Description of product: Pololu DRV8834 stepper motor driver Low-Voltage 10,8 V 2A
The module is based on the DRV8834 driver from Texas Instruments allows you to control a stepper motor with a maximum current consumption up to 2A per coil, a voltage supply range from 2.5 V to 10.8 V. it is recommended to see the documentation of the driver.
Below are some of the main features of the product:
- The module has a simple interface pitch control and direction.
- Has the capability of operating in six modes: full, half-, 1/4-, 1/8-, 1/16- and 1/32 - step.
- Provides control of maximum motor current with the potentiometer, allowing you to use a voltage higher than the voltage for the motors so you can get more speed run action.
- The engines can be powered with voltage from 2.5 V to 10.8 V.
- Current consumption up to 2 A per coil (continuous 1.5 A).
- Thanks to the built-in voltage regulator, you should not allow additional power logical parts.
- DRV8834 works with systems with a voltage of logic like 3.3 V and 5 V.
- Is protected against too high current, temperature and short circuit protection and interlock system for the start-up at too low voltage.
- To increase the surface oddającej heat tiles were manufactured in the technology of four-ply with thickened cap of copper.
- The open fields of the mass from the bottom can be soldered elements cooling.
- The module is compatible from the point of view of dimensions and insights with a system based on the controller A4988.
In our offer we also have the drivers for the stepper motors on the other options working.
To control a stepper motor bipolarnym it is necessary to connect the system in accordance with the following figure. The driver allows to work with some engines unipolarnymi - details are in the instructions.
One pulse on the specified pin STEP causing one step of the motor in the direction selected by making the appropriate logic state (high or low) to the output DIR. Contacts STEP and DIR internally, free download via 200kΩ resistor, to ground (GND). If the motor needs to rotate in only one direction pin DIR you can leave not connected.
The system has two input power control: SLEEP, and ENBL, their description is in documentation. Please note that both the default output in the low state. To start the system, you need to bring SLEEP to pull to the voltage zasialnia - file logical unit (voltage in the range of 2.5 - 5.5 V). SLEEP can also be connected to the controller to dynamically control the state of the system.
The DRV8834 driver also has an output means, as FAULT. The status of the low (logical zero) indicates the emergence of nieprawidłości in the system, for example, the tripping of safety. On the Board output is connected with the contact SLEEP, and thus giving a high position to SLEEP pulls the pin to VCC (pull-up) FAULT. Through the application of consistent protective resistor output "FAULT" can also be connected to the voltage VCC, which makes the module is pin-compatible with the version of the A4988.
Power driver DRV8834
The chip can be powered with any voltage from 2.5 V to 10.5 V, connected between the terminal UMOT (+) and GND (-). The voltage must be filtered through the external capacitor placed as close as possible to the tile driver. Its capacity depends on the maximum current consumed by the motor.
In certain conditions, even a relatively low supply voltage may lead to stiletto high amplitude, exceeding the allowed value of 45 V. This situation causes irreversible damage to the system. One way to avoid this problem is the placement of the capacitor (at least 47 uF) as close as possible to UMOT and GND pins of the controller.
The connection and disconnection of the engine while the driver is turned on can damage the system!
Driver mikrokrokowy like the DRV8834 allows engine operation with high resolution to 1/32 step. The step size is selected using inputs M0 and M1 are the available modes are presented in the table below. By default, the output M1 of the internally filtered supply (through a resistor 200kΩ). The M0 input is not connected (floating mode). Leaving both pins open means that the choice of mode ¼ step.
Pin CONFIG allows you to change the mode of operation of the driver. The mode is phase/enable allows you to control two brushed DC motors. To change mode, you must also make jumper as shown in the figure below.
To maintain high switching speed steps, you can use a higher motor supply voltage than nominal. You should only limit the maximum current flowing through the coil until the values of engine performance.
The module allows the active current limit with the potentiometer. One of the ways the introduction of restrictions to set the driver to full step and measuring the current passing through one coil without signal at the input STEP. The measured current is 70% of the established limit (both coils are always on and limited to 70% of full step).
Another way is to measure the voltage at pin REF (marked with a circle on the PCB), as well as the calculation of the current limit (measuring resistors have a value of 0.1 Ohm). The current limit can be calculated from the formula:
Current Limit = VREF × 2
For example, if the engine can load up to 1A, the tension, the links at pine VREF should be set to 0.5 V.
The tile was designed so that it could conduct heat at a constant current of about 1.5 A to the coil. The system is able to provide short-time current current to 2.2 A, however, temperature protection shuts down the system at a current of around 2A. If the current is significantly higher, you should use an external radiator, which can be installed using glue termoprzewodzącego.
Diagram of the module
The system includes the necessary passive components for the correct operation of the driver. The scheme of connection shown in the figures below.
The main differences from version A4888
The DRV8834 module was designed to be compatible with the version based on A4988. The plates have the same shape, size and location of the contacts. However, there are several different between them:
- Pin is used as supply voltage logic part of the A4988 was replaced by the contact FAULT, because DRV8834 does not require additional power. FAULT connected through a protective resistor, and hence may be used in system design for the A4988 module, this pin is the supply voltage, in the list of logical (2,2 V to 5,5 V).
- In module DRV8825 SLEEP pin default pulled up to a power source, connected with a FAULT output through a 10K resistor. In systems designed under the A4988 chip, using a voltage of a logic part connected to the FAULT, the 10K resistor pulls the SLEEP voltage setting is high.
- The potentiometer which limits the maximum current for motors is in a different place
- DRV8834 allows you to work in 1/32 steps, while in the A4988 worked down to 1/16-step
- The time required to complete one pulse, 1.9 us, while the A4988 will need 1 us
- DRV8834 allows you to work with lower supply voltages - range: 2.5 V - 10.8 V
- DRV8834 can provide a current of higher amperage from the A4988 without any additional cooling (1.5 A 2A temporary)
- O have different names but perform the same function
Minimum connection driver connection module A4988.
- Supply voltage: 2.5 V - 10.8 V
- Continuous current per coil: 1.5 A
- Maksmalny instantaneous current per coil: 2 And
- Voltage digital logic supply: 2.5 V to 5.5 V
- Modes of operation: 1, 1/2, 1/4, 1/8, 1/16, and 1/32-step
- Dimensions: 20 x 15 mm
- Weight: 1.6 g (without connectors)