: + ret_val = Param(value, 22); + break; + // SPEED contains information about the current speed. It is read-only. It does + // NOT provide direction information. + case SPEED: + ret_val = Param(0, 20); + break; + // ACC and DEC set the acceleration and deceleration rates. Set ACC to 0xFFF + // to get infinite acceleration/decelaeration- there is no way to get infinite + // deceleration w/o infinite acceleration (except the HARD STOP command). + // Cannot be written while motor is running. Both default to 0x08A on power up. + // AccCalc() and DecCalc() functions exist to convert steps/s/s values into + // 12-bit values for these two registers. + case ACC: + ret_val = Param(value, 12); + break; + case DEC: + ret_val = Param(value, 12); + break; + // MAX_SPEED is just what it says- any command which attempts to set the speed + // of the motor above this value will simply cause the motor to turn at this + // speed. Value is 0x041 on power up. + // MaxSpdCalc() function exists to convert steps/s value into a 10-bit value + // for this register. + case MAX_SPEED: + ret_val = Param(value, 10); + break; + // MIN_SPEED controls two things- the activation of the low-speed optimization + // feature and the lowest speed the motor will be allowed to operate at. LSPD_OPT + // is the 13th bit, and when it is set, the minimum allowed speed is automatically + // set to zero. This value is 0 on startup. + // MinSpdCalc() function exists to convert steps/s value into a 12-bit value for this + // register. SetLowSpeedOpt() function exists to enable/disable the optimization feature. + case MIN_SPEED: + ret_val = Param(value, 12); + break; + // FS_SPD register contains a threshold value above which microstepping is disabled + // and the dSPIN operates in full-step mode. Defaults to 0x027 on power up. + // FSCalc() function exists to convert steps/s value into 10-bit integer for this + // register. + case FS_SPD: + ret_val = Param(value, 10); + break; + // KVAL is the maximum voltage of the PWM outputs. These 8-bit values are ratiometric + // representations: 255 for full output voltage, 128 for half, etc. Default is 0x29. + // The implications of different KVAL settings is too complex to dig into here, but + // it will usually work to max the value for RUN, ACC, and DEC. Maxing the value for + // HOLD may result in excessive power dissipation when the motor is not running. + case KVAL_HOLD: + ret_val = Xfer((byte)value); + break; + case KVAL_RUN: + ret_val = Xfer((byte)value); + break; + case KVAL_ACC: + ret_val = Xfer((byte)value); + break; + case KVAL_DEC: + ret_val = Xfer((byte)value); + break; + // INT_SPD, ST_SLP, FN_SLP_ACC and FN_SLP_DEC are all related to the back EMF + // compensation functionality. Please see the datasheet for details of this + // function- it is too complex to discuss here. Default values seem to work + // well enough. + case INT_SPD: + ret_val = Param(value, 14); + break; + case ST_SLP: + ret_val = Xfer((byte)value); + break; + case FN_SLP_ACC: + ret_val = Xfer((byte)value); + break; + case FN_SLP_DEC: + ret_val = Xfer((byte)value); + break; + // K_THERM is motor winding thermal drift compensation. Please see the datasheet + // for full details on operation- the default value should be okay for most users. + case K_THERM: + ret_val = Xfer((byte)value & 0x0F); + break; + // ADC_OUT is a read-only register containing the result of the ADC measurements. + // This is less useful than it sounds; see the datasheet for more information. + case ADC_OUT: + ret_val = Xfer(0); + break; + // Set the overcurrent threshold. Ranges from 375mA to 6A in steps of 375mA. + // A set of defined constants is provided for the user's convenience. Default + // value is 3.375A- 0x08. This is a 4-bit value. + case OCD_TH: + ret_val = Xfer((byte)value & 0x0F); + break; + // Stall current threshold. Defaults to 0x40, or 2.03A. Value is from 31.25mA to + // 4A in 31.25mA steps. This is a 7-bit value. + case STALL_TH: + ret_val = Xfer((byte)value & 0x7F); + break; + // STEP_MODE controls the microstepping settings, as well as the generation of an + // output signal from the dSPIN. Bits 2:0 control the number of microsteps per + // step the part will generate. Bit 7 controls whether the BUSY/SYNC pin outputs + // a BUSY signal or a step synchronization signal. Bits 6:4 control the frequency + // of the output signal relative to the full-step frequency; see datasheet for + // that relationship as it is too complex to reproduce here. + // Most likely, only the microsteps per step value will be needed; there is a set + // of constants provided for ease of use of these values. + case STEP_MODE: + ret_val = Xfer((byte)value); + break; + // ALARM_EN controls which alarms will cause the FLAG pin to fall. A set of constants + // is provided to make this easy to interpret. By default, ALL alarms will trigger the + // FLAG pin. + case ALARM_EN: + ret_val = Xfer((byte)value); + break; + // CONFIG contains some assorted configuration bits and fields. A fairly comprehensive + // set of reasonably self-explanatory constants is provided, but users should refer + // to the datasheet before modifying the contents of this register to be certain they + // understand the implications of their modifications. Value on boot is 0x2E88; this + // can be a useful way to verify proper start up and operation of the dSPIN chip. + case CONFIG: + ret_val = Param(value, 16); + break; + // STATUS contains read-only information about the current condition of the chip. A + // comprehensive set of constants for masking and testing this register is provided, but + // users should refer to the datasheet to ensure that they fully understand each one of + // the bits in the register. + case STATUS: // STATUS is a read-only register + ret_val = Param(0, 16); + break; + default: + ret_val = Xfer((byte)(value)); + break; + } + return ret_val; +} |