TMC2130Stepper

Beaglebone library for Trinamic TMC2130 Stepper driver in C++ and Python.
Library is depeprecated and has been replaced with TMCStepper. This library might as well work on beaglebone.

TODO:

• The SPIO x-pin can be used via 0xFFFFFFFF but a 2 is returned.

Installation:

Login to beaglebone with for example SSH. Git clone this repository to the command line

git clone --recurse-submodules https://github.com/hstarmans/TMC2130Stepper.git

Install cmake

sudo apt -y install cmake

Library can be installed via python.

sudo pip3 install ./TMC2130Stepper

SPI requires elevated privileges or you should add yourself to the dialout group.

Compile notes

Beaglebone

cmake -H. -Bbuild & make -C ./build

Cross compiler

Cross compiler can be downloaded from link. Ensure the cross-compiler matches the target system;

gcc -version

You will need to download both the cross-compiler and the target root-file system. If all is setup correctly, you should be able to run. Make sure the toolchain is pointed to correct directory.

cmake -H. -Bbuild -DCMAKE_TOOLCHAIN_FILE=Toolchain-bb.cmake & make -C ./build

Remove build if a cmake fails.

Examples

Made a couple of examples for the Firestarter v2 board. This was mainly done to test the code. Better examples can be found at the original library of teemuatlut. The command map_gpio is run internally to map the pins. So pass all the pins even if they are not used in the object. Elevated privileges, i.e. sudo, can be required.

What works:

Nearly all the features in the registeries are configurable through get/set functions. See below for a list of functions. Datasheet (link) from Trinamic also provides further detail into the settings available.

Current calculations

A simple way to set the current is to use the setCurrent() method.

I_rms = (CS+1)/32 * V_fs/(R_sense+0.02mOhm) * 1/sqrt(2)
I_motor = I_sine/248 * (CS+1/32) * V_fs/(R_sense+0.02mOhm)

Where:
I_rms is the rms current
I_motor is the motor current
CS is the Current Scale value
V_fs is the voltage determined by v_sense
R_sense is the chosen sense resistor
I_sine is the current position in the sine table. I_motor reaches peak value at I_sine = 248

If external_ref is enabled, V_fs is scaled by V_ain/2.5V

Functions

Function	Argument range	Returns	Description
begin	-	-	Initialized pins Enable, Direction, Step and Chip Select. Initialized the SPI pins MOSI, MISO and SCK. Calls spi.begin() Sets off_time = 2 and blank_time = 24
setCurrent	0..2000 0.1 .. 1 0..1	-	Helper function to set the motor RMS current. Arguments: uint16_t Desired current in milliamps float Sense resistor value float Multiplier for holding current Example for SilentStepStick2130: setCurrent(1200, 0.11, 0.5) Makes use of the run_current() and hold_current() funtions.
SilentStepStick2130	0..2000	-	Calls the begin() functions and according to the argument sets the current with sense resistor being 0.11 and multiplier being 0.5

Register functions:

Note: You can read the saved value by calling a function without providing an argument.

GCONF register

Function	Argument range	Returns	Description
GCONF	-	uint32_t	Read actual bits from the register
external_ref	0/1	bool	Use external voltage reference for coil currents
internal_sense_R	0/1	bool	Use internal sense resistors
stealthChop	0/1	bool	Enable stealthChop (dependant on velocity thresholds)
commutation	0/1	bool	Enable commutation by full step encoder
shaft_dir	0/1	bool	Inverse motor direction
diag0_errors	0/1	bool	Enable DIAG0 active on driver errors: Over temperature (ot), short to GND (s2g), undervoltage chargepump (uv_cp)
diag0_temp_prewarn	0/1	bool	Enable DIAG0 active on driver over temperature prewarning
diag0_stall	0/1	bool	Enable DIAG0 active on motor stall (set TCOOLTHRS before using this feature)
diag1_stall	0/1	bool	Enable DIAG1 active on motor stall (set TCOOLTHRS before using this feature)
diag1_index	0/1	bool	Enable DIAG1 active on index position (microstep look up table position 0)
diag1_chopper_on	0/1	bool	Enable DIAG1 active when chopper is on
diag1_steps_skipped	0/1	bool	Enable output toggle when steps are skipped in dcStep mode (increment of LOST_STEPS). Do not enable in conjunction with other DIAG1 options.
diag0_active_high	0/1	bool	Set DIAG0 to active high
diag1_active_high	0/1	bool	Set DIAG1 to active high
small_hysteresis	0/1	bool	0: Hysteresis for step frequency comparison is 1/16 1: Hysteresis for step frequency comparison is 1/32
stop_enable	0/1	bool	Emergency stop: DCIN stops the sequencer when tied high (no steps become executed by the sequencer, motor goes to standstill state).
direct_mode	0/1	bool	Motor coil currents and polarity are directly controlled by the SPI interface.

