Texas Instruments Stellaris MDL-BDC24 User manual

MDL-BDC24-GSG-04 Copyright © 2009–2011 Texas Instruments
Getting Started Guide
Stellaris® MDL-BDC24 Brushed DC Motor
Control Module

2January 5, 2011
Copyright
Copyright © 2009–2011 Texas Instruments, Inc. All rights reserved. Stellaris and StellarisWare are registered trademarks of Texas Instruments.
ARM and Thumb are registered trademarks, and Cortex is a trademark of ARM Limited. Other names and brands may be claimed as the property
of others.
Texas Instruments
108 Wild Basin, Suite 350
Austin, TX 78746
http://www.ti.com/stellaris

Stellaris® Brushed DC Motor Control User’s Manual
January 5, 2011 3
Table of Contents
Chapter 1: Introduction to Jaguar...................................................................................................................5
Features.............................................................................................................................................................. 7
Differences between the MDL-BDC and MDL-BDC24 ....................................................................................... 8
Warnings............................................................................................................................................................. 8
Chapter 2: General Operation..........................................................................................................................9
Operating Modes .............................................................................................................................................. 10
Fault Conditions ............................................................................................................................................ 10
Coast/Brake Jumper ..................................................................................................................................... 11
Power and Motor Wiring ............................................................................................................................... 11
Chapter 3: Servo/PWM-based Control..........................................................................................................13
Servo-style PWM Speed Control Input ............................................................................................................. 13
Calibrating the PWM Input ............................................................................................................................ 13
Chapter 4: Introduction to Network-Based Control.....................................................................................15
Network Security and System Safety ............................................................................................................... 15
Trusted Mode (FIRST Robotics Competition feature) ...................................................................................... 15
Chapter 5: Operation using the RS232 Interface.........................................................................................17
BDC-COMM Application Overview ................................................................................................................... 17
Chapter 6: Firmware Update Using BDC-COMM .........................................................................................19
Important Information........................................................................................................................................ 19
Step 1: Hardware Setup................................................................................................................................ 19
Step 2: Run BDC-COMM.............................................................................................................................. 20
Step 3: Assign Unique CAN ID ..................................................................................................................... 20
Step 4: Update Firmware .............................................................................................................................. 20
Chapter 7: Closed-Loop Control Options.....................................................................................................21
Wiring................................................................................................................................................................ 21
Constant Current Control.................................................................................................................................. 22
Position Control using an Encoder ................................................................................................................... 22
Position Control Using a Potentiometer............................................................................................................ 23
Speed Control................................................................................................................................................... 23
Chapter 8: Operation Using the CAN Interface............................................................................................25
CAN Overview .................................................................................................................................................. 25
CAN IDs............................................................................................................................................................ 25
CAN Network .................................................................................................................................................... 25
Control Options for Networked Jaguar Modules ............................................................................................... 26
Appendix A: Jaguar Communication Cables...............................................................................................29
CAN Terminator................................................................................................................................................ 29
CAN Cable........................................................................................................................................................ 29
CAN Cable Assembly ................................................................................................................................... 30
CAN Cable Pin Assignments ........................................................................................................................ 30
RS232 Cable .................................................................................................................................................... 30
RS232 Cable Assembly ................................................................................................................................ 30
RS232 Cable Pin Assignments..................................................................................................................... 31
External References ......................................................................................................................................... 31

4January 5, 2011

January 5, 2011 5
Introduction to Jaguar
Texas Instruments presents the next generation FIRST Robotics Competition (FRC) motor
controller: the MDL-BDC24 brushed DC motor control (also known as Black Jaguar). The
MDL-BDC24 builds on the success of the first-generation MDL-BDC (Gray Jaguar) by adding an
RS232-to-CAN gateway and enhanced electrical performance. Designed specifically for the FRC
competition, the MDL-BDC and MDL-BDC24 modules facilitate the design of complex robots
within the short six-week FRC build period.
This document provides a complete description of how to use Jaguar in both Networked and Servo
control modes. Information applies to both the MDL-BDC and MDL-BDC24 models except where
noted. Additional information can be found in the MDL-BDC and MDL-BDC24 data sheets, as well
as in related application notes.
Figure 1-1. Next Generation Brushed DC Motor Control Module, MDL-BDC24
The flowchart in Figure 1-2 provides an overview of the process of developing with the MDL-BDC
and MDL-BDC24 modules. We suggest checking off each step as it is completed.
CHAPTER 1

