SparkFun ProDriver Hookup Guide

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Hardware Overview

Board Dimensions

Below, is a basic drawing of the board dimensions and component layout for the SparkFun ProDriver. For more detailed measurements, users should download and open the Eagle files from the GitHub repository or from the Documents tab on the product page.

  • The ProDriver includes four mounting holes that are compatible with 4-40 screws, standoffs, and other related hardware.
  • There are four 5mm latch pin terminals; a 2-pin terminal for power and three 4-pin terminals for the control pins and motor connections.
  • There is a 5.5 x 2.1 mm DC barrel jack as another power connection.
  • All the PTH breakout pins have a .10" spacing for headers or to solder more permanent connections.

board dimensions
SparkFun ProDriver board dimensions. (Click to enlarge)

For more details on the DC barrel jack, 2-pin latch terminal, and 4-pin latch terminal's dimensions, check out the documentation on their respective product pages.

Power

To power the ProDriver, users will need a power supply that has an output of 3.3 - 16V and can source at least 2A. We have provided three different methods for users to connect their power supply to the ProDriver:

  • A 5.5 x 2.1 mm DC barrel jack, which is simple and the easiest to use.
  • A latch pin terminal that is similar to a screw terminal, except toolless.
  • A set of PTH points (VM and GND) for users who wish to, more permanently, solder their power connections.

power block
The available power connections and status LED on the ProDriver. (Click to enlarge)

Users opting to use the DC barrel jack may find some of these accessories useful:

Barrel Jack Power Switch - M-F (3")

Barrel Jack Power Switch - M-F (3")

COM-11705
$2.50
Barrel Jack Extension Cable - M-F (3 ft)

Barrel Jack Extension Cable - M-F (3 ft)

COM-11706
$1.75
Barrel Jack Extension Cable - M-F (6 ft)

Barrel Jack Extension Cable - M-F (6 ft)

COM-11707
$1.95

⚡ Note: Do not connect or disconnect the motor while the ProDriver is powered; as it may damage the ProDriver.

Power Status LED

A power LED status indicator is also provided on the ProDriver. The LED turns on once the motor power supply is connected and the attached voltage regulator outputs 3.3V. The LED can be disabled by cutting the LED jumper.

power LED
LED jumper

The power LED and LED jumper on the ProDriver. (Click to enlarge)

3.3V PTH Pin

A 3.3V PTH connection is broken out amongst the other pin connections. It is connected to the 3.3V output of the LM117 voltage regulator, which is powered by the motor power supply input.

3V3 pin
The 3V3 PTH pin on the ProDriver. (Click to enlarge)

Power Protection

The ProDriver includes a safety features to protect the board and power supply. There is a protection diode to prevent reverse current and a thermal fuse to prevent current from being overdrawn.

⚡ Note: We have provided bypass jumpers for more advance users to circumvent these safety features; however, we recommend NOT modifying them, unless you absolutely know what you are doing. Users can easily damage or destroy their ProDriver and/or power supply by modifying the jumpers.

power protection jumpers
The D1 BP and PTC BP jumpers on the ProDriver. (Click to enlarge)

Pin Connections

The ProDriver was designed with latch pins to provide a completely solderless connection to get users up and running faster. We have also broken out those same connections with PTH points, for a more permanent installation. (*These latch pins are great! Just as secure as a screw pin terminal, but without the hassel.)

power LED
LED jumper

The control and motor connections on the ProDriver. (Click to enlarge)

More details on these pins are laid out in the following sections below, excluding the power pins. Details for the 3V3 and VM pins are described in the power section above.

