CORONA 2S – 3S

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Document date: 01/02/2021

All documents published on previous dates have been invalidated.

CORONA 2S – 3S

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Contents

Page 1 Summary information of Corona XS ………………………………. 3 2 SPI interface signals and pin numbers ………………................ 4 3 SPI interface signals and pin numbers ………......................... 6 4 !!! Important warnings!!! …….…………..………..……………..… 6 5 Setup and setup parameters …………………....……..…..….…… 7 6 Command set …………............................................................. 10 7 Performance parameter identification ………..……………….… 11 8 Program example ……………................................................... 12 9 Homming ……………………………….……………………………….. 15 10 Stepper motor specifications ….............................................. 18 11 Dimensions of the card mounted on the stepper motor …….. 19 12 Order information ……………………………………………………… 19

CORONA 2S – 3S

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1 - Summary Information of CORONA XS CORONA XS is a module that is mounted on a Nema 17 stepper motor and consists of a microstepper driver and a trajectory calculator. It has two separate versions, 2S and 3S respectively. The 2S version features a two phase stepper motor while the 3S version features a three phase stepper motor. The CORONA XS units can be controlled by any MCU with SPI hardware. It can do linear interpolation on four different axes. The number of interpolations determines the number of CORONA XS to be used (e.g. 4 interpolations requires 4 corona XS) and all components connect to a single SPI port of your main processor. If the mechanism belonging to the same axis is to be driven by more than one motor, each of the modules should be given the same names. In that case, additional modules should be connected to the same SPI port. The modules learn their names with software and never forget them. Another quad axis can be controlled using a second SPI port. Modules connected to the same SPI interface must be entirely 2S or entirely 3S versions, and all must be set to the same microtstepper value. The performance of the whole system is determined by the weakest axis. Therefore, the optimal value for acceleration, vmin and vmax parameters are determined by the weakest axis. CORONA XS parameter units: Coordinates : Relative values in microstep form Speed : Microstep/second Acceleration: Microstep/second² CORONA XS moves to the target coordinate using trapezoidal velocity equations and uses relative coordinates.

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2 - SPI Interface Signals and Pin Numbers

There are four signal lines on the SPI Interface, consisting of CLK, DATA, CS/ and Ready.

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Ready (Pin 4)

The Ready signal generated by CORONA XS is The Ready signal generated by CORONA XS is followed by the main processor. If the Ready signal is “0”, it means that the CORONA modules are busy. In this case, you must wait for the Ready signal to become “1” before sending a new command. Otherwise, unwanted results will occur. However, the STP command will create an exception and a STP command can be sent even when the Ready signal is “0” (See home process) by the main processor.

CS/ (Pin 6) The CS/ signal generated by your main processor will say that SPI communication has been initiated. If the CS/ lane is “0”, this means that data will be sent from SPI lane. The CS lane should be made 1 after all bits of 16-bit data is gone. Otherwise, if CS=1 is set before all bits are gone, the reliability of the transmitted data cannot be guaranteed. If the CS lane is constantly kept at 0 state, the system may be affected by electrical noise.

CLK (Pin 5) The CLK signal generated by the main processor guides the Data signal. Normally it waits at “0” and for every data bit, it first increases to “1” then drops down to “0”.

Data (MOSI) (Pin 7) The Data signal generated by the main processor carries data bits to be transmitted in serial format. The first bit that sets off is the MSB bit.

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3 – Power Supply Connections and Technical Specifications Power connection is also done through the connector which has the SPI signals. DC GND and signal GND ends are connected to each other and are connected to the 1, 3, 8, 10 pins on the connector. + DC power connection is done through pins numbered 2 and 9. For CORONA XS to work, a minimum of 12 Volt, 0.2 Amp is required. For optimal performance, 24 Volt is recommended. The power supply must be capable of giving 25% more than the calculated current and is preferably regulated. For example, if 4 CORONA modules are to be used; Calculated current: 4 x 0.2*1.25 = 1 Amp. Thus, the power supply must be DC 24 Volt and at least 1A.