Introduction to Jaguar
6January 5, 2011
Figure 1-2. MDL-BDC24 Development Process
Getting Started
with Jaguar
Connect:
- Servo cable
- Power cable
- Motor cable
Decision:
Control using
Servo/PWM or
Network?
Read Jaguar GSG
Introduction and
General Operation
Chapters
Servo/PWM
Read Jaguar GSG
Servo/PWM
Control
Chapter
Ready to Run!
Read Jaguar GSG
Introduction to
Network Control
Chapter
Decision:
CAN Interface
Method
Network
Read 3
rd
Party
CAN Bridge
documentation
3
rd
Party CAN Interface
Assemble and
connect cables:
- RS232/CAN
- Power
Read Jaguar GSG
Operation using
RS232 Chapter
Read Jaguar GSG
Firmware Update
using BDC-COMM
Chapter
Update firmware in
each Jaguar
Connect to cRIO-
based FRC control
system
Black Jaguar Bridge
Read Jaguar GSG
Operation using
the CAN Interface
Chapter
Appendix A
Jaguar Cable
Assemblies
Assign CAN ID
(ID Value > 1)

Getting Started Guide
January 5, 2011 7
Features
The Stellaris® Brushed DC Motor Control Module with CAN (MDL-BDC24) offers a variable speed
control for 12 V and 24 V brushed DC motors at up to 40 A continuous current. The motor control
module includes high performance Controller Area Network (CAN) connectivity and a rich set of
control options and sensor interfaces, including analog and quadrature encoder interfaces. The
high-frequency PWM on the MDL-BDC24 enables DC motors to run smoothly and quietly over a
wide speed range. The module uses highly optimized software and a powerful 32-bit Stellaris®
microcontroller to implement open-loop speed control as well as closed-loop control of speed,
position, or motor current.
The MDL-BDC24 provides the following features:
Quiet control of brushed DC motors
–15 kHz PWM frequency
Three options for Speed control
–Industry-standard R-C servo type (PWM) interface
–Controller Area Network (CAN) interface
–RS232 serial interface
CAN communication
–Multicast shared serial bus for connecting systems in electromagnetically noisy
environments
–1M bits/s bit rate
–CAN protocol version 2.0 B
–Full configurability of module options
–Real-time monitoring of current, voltage, speed, and other parameters
–Firmware update
RS232 serial communication
–Bridges RS232 port to a CAN network
–Directly interfaces to a PC serial port or National Instruments cRIO
Status LED indicates Run, Direction, and Fault conditions
Motor brake/coast selector
Limit switch inputs for forward and reverse directions
Quadrature encoder input (QEI)
–Index input
–5 V supply output to encoder
Analog input
–Accepts 10 kΩpotentiometer or 0-3 V input
Screw terminals for all power wiring
Headers (0.1 inch pitch) for all control signals

Introduction to Jaguar
8January 5, 2011
Differences between the MDL-BDC and MDL-BDC24
First generation Jaguar motor controls (MDL-BDC) have similar capabilities to the second
generation Jaguar (MDL-BDC24). Functional differences are summarized in Table 1-1.
Internally, the MDL-BDC24 is a completely new design that makes use of switching converters and
synchronous rectification to improve overall energy efficiency.
Software should be updated to the latest version to ensure that all capabilities of the MDL-BDC or
MDL-BDC24 module are enabled and functional.
Warnings
WARNING – Be aware of the following warnings. Failure to heed warnings can result in damage
to the module or invalidation of the module warranty.
Mount the Jaguar module so that the vents in the top and sides of the unit are not restricted in
any way. Maintain a clearance of at least ½ inch between modules.
Reverse wiring is unprotected; doing so voids the Jaguar module's warranty.
Do not exceed the absolute maximum supply voltage (30 VDC for MDL-BDC24, 13 V for
MDL-BDC). Doing so causes permanent damage to the module.
Protect Jaguar from all situations where debris could enter through ventilation slots or
connector openings.
Table 1-1. MDL-BDC and MDL-BDC24 Differences
Feature
MDL-BDC (Gray) MDL-BDC24 (Black)
Part Number MDL-BDC MDL-BDC24
Voltage Range 6–13 V 6–30 V
RS232C Port No Yes
Terminal Screws Captive – Do not removea
a. Captive terminal screws should not be removed because metal debris can be created.
Loose – Okay to removeb
b. Non-captive screws are safe to remove and are compatible with ring-terminal use.