Latch Terminals

When working with the latch terminals, there are two things to keep in mind. These should be fairly obvious, once you take a closer look at the jaws or clamping mechanism:

  1. If you look closely at the closed jaws or clamping mechanism, you will notice a small gap. Just like screw terminals, there is a minimum and maximum wire thickness for the jaws to physically clamp onto wires.
    • On some stepper motors, you may need to tin (i.e. add a little solder) the wire leads and thicken the wires just enough to be clamped.
  2. Make sure you are inserting the wire between the jaws. This should be fairly obvious; however, we have found overconfidence to be an Achilles' heel, in this case.
    • Looking to the right end of the picture, below, you will notice that with the latch partially closed, it is relatively easy to accidentally insert a wire above the jaws. This usually results in connections occasionally failing or secure wires slipping loose, moments after the board was working. This can be a head scratcher when the wires look like they are attached, but aren't properly connected. (*Occasionally, it wasn't apparent to us, until we looked closely at the latches.)

latching mechanism
The latching mechanism. (Click to enlarge)

Input Control Pins

The input control pins are used to interface directly with the TC78H670FTG motor driver. The ProDriver was designed with latch pins to provide a completely solderless connection to get users up and running faster. We have also broken out those same connections with PTH, for a more permanent installation. (*These latch pins are great! Just as secure as a screw pin terminal, but without the hassel.)

control pins
The input control connections on the ProDriver. (Click to enlarge)

For more details on the functions of the pins listed below, check out the datasheet for the TC78H670FTG.

Pin Name Label Description Operating Something
Ground Reference GND Ground (i.e. the 0V reference) 0V
Standby STBY This pin is used to either place the motor driver in standby or initiate one of the control methods.
  • Low: Motor driver is in standby; and the motor is released from any of the control methods.
  • High: On the up edge, the motor driver is configured for clock-in stepping or serial communication control based on the input state of the MODE0, MODE1, MODE2, and MODE3 pins.
0 to 3.3V (Default: Low or 0V)
Enable EN When the motor driver is configured for clock-in stepping, this pin is used to enable the motor output ON or OFF.
  • Low: Motor is off; all of the H-Bridge MOSFETs turn off and become high impedance (Hi-Z).
  • High: Motor is on; after the VM reaches the target voltage and becomes stable.
0 to 3.3V (Default: Low or 0V)
Error Detection Flag Output ERR If a thermal shutdown (TSD), over current (ISD), or motor load open (OPD) error, is triggerd, the pin output is pulled low. Under a normal operating status, the level of ERR pin is equal to the EN control voltage from outside. The error flag can be released by reconnecting the VM power or by setting the device to standby.
  • Low: An error has been detected/triggered.
  • High: Operation status is normal.
0 to 3.3V
MODE0
UP-DW (Clock-in)
S_DATA (Serial)
MODE0 MODE0: Utilized to configure the conrol method of the motor driver, when the standby pin is released. Based upon that control method, the pin will then function as one of the following inputs:
  • Serial Communication: Serial Data Input (S_DATA)
    • In serial mode, this line contains the serial data commands in a 32-bit format. After the serial setting is configured, the output is updated with the timing of the LATCH signal.
  • Clock-in Stepping (*Variable Mode Only): Step Mode Setting Input (UP-DW)
    • Low: Change step mode to high resolution
    • High: Change step mode to Low resolution
0 to 3.3V (Default: High or 3.3V)
MODE1
SET_EN (Clock-in)
LATCH (Serial)
MODE1 MODE1: Utilized to configure the conrol method of the motor driver, when the standby pin is released. Based upon that control method, the pin will then function as one of the following inputs:
  • Serial Communication: Latch Enable Pin (LATCH)
    • In serial mode, this line indicates the end of a data command.
  • Clock-in Stepping: Step Mode- Setting Enable Pin (SET_EN)
    • Low: Voids changes to the step size resolution setting.
    • High: Allow changes to the step size resolution setting. (Only available for Variable Mode)
0 to 3.3V (Default: High or 3.3V)
MODE2
CLK (Clock-in)
S_CLK (Serial)
MODE2 MODE2: Utilized to configure the conrol method of the motor driver, when the standby pin is released. Based upon that control method, the pin will then function as one of the following inputs:
  • Serial Communication: Serial Clock Input Pin (S_CLK)
    • In serial mode, this line contains the clock signal for serial data commands.
  • Clock-in Stepping: Step Clock Input Pin (CLK)
    • Up-Edge: Shifts the electrical angle by a single step (size).
    • Down-Edge: N/A
0 to 3.3V (Default: High or 3.3V)
MODE3
CW-CCW (Clock-in)
MODE3 MODE3: Utilized to configure the conrol method of the motor driver, when the standby pin is released. The pin will then, only function as an input for clock-in stepping:
  • Clock-in Stepping: Current Direction Setup Pin (CW-CCW)
    • Low: Counter-clockwise operation (CCW)
    • High: Clockwise operation (CCW)
0 to 3.3V (Default: High or 3.3V)
3.3V Reference 3V3 Connected to the 3.3V output of the LM117 voltage regulator, which is powered by the motor power supply input. 3.3V
Current Threshold Reference VREF Connected to the 10 kΩ potentiometer that controls the maximum drive current to the stepper motor coils. Iout (max) = 1.1 × Vref (V) 0 to 1.8 V
⚡ Note: From the datasheet, the TC78H670FTG is compatible with 3.3 and 5V logic levels on the control pins. The electrical specifications for the input voltage listed at a 5.5V maximum, with a 1.5 and 0.7V threshold on the high and low signals respectively. For more details, check out page 31 of the datasheet and the schematic for the ProDriver.

Output Channel Pins

The output channel pins are used to drive the coils of the stepper motor. The paired outputs are connected to the two H-Bridges of the motor driver.

outout channels
The output motor driver channels on the ProDriver. (Click to enlarge)

Pin Name Label Description
Positive "A" Channel Output A+ The "A" channel motor output (+) pin
Negative "A" Channel Output A- The "A" channel motor output (-) pin
Positive "B" Channel Output B+ The "B" channel motor output (+) pin
Negative "B" Channel Output B- The "B" channel motor output (-) pin
Useful Resources on Stepper Motors:

For basic information on stepper motors, users should check out our Motors and Selecting the Right One tutorial. Additionally, we have included a few YouTube videos, below, that help explain the theory of the stepping functionality behind stepper motors. Users who have stepper motors with more than four wires, may also find this article enlightening.

Motors and Selecting the Right One

December 12, 2013

Learn all about different kinds of motors and how they operate.

An introductory video on stepper motor basics. Video courtesy of LearnEngineering.

An introductory video on stepper motor functionality. Video courtesy of GreatScott!.

A more in-depth video on stepper motor functionality. Video courtesy of Nanotec.

TC78H670FTG Motor Driver

The ProDriver is driven by the Toshiba TC78H670FTG stepper motor driver IC. The TC78H670FTG is a 2-phase stepping motor driver, intended for bipolar stepper motors. The chip features two H-Bridge motor drivers that provide users with step size resolutions ranging from full steps, half steps, and micro-stepping down to a 1/128 of a step. The TC78H670FTG can be controlled with the standard clock-in stepping, but it also has an additional option for serial communication.

TC78H670FTG IC
The Toshiba TC78H670FTG stepper motor driver IC on the ProDriver. (Click to enlarge)

Some of the advantages to the TC78H670FTG over a simple H-Bridge, include a standby function, selectable mixed decay, error detect flag output, clock- in stepping or serial communication control, software control of the current output, and a minimal parts bill of matierals (BOM). The serial command method is especially unique because it allows users to precisely control the phase, torque, current limit and mixed decay ratio of each coil during the motor operation. Additionally, while in most stepper motor driver ICs, an external trimpot is required to set the current limit; however, with the ProDriver, a simple serial command can be utilized to precisely adjust the current limit.

Characteristic Description
Motor Power Supply Voltage: 2.5 to 16.0V
Output Current: 2.0A (max)
Control Methods:
  • Clock-in Stepping
  • Serial Communication
Clock Frequency:
  • Clock-in Stepping: up to 400kHz
  • Serial Communication: 1 to 15MHz
Step Size Resolution:
Discrete Steps
  • Full step
  • Half step
Micro-Steps
  • 1/4 step
  • 1/8 step
  • 1/16 step
  • 1/32 step
  • 1/64 step
  • 1/128 step
Error Detection Functions:
  • Thermal Shutdown (TSD)
  • Over-current Shutdown (ISD)
  • Motor Load Open (OPD)
  • Under Voltage Lockout (UVLO)

Enable/Error Pin Functionality

On the ProDriver the EN and ERR pins are broken out separately; however, these connections are tied to the same pin on the TC78H670FTG, which operates as a control input and output for error flags. A typical application of the EN/ERR pin with a microcontroller is displayed below.

application for en/err pin
The EN/ERR pin application from the datasheet. (Click to enlarge)

This duality allows the TC78H670FTG to give users control of the power to the motor drive channels; while also providing autonomous functionality to disable its own power, when an error flag is triggered and simultaneously, provide an output indicator on the same pin.

en/err pin connections
The motor enable control switch and the connected EN and ERR pins. (Click to enlarge)

H-Bridge Power Control

The EN pin controls the ON/OFF operation of the H-Bridges to the motor outputs. When the EN pin is low, all of the H-Bridge MOSFETs turn off and become high impedance (Hi-Z). Likewise, when the EN pin is set high, the motor channel outputs will be driven normally, based on the stepping controls.

enable motor output settings
The EN pin functionality from the datasheet. (Click to enlarge)

Note: Users should avoiding motor operation during any VM power-on and power-off cycles by setting the EN pin low to disable the motor channel outputs. The EN pin can be set high after the power supply reaches the target voltage and becomes stable.
Motor Enable Switch

We have broken out EN pin control to a DPST switch. The switch allows users to easily disable power to the motor channels without connecting additional hardware.

motor switch
The motor enable control switch connected to the EN pin. (Click to enlarge)

Error Detection

The TC78H670FTG has a built-in functionality to detect thermal shutdown (TSD), over current (ISD), or motor load open (OPD) connection issues. When these errors are triggered, the ERR pin is pulled low. In a normal operating status, the level of ERR pin is equal to the EN control voltage from outside. After the error is triggered, the error flag can be released by reconnecting the VM power or by setting the device to standby.

Standby Function

The standby pin for the TC78H670FTG, is used to set up the control method for the motor driver. When the standby pin is low, the motor is released from any control methods and is in standby. On the up edge, of when the standby pin is set high, the motor driver is configured for clock-in stepping or serial communication control based on the input state of the MODE0, MODE1, MODE2, and MODE3 pins.

control method configuration
The configuration settings for the control methods, when the standby pin is set HIGH. Pulled from the datasheet. (Click to enlarge)

Control Methods

There are two different communication or control methods for users to interface with the ProDriver. The control method is configured by the input state of the MODE0 - MODE3 pins, when the TC78H670FTG is released from standby mode. The TC78H670FTG features the common clock-in stepping method and a more unique serial communication control.

Serial Communication Control

This method is unique to the TC78H670FTG Toshiba motor driver. The control logic allows users to manipulate registers through serial communication, which provide control over:

  • The motor rotation direction (or polarity)
  • Maximum current output, torque
  • OPD error detection
  • Selectable mixed decay (used to finely tune drive current to the motor)
  • Driving the motor rotation (full steps only).

(*For more details on the configuration options for the available registers, refer to Section 9 of the datasheet.)

Clock-In Stepping Control

This is a standard method for controlling most stepper motor drivers. By default, the ProDriver is configured for clock-in stepping in the fixed mode with a step resolution of 1/128 of a step.