4 – Important Warnings

1 Using voltage higher than 24.5V may cause irreversible damage to the modules.

2 Applying reverse voltage between the positive supply and GND pins causes permanent irreversible damage to the modules.

3 Applying a negative or higher voltage than 3.3 Volt to signal pins even for a short time causes irreversible damage to the modules.

4 Connections to connector pins must be made through a 2x5 ICD (2.54 mm) female connector fitted with a ribbon cable.

5 Each of the pins reserved for Gnd and DC Power Unit must be used.

6 Do not plug or unplug the connector while energized. Do not insert the connector backwards.

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5 – Setup & Setup Parameters

At this stage, you will need the MCU card and power supply that can be sent to the CORONA

XS module via the SPI port.

If you wish to use the mechanisms without using a card with the main processor, and would like to use PC, MAC, Raspberry etc. to directly control the mechanisms, you can purchase the CDM (Corona Demo Master) unit. Warning: Modules need to be installed one by one. Connect one end of the SPI data connector cable to the CORONA XS module and the other end to your MCU card in the correct direction. (Only you can know the correct direction on your MCU card) Set the name of the axis on which the module will be used. (X, Y, Z, E) (Table 1) In order for the mechanism to move towards the home switch, determine whether the motor will turn right or left by looking across from the motor shaft (for 3D printers, determine the direction in which the filament will retract on the motor) (Table 2) Determine how many microsteps this module will be (Table 3) Let’s do the following processes according to the example below. The CORONA 2S module will be used in the Z axis, and in order for the mechanism to hit the zero key, the motor needs to turn right. We will run our motor at nine microsteps. Our aim is to determine the setup parameters and introduce them to the module. With this information we have; From Table 1, 7.Bit = 1, 6th Bit = 0 for Z motor. 5. Bit = 0 will be taken from Table 2. In order for CORONA 2S from Table 3 to operate 8 microsteps, 4.Bit = 0, 3. Bit = 1, 2.Bit = 1, 1.Bit = 0, 0.Bit = 1. If the bits are written in their place, our Setup parameter is found as 10001101, ie 0x8D. From Table 4, parameter identification and storage code (SPS) 0x8F ?? is understood to be. ?? If 0x8D is written in the part, our command will be 0x8F8D. If the power is supplied to the system and the Send (0x8F8D) command is executed, the CORONA 2S module will learn the given parameters permanently. Now, even if you turn the module power off and on, the module remembers these parameters every time.

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You can set up your module with new parameters at any time. The only thing you need to pay attention to is that if you have more than one module, their setup must be done individually. If you connect them all into the SPI port at once, all modules will be set up with the same parameters. The meaning of the 7th and 6th bits of the setup parameter.

Table 1

7 6 Value Explanation

0 0 0x00 Let name be X

0 1 0x40 Let name be Y

1 0 0x80 Let name be Z

1 1 0xC0 Let name be E

The meaning of the 5th bit of the setup parameter

Table 2

In order for the mechanism to hit the zero switch;

5 Value Explanation

0 0x00 Motor needs to turn right

1 0x20 Motor needs to turn left

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The meaning of the 4th, 3rd, 2nd first and zeroth bits of the setup parameter

Table 3

Bits

Value 2S 3S

4 3 2 1 0 Microstep Pulse per revolution

Mikrostep Pulse per revolution

0 0 0 0 0 0x00 1.5 300 1.0 300 0 0 0 0 1 0x01 2.0 400 1.5 450

0 0 0 1 0 0x02 2.5 500 2.0 600

0 0 0 1 1 0x03 3.0 600 2.5 750 0 0 1 0 0 0x04 3.5 700 3.0 900 0 0 1 0 1 0x05 4.0 800 3.5 1050

0 0 1 1 0 0x06 4.5 900 4.0 1200

0 0 1 1 1 0x07 5.0 1000 4.5 1350 0 1 0 0 0 0x08 5.5 1100 5.0 1500 0 1 0 0 1 0x09 6.0 1200 5.5 1650

0 1 0 1 0 0x0A 6.5 1300 6.0 1800

0 1 0 1 1 0x0B 7.0 1400 6.5 1950

0 1 1 0 0 0x0C 7.5 1500 7.0 2100 0 1 1 0 1 0x0D 8.0 1600 7.5 2250 0 1 1 1 0 0x0E 8.5 1700 8.0 2400

0 1 1 1 1 0x0F 9.0 1800 8.5 2550

1 0 0 0 0 0x10 9.5 1900 9.0 2700 1 0 0 0 1 0x11 10.0 2000 9.5 2850 1 0 0 1 0 0x12 10.5 2100 10.0 3000

1 0 0 1 1 0x13 11.0 2200 10.5 3150

1 0 1 0 0 0x14 11.5 2300 11.0 3300 1 0 1 0 1 0x15 12.0 2400 11.5 3450 1 0 1 1 0 0x16 12.5 2500 12.0 3600

1 0 1 1 1 0x17 13.0 2600 12.5 3750

1 1 0 0 0 0x18 15.0 3000 13.0 3900 1 1 0 0 1 0x19 16.0 3200 13.5 4050 1 1 0 1 0 0x1A 17.0 3400 14.0 4200

1 1 0 1 1 0x1B 18.0 3600 14.5 4350

1 1 1 0 0 0x1C 21.0 4200 15.0 4500

1 1 1 0 1 0x1D 23.0 4600 15.5 4650 1 1 1 1 0 0x1E 24.0 4800 16.0 4800 1 1 1 1 1 0x1F 25.0 5000 16.5 4950

For example: For module E, in order for the mechanism to hit the home switch, the 2 phase stepper motor must turn left. Motor will be turn 5 microsteps. Our 8-bit parameter = 0xC0 + 0x20 + 0x07 = 0xE7

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6 – Command Set

Table 4

Hex code Mnemonic Means

Coordinate commands

0x0??? XL 12-bit low component of the X coordinate

0x1??? XH 12-bit high component of the X coordinate

0x2??? YL 12-bit low component of the Y coordinate

0x3??? YH 12-bit high component of the Y coordinate

0x4??? ZL 12-bit low component of the Z coordinate

0x5??? XH 12-bit high component of the Z coordinate

0x6??? EL 12-bit low component of the E coordinate

0x7??? EH 12-bit high component of the E coordinate

Seped & Acceleration commands

0x80?? VXL 8-bit low component for Feed Rate value

0x81?? VXH 8-bit high component for Feed Rate value

0x82?? VNL 8-bit low component for Vmin value

0x83?? VNH 8-bit high component for Vmin value

0x84?? ACL 8-bit low component for Acceleration value

0x85?? ACH 8-bit high component for Acceleration value

Movement Commands

0x86?? GHM Go to home position

0x87?? STP Stop *

0x88?? SSP Move one step

0x89?? STR Begin movement

Parameter identification and storage command

0x8F?? SPS Learn parameters and store

* Stp command terminates the GHM command. It has no effect on other commands.

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7 – Performance Parameter Identification

The mass and friction of the moving parts determine the behaviour of the system and they vary from mechanism to mechanism. The acceleration of the motors and their rotations per minute are affected by this situation.

To find the best behaviour for the whole system, parameters such as; acceleration, Vmin, Vmax need to be experimentally identified. For this experiment, all CORONA XS units need to be active. Since the weakest axis will determine the performance of the system, the values of acceleration, Vmax, and Vmin will be the common parameter of all axes and thus the selected values should be tested to ensure they do not cause problems in all axes (x, y, z, e) In order to test the result of changing any parameter, it is required by x, y, z, e modules to take 100 thousand steps. The first parameter that needs to be identified is the Vmin (Jumping velocity) value. This is the velocity value by which the mechanism in its stationary state can be lifted without losing step. The second parameter to be determined is Feedrate (Vmax) value. For this, a low (100 or 500) acceleration value is chosen first. For Vmax, for example, you give a value of 40000. If the motors rotate smoothly without abnormal sounds, the Vmax value is increased, if there is a problem, the Vmax value is decreased. From this point, Vmin and acceleration values cannot be changed.

After the Vmax value is determined, the acceleration value is increased this time to

test whether the motors accelerate properly. If there is an abnormality in the motor

sounds or if the motors cannot turn and start to vibrate, the acceleration value is

decreased and the experiment is repeated.

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If there is no problem, accelerate and retest. As a result of this experiment, your

approximate acceleration and velocity values will be determined. Since your

mechanism will be negatively affected in practice due to cooling, heating, dusting, etc.,

it will be useful to use lower values than the experimental values in order to avoid

problems.

Vmin and Acceleration values are no longer changed anymore. If the feedrate is to be

changed, only the feedrate (Vmax) is changed. The first job of your software should be

to set the Vmin and Acceleration values at the beginning of the program.

8 – Program example

Write your Send(int data) code which sends 16-bit data in accordance with the flowchart above. The contents of the SPI_Send function will vary based on the hardware of your main processor.

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void Send(int Data)

{ if ((Data & 0x8700)!= 0x8700) while (Ready==0); CS(0); SPI_Send(Data); // !! If the 16th bit of the data is also gone, it will return !! CS(1); // Doing CS=1 when the data is on its way may result in an error. } Send_acceleration(); // sends the acceleration value { Send(0x8500 | ((acceleration>>8) & 0xFF)); Send(0x8400 | (acceleration & 0xFF); } Send_Vmin(); // sends the Vmin value {

Send(0x8200 | ((Vmin>>8) & 0xFF)); Send(0x8300 | (Vmin & 0xFF); } Send_Vmax(int Data); // Sends Feed Rate value {

Send(0x8000 | ((Data>>8) & 0xFF)); Send(0x8100 | (Data & 0xFF); } Send_X(int Data); // Sends the X coordinate {

Send( (0x1000 | ((Data>>12) & 0xFFF)); Send(Data & 0xFFF); } Send_Y(int Data); // Sends the Y coordinate {

Send(0x3000 | ((Data>>12) & 0xFFF)); Send(0x2000 | (Data & 0xFFF); } Send_Z(int Data); // Sends the Z coordinate {

Send(0x5000 | ((Data>>12) & 0xFFF)); Send(0x4000 | (Data & 0xFFF); }

Move(); // Begin movement {

Send(0x8900); }

The coordinates of the movements given in the picture are absolute coordinates. However, it should be noted that the CORONA XS unit uses relative coordinates.

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Firstly, let’s write the X, Y, Z coordinates of the desired movements starting from the coordinate we are at. The coordinates in the figure are defined as absolute. Let’s make a fast move along path number 1 and 5, move at normal speed along path 2, 3, 4, 6, 7, 8, 9, 10. Dx, Dy and Dz define the distance between the target coordinate and the current coordinate (relative).

Hareket numarası X Dx Y Dy Z Dz

0 0 0 0 0 100 0

1 100 100 150 150 50 -50

2 200 100 150 0 50 0

3 100 0 250 100 50 0

4 100 0 150 -100 50 0

5 180 80 -50 -200 200 150

6 250 70 10 60 80 -120

7 220 -30 40 30 70 -10

8 230 10 100 60 55 -25

9 270 40 60 -40 60 5

10 250 -20 10 -50 80 20

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In this case, our sample program will be as follows.

// It is adequate to send the acceleration and Vmin values you obtained through

experimentation once at the start of the program.

Send_acceleration(); Send_Vmin(); ....

…. ; Somehow point 0 is reached.

; Now, we are moving from point 0 to point 1.

Send_X(100); Send_Y(150) ; Send_Z(-50) ; SendVmax(Hızlı); Move(); // Move to the 1st point

Send_X(100); SendVmax(Normal); Move(); // Move to the 2nd point Send_Y(100); Move(); // Move to the 3rd point

Send_Y(-100) ; Move(); // Move to the 4rd point

Send_X(80); Send_Y(-200) ; Send_Z(150) ; SendVmax(Hızlı); Move(); // Move to the 5th point Send_X(70); Send_Y(-60) ; Send_Z(-120) ; Move(); // Move to the 6th point

Send_X(-30); Send_Y(30) ; Send_Z(-10) ; Move(); // Move to the 7th point Send_X(10); Send_Y(60) ; Send_Z(-25) ; Move(); // Move to the 8th point

Send_X(-40); Send_Y(-40) ; Send_Z(5) ; Move(); // Move to the 9th point Send_X(-20); Send_Y(-50) ; Send_Z(20) ; Move(); // Move to the 10th point

Homming

CORONA XS modules do not have a switch input for home operation. The home operation is managed by your main processor and the switches depend on your main processor board. For this, feedrate is introduced in the form of SendVmax(HomeSpeed) as described earlier. It is advised that the HomeSpeed value is close to the Vmin value. In the 0x86?? Parameter, which is the GHM (Go Home) command, the “??” needs to be replaced with the axis that will perform the operation.

Bit 3 2 1 0 Value Means

0 0 0 0 1 Home operation on the X axis

0 0 1 0 2 Home operation on the Y axis

0 1 0 0 4 Home operation on the Z axis

1 0 0 0 8 Home operation on the E axis

For example, the parameter 0x8605 orders the X and Z axes to send to home position. Modules belonging to the axis to be reset when the reset command is sent, rotate the motors so that the mechanism moves in the direction of the home switch. Meanwhile, your main processor continuously reads the status of the switches placed at the zero position of the axes. If there is a switch pressed on any axis, it will send the STP (stop) command to the relevant module.

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The STP command is 0x87?? And has an 8-bit parameter. The bits of the parameter are created according to the table below.

Bit values Means

1 Stop the X axis

2 Stop the Y axis

4 Stop the Z axis

8 Stop the E axis

For example, the 0x8704 command orders the Z motor to stop. Following this command, the module will stop the motor. However, during this period, the mechanism will have pressed the switch and moved an amount. The real zero point allows the main processor to read the home switch position and if it is still off, very small steps are made on the axis with the go one-step command. The move one-step command SSP (single step) is 0x88?? And has an 8-bit parameter.

Bit 7 6 5 4 3 2 1 0 Value Meaning

0 0 0 1 0 0 0 0 0x10 Move one step forward on the X axis

0 0 0 1 0 0 0 1 0x11 Move one step backwards on the X axis

0 0 1 0 0 0 0 0 0x20 Move one step forward on the Y axis

0 0 1 0 0 0 1 0 0x22 Move one step backwards on the Y axis

0 1 0 0 0 0 0 0 0x40 Move one step forward on the Z axis

0 1 0 0 0 1 0 0 0x44 Move one step backwards on the Z axis

1 0 0 0 0 0 0 0 0x80 Move one step forward on the E axis

1 0 0 0 1 0 0 0 0x88 Move one step backwards on the E axis

For example, the 0x8854 command orders the X axis to move 1 step forward (0x10), while also telling the Z axis to move 1 step backwards (0x44). (0x10 + 0x44 = 0x54) Short reminders The position of the home switches whether on the left or right of the mechanism determines the direction of rotation of the motors. This was explained in Table 2. If the feedrate (Vmax) value is not defined for the new movement commands after this home operation is completed, the parameter used in the home operation continues to be used. Unlike other commands, the STP command can be sent even when the Ready signal

is 0.

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9- Stepper Motor Specifications

Specifications of the stepperper motor used in the 2S model.

Step Angle

Motor Length

Nominal Current

Phase Resistance

Phase Inductance

Holding Torque

Rotor Inertia

Number of Cables

Weight

(Deg) (mm) (A) (Ohm) (mH) (Ncm) gcm² (gr)

1.8 40 2 1.1 2.6 45 54 4 350

Specifications of the stepperper motor used in the 3S model.

Step Angle

Motor Length

Nominal Current

Phase Resistance

Phase Inductance

Holding Torque

Rotor Inertia

Number of Cables

Weight

(Deg) (mm) (A) (Ohm) (mH) (Ncm) gcm² (gr)

1.2 40 2 0.8 1.2 45 54 3 350

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10 – Dimention of the Card Mounted on the Stepper

motor

11 – Order Information

CORONA – XS X: Number of phases of the motor, either 2 or 3. S: SPI Interface CORONA - 2S: 2 phase stepper motor and SPI interface CORONA - 3S: 3 phase stepper motor and SPI interface.