IHOLD_IRUN register

Function	Argument	Returns	Description
hold_current	0..31	uint8_t	Standstill current (0=1/32…31=32/32)
run_current	0..31	uint8_t	Motor run current (0=1/32…31=32/32)
hold_delay	0..15	uint8_t	Controls the number of clock cycles for motor power down after a motion as soon as standstill is detected (stst=1) and TPOWERDOWN has expired.

REG_TPOWERDOWN register

Function	Argument	Returns	Description
power_down_delay	0..255	uint8_t	power_down_delay sets the delay time after stand still (stst) of the motor to motor current power down. Time range is about 0 to 4 seconds. 0…((2^8)-1) * 2^18 tCLK

REG_TSTEP register

Function	Argument	Returns	Description
microstep_time	-	uint32_t	Read the actual measured time between two 1/256 microsteps derived from the step input frequency in units of 1/fCLK.

REG_TPWMTHRS register

Function	Argument	Returns	Description
stealth_max_speed	0..1,048,575	uint32_t	This is the upper velocity for stealthChop voltage PWM mode. TSTEP ≥ TPWMTHRS - stealthChop PWM mode is enabled, if configured - dcStep is disabled

REG_TCOOLTHRS register

Function	Argument	Returns	Description
coolstep_min_speed	0..1,048,575	uint32_t	This is the lower threshold velocity for switching on smart energy coolStep and stallGuard feature.

REG_THIGH register

Function	Argument	Returns	Description
mode_sw_speed	0..1,048,575	uint32_t	This velocity setting allows velocity dependent switching into a different chopper mode and fullstepping to maximize torque.

REG_XDRIRECT register

Function	Argument	Returns	Description
coil_A_current	-255..+255	int16_t	Specifies Motor coil currents and polarity directly programmed via the serial interface. In this mode, the current is scaled by IHOLD setting.
coil_B_current	-255..+255	int16_t	As above.

REG_VDCMIN register

Function	Argument	Returns	Description
DCstep_min_speed	0..8,388,607	uint32_t	The automatic commutation dcStep becomes enabled by the external signal DCEN. VDCMIN is used as the minimum step velocity when the motor is heavily loaded. Hint: Also set DCCTRL parameters in order to operate dcStep.

REG_CHOPCONF register

Function	Argument	Returns	Description
CHOPCONF	-	uint32_t	Read actual bits from the register
off_time	0..15	uint8_t	Off time setting controls duration of slow decay phase NCLK= 12 + 32*TOFF Initialized to value 2 (NCLK = 76) by begin()
hysteresis_start	1..8	uint8_t	Add 1, 2, …, 8 to hysteresis low value HEND (1/512 of this setting adds to current setting) Attention: Effective HEND+HSTRT ≤ 16. Hint: Hysteresis decrement is done each 16 clocks
fast_decay_time	0..15	uint8_t	Fast decay time setting TFD with NCLK= 32*HSTRT
hysteresis_end	-3..12	int8_t	This is the hysteresis value which becomes used for the hysteresis chopper.
sine_offset	-3..12	int8_t	This is the sine wave offset and 1/512 of the value becomes added to the absolute value of each sine wave entry.
disable_I_comparator	0/1	bool	1: Disables current comparator usage for termination of the fast decay cycle. chopper_mode needs to be 1.
random_off_time	0/1	bool	0: Chopper off time is fixed as set by TOFF 1: Random mode, TOFF is random modulated by dNCLK= -12 … +3 clocks.
chopper_mode	0/1	uint8_t	0: Standard mode (spreadCycle) 1: Constant off time with fast decay time. Fast decay time is also terminated when the negative nominal current is reached. Fast decay is after on time.
blank_time	16, 24, 36, 54	uint8_t	Set comparator blank time to 16, 24, 36 or 54 clocks. Hint: 24 or 36 is recommended for most applications Initialized to 36 (register value = 3) by begin()
high_sense_R	0/1	bool	0: Low sensitivity, high sense resistor voltage 1: High sensitivity, low sense resistor voltage
fullstep_threshold	0/1	bool	This bit enables switching to fullstep, when VHIGH is exceeded. Switching takes place only at 45° position. The fullstep target current uses the current value from the microstep table at the 45° position.
high_speed_mode	0/1	bool	This bit enables switching to chm=1 and fd=0, when VHIGH is exceeded. This way, a higher velocity can be achieved. Can be combined with vhighfs=1. If set, the TOFF setting automatically becomes doubled during high velocity operation in order to avoid doubling of the chopper frequency.
sync_phases	0..15	bool	Synchronization of the chopper for both phases of a two phase motor in order to avoid the occurrence of a beat, especially at low motor velocities. It is automatically switched off above VHIGH.
microsteps	255, 128, 64, 32, 16, 8, 4, 2, 0 (FULLSTEP)	uint8_t	Reduced microstep resolution for Step/Dir operation. The resolution gives the number of microstep entries per sine quarter wave.
interpolate	0/1	bool	The actual microstep resolution becomes extrapolated to 256 microsteps for smoothest motor operation.
double_edge_step	0/1	bool	Enable step impulse at each step edge to reduce step frequency requirement.
disable_short_protection	0/1	bool	0: Short to GND protection is on 1: Short to GND protection is disabled