  • Step Resolution Modes
    With the clock-in control method, users can set up how the step resolution is configured. TC78H670FTG has the two modes for the step resolution settings, a variable mode and a fixed mode. These modes are also initiated by the input states of the MODE0 - MODE3 pins after releasing the standby pin, when the clock-in control method is configured. Below, is a table from the datasheet of the step resolution settings.
    • Variable Mode: The motor can be started with full step resolution and the step resolution can be changed while the motor is operating.
    • Fixed Mode: Once initiated, the step resolution is configured and maintained during the motor operation.

step resolution settings
The step resolution configuration settings for the clock-in method, from the datasheet. (Click to enlarge)

Once clock-in stepping and the step resolution are configured together. The TC78H670FTG awaits for the up-edge of the clock (CLK) signal, for the MODE2 pin, to before it shifts the motor’s electrical angle per step. The MODE3 pin, controls the clockwise/counter-clockwise (CW-CCW) rotation direction of the motor for clock-in stepping.

  • When the MODE3 pin is low, the motor is driven with a counter-clockwise (CCW) operation.
  • Like wise, when the MODE3 pin is high, the motor is driven with a clockwise (CW) operation.

clock-in stepping
The MODE3 (CLK) and MODE2 (CW-CCW) pin functionality for clock-in stepping, from the datasheet. (Click to enlarge)

Step Resolution Transition

In variable mode, users can transition between different ranges of step size resolutions with the MODE0 and MODE1 pins. To enable the transition between step size resolutions, the MODE1 (SET_EN) pin must be high, when the TC78H670FTG is in variable mode for clock-in stepping. The MODE0 (UP-DW) pin is used to control the direction of the step size transition.

  • When the MODE0 pin is low, the step size resolution is increased to a smaller step size (i.e. from 1/4 to 1/8 of a step).
  • Like wise, when the MODE0 pin is high, the step size resolution is decreased to a larger step size (i.e. from 1/8 to 1/4 of a step).

step size resolution control
The MODE1 (SET_EN) and MODE0 (UP-DW) pin functionality for transitioning the step size resolution during clock-in stepping, from the datasheet. (Click to enlarge)

The transition between step size resolutions occurs, synchronously with the up-edge of the next clock signal. It should also be noted, that the transition can only change the step size resolution one increment at a time (i.e. it takes three clock cycles to transition from a 1/4 step size, down three sizes, to a 1/32 step size resolution).

Maximum Drive Current

The maximum drive current for the ProDriver is limited to 2A (max). However, the peak output current can be controlled with two different methods.

Hardware: The first method controls the drive current through the reference voltage (Vref). The reference voltage, can be configured utilizing the external potentiometer or VREF breakout pin.

pot and vref pin
The potentiometer and VREF pin that can be utilized to control the maximum drive current.

For the hardware control, the maximum drive current can be calculated with the following equation:

hardware equation

Software: The second method controls the drive current through software. Utilizing serial communication to the TC78H670FTG, the registers can be configured to limit the maximum drive current. The maximum drive current can be calculated with the following equation, based on the configured registers:

software equation

Chopping Current Drive

Chopping is a technique that is used to control the average current per phase, by rapidly switching a relatively high output voltage to the motor coils, on and off. This technique improves the current rise time in the motor and improves the torque at high speeds, while maintaining a high efficiency in the constant current drive.

chopping frequency resistor table
A table with the resistor values used to modify the OSCM oscillation and chopping frequency, from the datasheet. (Click to enlarge)

On the TC78H670FTG, the OSCM oscillation frequency (fOSCM) and chopping frequency (fchop) are adjusted with an external resistor (ROSC), connected to the OSCM pin. By default, a 47 kΩ resistor is utilized. However, users can modify the ROSC resistor value by cuttin the OSCM BP jumper and soldering a resistor to the provided OSCM PTH connections.

OSCM adjustment
The OSCM BP jumoer and OSCM PTH points on the ProDriver. (Click to enlarge)

Heat Sink

There is a thermal ground plane on the bottom of the board available for users to attach a heat sink(s) with some thermal tape, if necessary. However, after several tests by the engineer for this product, we have determined that for most use cases, a heat sink probably won't be necessary.

thermal plane
The thermal ground planes on the bottom of the ProDriver. (Click to enlarge)