Redshift Project Depot

FRC 2018 (Power Up) => Robot Software => Topic started by: Louis L on January 11, 2018, 12:05:35 PM

Title: Hardware interface map
Post by: Louis L on January 11, 2018, 12:05:35 PM
This thread will always reflect what the hardware looks like from a software point of view. The top-most posting will be updated as necessary.

See the corresponding document in the hardware section that contains the a summary of all hardware subsystems. Link http://www.team4048.org/smf/index.php?topic=279.0 (http://www.team4048.org/smf/index.php?topic=279.0)

Overall Table
This is the master table. It contains all the important stuff that needs to be wired between the RoboRio and the external hardware. However, it does not contain all wiring. For example connections between limit switches and controllers are not listed. See the respective section below for more details.

Index CAN (PDP#) DIO PWM (PDP#) AIN
0 PDP unused unused  (Talon SR @ #8) absolute encoder FR
1 Steering FR (SRX @ #11) unused  unused  (Talon SR @ #9) absolute encoder FL
2 Steering FL (SRX @ #4) unused  unused  (Spark @ #6) absolute encoder RL
3 Steering RL (SRX @ #5) unused unused absolute encoder RR
4 Steering RR (SRX @ #10) unused  unused  (Spark @ #2) Sonar Right (WPIlib)
5 Drivetrain CIM FR (SRX @ #15) Distance quad A unused Sonar Left (WPIlib)
6 Drivetrain CIM FL (SRX @ #0) Distance quad B unused unused (WPIlib)
7 Drivetrain CIM RL (SRX @ #1) unused  unused unused (WPIlib)
8 Drivetrain CIM RR (SRX @ #14) unused unused N/A
9 Pigeon IMU (chassis) unused unused N/A
10 Elbow (SRX @ #13) N/A N/A N/A
11 Arm (SRX @ #12) N/A N/A N/A
12 Pincher (SRX @ #7) N/A N/A N/A
MXP0 unused N/A N/A Sonar Right (LabVIEW)
MXP1 unused N/A N/A Sonar Left (LabVIEW)
MXP2 unused N/A N/A unused
MXP3 unused N/A N/A unused

Joystick and Control
USB0 is left joystick (X/Y control)
USB1 is right joystick (rotate)
USB2 is gamepad

IMPORTANT
Drivetrain and Chassis
Four AndyMark AM3009 Swerve drive modules. Each consists of a CIM drive motor and RS775/PG71 steering motor. The digital signal from the PG71 encoder is fed to the Talon SRX. Absolute analog encoders output is fed to the RoboRIO.

Motor Controller (CIM) - 4 x TalonSRX
Motor Controller (RS775/PG71) - 4 x TalonSRX + breakout board
CIM FR - CAN 5
CIM FL - CAN 6
CIM RL - CAN 7
CIM RR - CAN 8
Steering FR - CAN 1
Steering FL - CAN 2
Steering RL - CAN 3
Steering RR - CAN 4
Absolute encoder FR - AIN1
Absolute encoder FL - AIN2
Absolute encoder RL - AIN3
Absolute encoder RR - AIN4

Distance CIM encoder, quadrature output A - DIN5
Distance CIM encoder, quadrature output B - DIN6

Intake
Two RS775-5 motors with CIM-SPORT 4:1 gearbox, one on the left and one on the right will suck in the Cube. Each has its own motor controller but they run off one PWM cable since they run in tandem. A pair of limit switches mounted at the rear of the cube storage area will be series wired and report back to the RoboRio that a Cube is present. These can optionally be wired to the controller's limit switch to stop the intake motors.

Motor Controller - Left Talon SR @ PWM0, Right Talon SR @ PWM1
Intake limit switch - two wired in series @ DIO7

One Bosch seat motor is used to deploy (raise and lower) the intake assembly. Two limit switches will define the up and down limits of travel. The limit switch signals will also be sent to the RoboRio for software detection. The Bosch has an output encoder that we may use. For now, just rely on the limit switches since its only ever used fully up or fully down.


Motor Controller - Spark @ PWM2
Limit switches @ DIO1 and DIO2


Arm
One mini-CIM with a 64:1 CIM-SPORT gearbox is used to move the arm up and down. This is controller by a Talon SRX with a optional local PID. Two limit switches prevent the arm from moving outside its expected range of motion.

Motor Controller - Talon SRX @ CAN 11

One PG27 gearmotor drives a lead screws for 12 inches of travel to extend and retract the arm to keep it within the 16 inch boundary. There is one rotation per inch of travel. Two limit switches will limit the travel of the extension. A multi-turn potentiometer reads the rotation and returns a voltage value to the RoboRio to report distance (it does not go to an SRX because the extension to height curve is complex and better off controlled by the cpu).