REG_COOLCONF register

Function	Argument	Returns	Description
COOLCONF	-	uint32_t	Read actual bits from the register
sg_min	0..15	uint8_t	If the stallGuard2 result falls below sg_min*32, the motor current becomes increased to reduce motor load angle.
sg_max	0..15	uint8_t	If the stallGuard2 result is equal to or above (sg_min+sg_max+1)*32, the motor current becomes decreased to save energy.
sg_step_width	1, 2, 4, 8	uint8_t	Current increment steps per measured stallGuard2 value
sg_current_decrease	1, 2, 8, 32	uint8_t	For each (value) stallGuard2 values decrease by one
smart_min_current	uint8_t	uint8_t	0: 1/2 of current setting (IRUN) 1: 1/4 of current setting (IRUN)
sg_stall_value	int8_t	int8_t	This signed value controls stallGuard2 level for stall output and sets the optimum measurement range for readout. A lower value gives a higher sensitivity. Zero is the starting value working with most motors. -64 to +63: A higher value makes stallGuard2 less sensitive and requires more torque to indicate a stall.
sg_filter	uint8_t	uint8_t	0: Standard mode, high time resolution for stallGuard2 1: Filtered mode, stallGuard2 signal updated for each four fullsteps (resp. six fullsteps for 3 phase motor) only to compensate for motor pole tolerances

REG_PWMCONF register

Function	Argument	Returns	Description
PWMCONF	-	uint32_t	Read actual bits from the register
stealth_amplitude	0..255	uint8_t	pwm_ autoscale=0 User defined PWM amplitude offset (0-255) The resulting amplitude (limited to 0…255) is: PWM_AMPL + PWM_GRAD * 256 / TSTEP pwm_ autoscale=1 User defined maximum PWM amplitude when switching back from current chopper mode to voltage PWM mode (switch over velocity defined by TPWMTHRS). Do not set too low values, as the regulation cannot measure the current when the actual PWM value goes below a setting specific value. Settings above 0x40 recommended.
stealth_gradient	0..255	uint8_t	pwm_ autoscale=0 Velocity dependent gradient for PWM amplitude: PWM_GRAD * 256 / TSTEP is added to PWM_AMPL pwm_ autoscale=1 User defined maximum PWM amplitude change per half wave (1 to 15)
stealth_freq	0..3	uint8_t	0: fPWM=2/1024 fCLK 1: fPWM=2/683 fCLK 2: fPWM=2/512 fCLK 3: fPWM=2/410 fCLK
stealth_autoscale	0/1	bool	0: User defined PWM amplitude. The current settings have no influence. 1: Enable automatic current control Attention: When using a user defined sine wave table, the amplitude of this sine wave table should not be less than 244. Best results are obtained with 247 to 252 as peak values.
stealth_symmetric	0/1	bool	0: The PWM value may change within each PWM cycle (standard mode) 1: A symmetric PWM cycle is enforced
standstill_mode	0..3	uint8_t	Stand still option when motor current setting is zero (I_HOLD=0). 0: Normal operation 1: Freewheeling 2: Coil shorted using LS drivers 3: Coil shorted using HS drivers

REG_DRVSTATUS register

Function	Argument	Returns	Description
DRVSTATUS	-	uint32_t	Read actual bits from the register

REG_PWM_SCALE register

Function	Argument	Returns	Description
PWM_SCALE	-	uint32_t	Read actual bits from the register

REG_ENCM_CTRL register

Function	Argument	Returns	Description
invert_encoder	0/1	bool	Invert encoder inputs
maxspeed	0/1	bool	Ignore Step input. If set, the hold current IHOLD determines the motor current, unless a step source is activated

REG_LOST_STEPS register

Function	Argument	Returns	Description
LOST_STEPS	-	uint32_t	Read actual bits from the register

Read raw registry: