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Pololu A4988 - stepper motor driver RepRap 35V / 2A*

Stepper motor driver based on the A4988 system. Voltage supply in the range of 8 to 35 V with maximum current consumption of 2 A per coil. Maximum resolution: 1/16 of a step. The module allows for current flow up to 1 A without a radiator.

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PLL-00148

Dodano produkt do koszyka

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Price 19,97 zł

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-15%

23,50 zł

Specification:

  • The motor supply voltage: 8 V to 35 V
  • Current: 1A max. per coil ( if applying cooling to 2 A)
  • Supply voltage of the logic part: 3 V - 5.5 V
  • The simple control interface
  • Work in 5 different modes: full step, 1/2, 1/4, 1/8 and 1/16 step
  • The ability to adjust the current consumed by the motor with a potentiometer
  • Overheat protection system
  • The module is fully compatible with the predecessor: A4983

 

Set includes:

 

Description

The system allows you to control a stepper motor using a device that allows you to generate the logical states, for example, Arduino, STM32Discovoery, the Raspberry Pi or of any microcontroller. The Pololu module is characterized by a very simple operation. In order to rotate the motor one step further, you must specify the STEP with high state (logical one), another sequence of zeros and ones, moves the motor one step further, etc. The choice of direction is accomplished by specifying the state on the DIR lead(e.g. low state - clockwise, high stae - counterclockwise). The driver also has the choice of resolution of operation of the engine.

 

Connecting the driver

To control a bipolar stepper motor, it is necessary to connect the system in accordance with the figure below. In the case of the control of unipolar engine, you must read the instructions. If the nominal voltage of the motor is lower than required power source of the driver (8V), you should manually, with the potentiometer, set the current limit.

 

Sposób podłączenia sterownika silnika krokowego.

The illustration shows the minimum connection of the driver. Pin RESET,by default, is not connected, to start the system, it is necessary to indicate the high state on it. This can be done by combining it with an adjacent pin SLEEP.

Power

To power the logic part of the module, you need the voltage which ranges from 3 V to 5.5 V, which should be brought to the pin VDD. The motor supply voltage is in the range from 8 V to 35 V is indicated on the pin VMOT. The system can control the engines with a nominal voltage lower than the required 8 V. In this case, it is necessary to limit the maximum current consumption through the potentiometer, so as not to exceed the maximum voltage of the motor. For example, for a motor with a resistance of 5 Ω on one coil and a current consumption of 1 A, the nominal supply voltage of 5 V. Power with the voltage of 12 V to limit the current, so it does not exceed 1 A.

 

Attention!

The connecting and disconnecting the engine while the driver is turned on, can damage the system.

 

 

Resolution

The step size is selected via the inputs MS1, MS2, MS3. Possible settings are shown in the table below. Inputs MS1, MS2 and MS3 have internal resistor pull-down (100kOm).

 

MS1MS2MS3Resolution
lowlowlowFull step
highlowlow1/2 step
lowhighlow1/4 step
highhighlow1/8 step
highhighhigh1/16 step

 

 

Other inputs

One pulse specified on the pin STEP causes one step of the motor in the direction selected by indicating the appropriate logic state on the pin DIR. Leads STEP and DIR are not internally pulled up. If the motor should only rotate in one direction, the DIR pin can be permanently connected to VCC or GND.

 

The system has three other inputs for monitoring power consumption: RESET SLP and EN and their description is in documentation. Please note that the pin RESET is not pulled to anything. If not used, you can connect it to the adjacent pin SLEEP.

 

Current limit

The system can be controlled by the engines with a nominal voltage lower than the required 8 V. In this case, it is necessary to limit the maximum current consumption through the potentiometer, so as not to exceed the maximum voltage of the motor. For example, for a motor with a resistance of 5 Ω on one coil and a current consumption of 1 A, the nominal supply voltage of 5 V. Power with voltage of 12 V to limit the current, so it does not exceed 1 A.

The A4988 module allows for active current limitation with the potentiometer. One of the ways of the introduction of restriction is to set the driver to full step and measuring the current passing through one coil without indicating the signal at the input STEP. The measured current is 70% of the established limit (both coils are always on and limited to 70% in full step mode). Another way is to measure the voltage at lead REF (marked with a circle on the PCB), as well as the calculation of the current limit (measuring resistors have a value of 0.05 Ω). More detail in the documentation for the A4988 chip.

 

Heat dissipation

The tile was designed so that it can dissipate heat when the current consumption is about 1A per coil. If the current is much higher, use an external heatsink, to the assembly of which, can be used thermally conductive glue.

 

 

Scheme

The system includes the necessary passive components for the correct operation of the driver. The scheme of connection is shown in the figurs below.

 

Schemat sterownika silnika krokowego

 

 

In our offer is also chip A4988.

 

SAME DAY SHIPPING

Posting the payment for the order on our account on a business day up to 13:00 means sending the goods on the same day!

 

The time of payment depends on the hours of ELIXIR session of the sender's bank and the recipient of the transfer (more information on this subject, for example on the websitehttp://www.kiedy-przelew.pl/).

 

The table presents available forms of delivery in Poland

 

Carrier and
regulations

Bank wire
transfer

Payment
by cash

Delivery
time

Poczta Polska

terms of service

9,90 PLN17,90 PLN1-3 days

Kurier GLS

terms of service

14,90 PLN22,90 PLN

1-2 days

Paczkomaty 24/7 

terms of service

12,90 PLN-1-3 days

If the amount to pay for products exceeds 500 PLN
Delivery is for free!

 

  • Free delivery of orders over 500 PLN does not apply to parcels addressed outside of Poland.
  • Free delivery does not apply when changing orders.
  • The delivery period is counted in working days from the date of dispatch of the order.