Motor Controller - Spark @ PWM 3


Arm rotation potentiometer, continuous, 5K linear, 0.25W, plastic, 10% 
Extension potentiometer. 10 turn, 1K linear, 2W wirewound 5% - MXP AIN3 (also AIN7)

Claw
There are several sensors on this subsystems; some are local loops and some go to the RoboRio.

One snowblower motor open and closes the claw to release and grip the Cube respectively. There is no backdrive so once we grip the Cube, we can turn off the motor. Two limit switches define the absolute min and max positions of the opening.

Motor Controller - Talon SRX @ CAN 12


Another snowblower (?) motor pitches the gripper up and down. Two more limit switches limit the motion of this rotation. It would be advantageous to keep the Cube level during transit. An Analog Devices ADXL362 MEMS accelerometer can be mounted on the claw. A 10 wire cable carrying SPI signals to the RoboRio will allow the software to level the gripper. Note that this leveling should be done when the robot is still as motion will likely throw off the sensors.

Motor Controller - Talon SRX @ CAN 13


A switch mounted on the gripper will sense the top of the crate when it makes contact with the gripper. Since crates can be either 11 or 13 inches off the ground, we need to know when to stop lowering the arm. This sensor will be wired directly to the RoboRio

Limit Switch - DIO 0

An optional pressure sensor will tell software how much force is exerted on the Cube. Software can also monitor the current draw on the motor to determine when to stop driving the motor.

Pressure sensor - MXP AIN2


Climber
One Mini-CIM with a 64:1 Banebot P80 gearbox is used to pull the robot up. This is controlled by a Talon SRX and can be monitored over the CAN bus for current sensing (if needed). Alternatively we can use any other motor controller; or even a Spike relay.
Motor Controller - Talon SRX @ CAN 10

? One sonar mounted at an angle such that when the robot is hanging, it is pointing down. This is used to display a rough height on the console during the climb.
Sonar @ MXP AIN1

A limit switch is located on the climber such that when it is properly latched onto the Rung, the switch will inform the RoboRio that it is safe to start climbing.
Limit Switch @ DIO3

Pincher
This device replaces the old Claw/Gripper. It consists of 2 arms that open and close around a Cube to grab it. It is powered by a Snowblower motor attached to a Talon SRX (CAN 12 PDP 7)

Elbow
This joint replaces the Wrist. It is powered by a PG71 connected to a Talon SRX (CAN 10, PDP13). It has limit switches and hard stops that prevent it from moving outside its intended range of motion.

Camera
One Microsoft HD3000 camera mounted towards the front to give the drive team a forward view when grabbing or placing Cubes.
Actual location is TBD. Note that the camera has about a 68 degree horizontal and 30+ degree vertical field of view.
HD3000 @ USB port on RoboRio.
Title: Re: Hardware interface map
Post by: Louis L on January 14, 2018, 11:03:00 AM
Adding joystick and game controller definitions.
USB0 is left joystick (X/Y control)
USB1 is right joystick (rotate)
USB2 is gamepad
Title: Re: Hardware interface map
Post by: Louis L on January 17, 2018, 03:58:51 PM
Has anyone thoughts about sensors? Here are some I'd like to see.
I'm sure there's more. Let's hear it.
Title: Re: Hardware interface map
Post by: Louis L on January 17, 2018, 04:28:42 PM
Added more details to Climber and Intake in OP
Title: Re: Hardware interface map
Post by: Louis L on January 17, 2018, 04:57:18 PM
Added more details to Arm
Title: Re: Hardware interface map
Post by: ohad z on January 21, 2018, 11:13:27 PM
A couple of questions/comments:

Title: Re: Hardware interface map
Post by: Louis L on January 22, 2018, 02:01:14 PM
A couple of questions/comments:

  • There seem to be a few inconsistencies (unless I donít understand the notations) in the drive/steer motor definitions above: CAN IDs are 1-4 (steer) and 5-8 (drive), right? The table seem to indicate 0-3 and 4-7. Also, the wheel order is FR-FL-RL-RR (there is mention of FR-FL-RR-RL as well)
  • If we are short of SRX units, we may want to experiment with SR or PWM for the drive motors - they do not require any of the fancier modes and we are using them with no feedback as of now.  Even if we want to use feedback loop for them, since we only have one distance encoder, we may need to use the software PID since SRX PID would require 4 encoders. This may free up SRX for the intake and claw.
  • Arm is long and heavy. Will have to make sure whatever sensor used (Potentiometer) is sensitive and with enough resolution to be able to control the end of the arm with enough precision to avoid sway and missed goals. If in doubt, we may need to aim higher and let the cube drop.
  • How about IR sensor for the cube in the intake?
  • Some feedback (pot or encoder) for the extension mechanism
  • A concern was raised about engaging cubes that arrive at an angle and one idea was to engage different sides of the intake separately to get the cube aligned. Would require additional controller.
Title: Re: Hardware interface map
Post by: Louis L on January 22, 2018, 03:24:03 PM
I forgot to add that if we are short on SRX controllers, we can just replace any of the 4 controllers that drive the CIM motors on the swerve drives. We don't currently implement any local closed loop processing so any PWM-based controller can be used. The benefit of using an SRX in this case is the use of the CAN bus to simplify wiring - though even that is not as great as it sounds because of all the connections from controller to controller that must be made. The real benefit is in the reduction of PWM cables, thus allowing those PWM slots for other uses.
Title: Re: Hardware interface map
Post by: Louis L on January 25, 2018, 05:03:31 PM
Updated the gripper description for the accelerometer that will sense level-ness. The AD part does not plug into the SRX but rather into the RoboRio. We'll need a long 10-wire cable and let software take care of the leveling.
Title: Re: Hardware interface map
Post by: Louis L on January 27, 2018, 03:43:43 PM
Updated the Extension feedback device from a Quad Encoder to a multi-turn Potentiometer.
Title: Re: Hardware interface map
Post by: ohad z on January 27, 2018, 06:15:09 PM
Hardware map missing a few of the limit switches (e.g. arm up/down and extension in/out, gripper switch)
Title: Re: Hardware interface map
Post by: Louis L on January 27, 2018, 07:28:15 PM
See 3rd paragraph in OP. Most limit switches are not listed because they are wired to a local loopback at the controller. Only a few are wired to the RoboRio.
Title: Re: Hardware interface map
Post by: Louis L on January 27, 2018, 09:02:38 PM
Added Rung Detect switch to DIO3
Title: Re: Hardware interface map
Post by: ohad z on January 28, 2018, 12:10:09 AM
(Maybe Iím wrong) should you have Talon SRX for local feedback of limit switch? In this case youíd need the extension to be SRX rather than spark.
Title: Re: Hardware interface map
Post by: Louis L on January 28, 2018, 11:57:37 AM
No; the Spark, Talon SRX and Victor SP all support limit switches. Only the Talon SR does not.
The Talon SRX also supports other inputs like analog and digital I/O.
Title: Re: Hardware interface map
Post by: Louis L on February 03, 2018, 11:09:19 PM
We're going to use an ADXRS450 gyro instead of the accelerometer. This will be easier to use and we won't need to worry about the affects of movement on the readings. We also have 2 of them.
Title: Re: Hardware interface map
Post by: Louis L on February 09, 2018, 10:24:17 AM
Removed the pressure sensor from the Gripper. Steffen's testing showed it would be difficult to use due to the uneven surface on the milk crate Cube. The sensor requires that an additional contact surface be used but that would still have to be properly mated to the sensor to have it work just right.
Title: Re: Hardware interface map
Post by: Louis L on February 11, 2018, 10:56:58 AM
Removed the two potentiometers tied to the MXP board. These are routed to an SRX for PID use so we can read their values back over the CAN bus if we need to. Replace them with 2 additional sonars.
Title: Re: Hardware interface map
Post by: Vanshika C on February 17, 2018, 02:45:19 PM
PDP Port for Gripper -> 7
PDP Port for Wrist -> 3
Title: Re: Hardware interface map
Post by: Vanshika C on February 17, 2018, 07:08:06 PM
PDP Port for New Intake Motor - 2
Title: Re: Hardware interface map
Post by: Louis L on February 18, 2018, 04:46:51 PM
Table updated with latest updates from 2/17
Title: Re: Hardware interface map
Post by: Matt S on February 19, 2018, 12:54:10 PM
We are flipping X (Exchange) and A (Switch) on the controller because it makes more sense to have the lowest position as A, which is the lowest button on the controller.
Title: Re: Hardware interface map
Post by: Matt S on March 10, 2018, 04:45:55 PM
The pigeon gyro used for the wrist will be at CAN 14.
Title: Re: Hardware interface map
Post by: Louis L on March 12, 2018, 10:50:20 AM
Table in OP updated to reflect new pigeon on CAN 14