January 5, 2011 9
General Operation
This chapter describes the general operation of the MDL-BDC24 motor control module. Figure 2-1
shows the key features of the MDL-BDC24 motor control. Table 2-1 provides a key to the status
LED.
Figure 2-1. MDL-BDC24 Key Features
Table 2-1.
Table 2-2. Status LED
LED State Module Status
Normal Operating Conditions
Solid Yellow Neutral (speed set to 0)
Fast Flashing Green Forward
Fast Flashing Red Reverse
Solid Green Full-speed forward
Solid Red Full-speed reverse
Fault Conditions
Slow Flashing Yellow Loss of servo or Network link
Fast Flashing Yellow Invalid CAN ID
Motor
Out
(–) Motor
(+) Motor
(–) In
(+) In
From Power
Distribution
Module
Motoroutputisnotprotected
againstshort-circuits.
User Switch
Use hooks to prevent
wires shaking loose
Maintain0.5" clearance
around all vents
Status LED
Mounting holes
3.50" centers
Motor coast/brake jumper
Ma in ta in 0.5" cle ar ance
around all vents
For power wiring use
12AWGWirewith #6ring
or spade terminals
CAN Port
RS232/CAN Port
Anal og i np ut(0-3 V)
Encoder Input
Limit switch inputs
CHAPTER 2

General Operation
10 January 5, 2011
Operating Modes
The MDL-BDC24 can be controlled using either the Servo-style PWM Input or the CAN interface.
Table 2-3 compares the capabilities of each control method.
Table 2-3.
Jaguar supports the simultaneous use of CAN for monitoring and the Servo-style input for speed.
Fault Conditions
A slow flashing Red LED indicates that the MDL-BDC24 detected one of the following fault
conditions:
Power supply under-voltage
Over temperature
Over current
Limit switch activated in the current direction of motion
When a fault condition occurs, the motor shuts down and the LED indicates a fault state during the
fault condition and for 3 seconds after the fault cause is cleared (except for the limit switch fault,
Slow Flashing Red Fault condition
Calibration Conditions
Fast Flashing Red and Green Calibration mode active
Fast Flashing Red and Yellow Calibration mode failure
Fast Flashing Green and Yellow Calibration mode success
Slow Flashing Red and Green Calibration mode reset to factory
default settings success
Table 2-4. Control Method Comparison
Control Method
Servo-Style PWM input CAN/RS232C Interface
Speed Control Yes Yes
Analog Position Control No Yes
Encoder Position Control No Yes
Configurable Parameters No Yes
Voltage, Current
Measurement No Yes
Limit Switches Yes Yes
Coast/Brake Feature Yes Yesa
a. By default, the jumper sets coast/brake. Network commands can over-ride the jumper
setting.
Firmware Update No Yes
Table 2-2. Status LED (Continued)
LED State Module Status

Getting Started Guide
January 5, 2011 11
which is cleared instantly). A slow flashing Yellow LED indicates that the MDL-BDC24 is not
receiving a valid control signal.
Coast/Brake Jumper
The coast/brake signal controls the dynamics of the drive signal to the motor. When set to brake,
the MDL-BDC24 is able to achieve greater deceleration and holding torque because it decays
regenerative current from the motor.
The coast/brake signal can be set with a jumper or controlled by a signal from a digital source. A
single wire connected to the center (S) pin, is recommended. Do not connect to the + pin (+3.3 V)
of this connector as any mis-wiring could damage the MDL-BDC24.
The coast/brake jumper setting can be overwritten when using the CAN/RS232 interface.
Power and Motor Wiring
The Overview diagram (Figure 1-2 on page 6) shows motor and power connections to the
MDL-BDC24. For power wiring, use 10-12 AWG wire terminated with #6 ring or spade terminals.
The control is not protected against reverse polarity or short-circuits.

General Operation
12 January 5, 2011

January 5, 2011 13
Servo/PWM-based Control
The MDL-BDC and MDL-BDC24 both support speed and direction control through a servo-style
PWM input. Figure 3-1 shows the servo-wiring details.
Figure 3-1. Wiring for Servo-style PWM Control
Servo-style PWM Speed Control Input
The servo PWM input controls motor speed and direction. The digital signal must meet the timing
and voltage requirements listed in the MDL-BDC24 specifications. The center pin (+) has no
internal connection. Because the signal is optically isolated, both the signal (S) and GND (-) pins
must be connected to the signal source.
The servo-style PWM input is optically isolated. All other control inputs are non-isolated and are
referenced to the power supply (-).
Calibrating the PWM Input
To accommodate variation in the timing of the supplied signal, Jaguar has a calibrate feature that
sets new values for full-forward, full-reverse and points in between. Calibration is normally only
required in applications where the PWM source has uncertainties due to analog radio links or other
variables. Direct digital sources are unlikely to require calibration.
Motor
Out
(–) Motor
(+) Motor
PWM speed
signal from
Digital Sidecar +5V GN D
Reverse direction
switch(es)
Normally-closed
Limit switches
(–) In
(+) In
From Power
Distribution
Module
User Switch
PWM
+5V is optional (no internal connection)
Status L ED
Forward direction
swi tch(es)
Install jumpers if
limitswitches are
notused.
CHAPTER 3

Servo/PWM-based Control
14 January 5, 2011
To calibrate the servo-style PWM input for a specific range, connect a PWM source, then:
1. Hold down the USER switch with a straightened paperclip for 5 seconds.
2. The LED flashes Red and Green to indicate Calibration mode.
3. Instruct the controller to send a full-forward signal for one or more seconds.
4. Instruct the controller to send a full-reverse signal for one or more seconds.
5. The LED flashes Green and Yellow quickly to indicate a successful calibration.
The MDL-BDC24 samples these signals and centers the speed range and neutral position
between these limits. A calibration failure signals if an out-of-range signal is detected. This
condition is indicated by flashing the LED Red and Yellow.

January 5, 2011 15
Introduction to Network-Based Control
Both MDL-BDC and MDL-BDC24 support CAN-based control, configuration and firmware
updates. MDL-BDC24 also supports the same command set over RS232.
Network Security and System Safety
The factory default network protocol allows for very flexible control networks with all commands
being accepted and executed without restriction. However, a vulnerability is that faulty software
has the potential to send errant messages. To address the possibility that motors could run when
they are not supposed to, a special set of trusted commands have been added. This capability is
supported in an FRC-specific firmware update. All MDL-BDC and MDL-BDC24 modules must
have updated firmware if they are to be used with CAN or RS232 communication in an FRC
competition.
Trusted Mode (FIRST Robotics Competition feature)
Each MDL-BDC and MDL-BDC24 module expects to see a trusted message from the Host every
100 ms. If a trusted message is not received, the MDL-BDC and MDL-BDC24 module shut down
the motor output until trusted communication is restored.
Trusted communication relies on a proprietary protocol that defines a dynamic message token,
known only to the host driver and a specific MDL-BDC or MDL-BDC24 module.
Non-FIRST users should use the factory-default firmware (available in source form) which does
not implement trusted communication.
CHAPTER 4

Introduction to Network-Based Control
16 January 5, 2011

January 5, 2011 17
Operation using the RS232 Interface
The MDL-BDC24 supports a full set of network control and configuration functions over a standard
RS232C serial interface. The command protocol is essentially the same as the protocol used on
the CAN interface allowing the MDL-BDC24 to automatically bridge all commands between the
RS232 and CAN interfaces.
RS232 signals are implemented on the left-side NET connector, which has a special IOIOI
annotation as shown in Figure 5-1.
Figure 5-1. MDL-BDC24 Bridges for RS232 to CAN
See Appendix A, “Jaguar Communication Cables,” on page 29 for details of the RS232 cable
assembly. The recommended DB9 adapter design contains an integrated CAN terminator.
BDC-COMM Application Overview
BDC-COMM is a Windows application for configuring and controlling a Jaguar network using a PC’s
RS232 serial port. It is also a convenient tool for performing firmware updates. BDC-COMM requires
the use of an MDL-BDC24 to bridge RS232 to CAN. Figure 5-2 on page 18 shows the main GUI
window of the BDC-COMM application.
Motor
Out
(–) Motor
(+) Motor
(–) In
(+) In
From Power
Distribution
Module
DB9 Adapter
Connect to
Host Controller
(PC, cRIO)
To other CAN
Devices
Black Jaguar bridges
RS232 to CAN
CHAPTER 5

Operation using the RS232 Interface
18 January 5, 2011
Figure 5-2. BDC-COMM GUI Main Window

January 5, 2011 19
Firmware Update Using BDC-COMM
Firmware update capability allows Texas Instruments to provide new software, in binary format,
that contains feature enhancements and bug fixes.
Special firmware releases have been created for FRC 2010. Both MDL-BDC and MDL-BDC24
have firmware updates available. This firmware update must be installed prior to using RS232 or
CAN-based control. Firmware update is optional for Servo/PWM control.
Firmware update requires RS232 and CAN cables, at least one MDL-BDC24, the binary file, a PC
with an RS232 port, and a 12 V power source.
The BDC-COMM Application User’s Guide contains additional detail on using the tool for firmware
update as well as other configuration and control functions.
Important Information
Observe the following precautions when updating firmware:
We strongly recommend connecting only one Jaguar to the network at a time. The exception is
when updating a single first generation (MDL-BDC) Jaguar. To update an MDL-BDC Jaguar,
add only theMDL-BDC24 that is being used as the RS232-to-CAN bridge.
Use the correct binary file. For first generation MDL-BDC modules, the file is named
QS-BDC.bin. For second generation MDL-BDC24 modules (black), the file is named
QS-BDC24.bin
Step 1: Hardware Setup
Connect an MDL-BDC24 (black) to a PC following the information in Chapter 5, “Operation
using the RS232 Interface” on page 17.
If a first-generation (MDL-BDC) Jaguar (gray) requires firmware update, then connect it to the
MDL-BDC24 (see Figure 6-1).
Apply power. The LED on the Jaguar(s) flash yellow indicating loss-of-link.
Figure 6-1. Valid Configurations for Firmware Update
Connect to PC
Serial Port
Connect to PC
Serial Port
JaguarBlack Jaguar Black Jaguar
Ter m i nator
Termi nator
Firmware Update
Update Firmware
on this Jaguar
RS232/CAN Bridge Firmware Update
CHAPTER 6

Firmware Update Using BDC-COMM
20 January 5, 2011
Step 2: Run BDC-COMM
Run BDC-COMM.EXE.
The LED on the Jaguar(s) should now be solid yellow indicating a valid network link. If the LED
is not solid yellow, check all network connections as well as the BDC-COMM Com Port setting.
A valid link must be established before proceeding to the next step.
Step 3: Assign Unique CAN ID
If two modules are connected, each must have a unique CAN ID. The factory default CAN ID
is 1.
Assign the Jaguar modules the ID > 1 so that new Jaguar modules from the factory do not
operate on your robot.
Using the BDC-COMM application, select the System tab and enter a new ID (a unique
number from 2..63).
Click “Assign.” The LED on the module(s) starts flashing green.
Press the USER button on the module that is to receive the new ID. This must be done within
5 seconds or the operation times out.
The module’s LED blinks the number of times that corresponds to the ID if assignment was
successful (for example, if you assign the unique ID number of 5, the LED blinks five times).
A fast-flashing yellow LED indicates an invalid CAN ID. This can occur if an attempt is made to
reassign an ID that is already in use.
Step 4: Update Firmware
A valid link must be established before proceeding. Ensure that the LED indicates solid yellow.
It might be necessary to reconnect to the CAN network to synchronize the trusted link.
Select the board ID that you want to update using the “Board ID” menu.
Select File > Update Firmware from the top menu bar.
Browse to locate the appropriate binary file:
–The MDL-BDC24 (black) uses the qs-bdc24.bin file.
–The MDL-BDC (gray) uses the qs-bdc.bin file.
Click OK and then click Update.
A progress bar displays the firmware update progress.
When the firmware update completes, reconnect bdc-comm to the network to re-establish a
link.
The System tab in BDC-COMM displays the firmware version.