Summary of Contents for CTR Electronics CANCoder
- Page 1 CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 CANCoder User’s Guide Revision 1.4 Cross The Road Electronics www.ctr-electronics.com Cross The Road Electronics Page 1 02/13/2023...
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Page 2: Table Of Contents
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 Table of Contents 1. Device description ..................................4 1.1. Kit Contents ................................... 4 1.2. Features ....................................4 1.3. Electrical Specifications ................................. 5 1.4. Magnet Specification ................................5 1.5 General Specification ................................5 1.6. LED States ..................................... 6 1.6.1. - Page 3 CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your CTRE products. To this end, we will continue to improve our publications, examples, and support to better suit your needs.
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Page 4: Device Description
02/13/2023 1. Device description The CTR CANCoder is a rotary sensor that can be used to measure rotational position and velocity. The device senses the magnetic field of a diametrically polarized magnet to determine rotational position with 12 bit precision. The device is capable of providing a relative position measurement and an absolute position measurement simultaneously over the CAN bus. -
Page 5: Electrical Specifications
Condition Unit Discrepancy between Absolute CANCoder is still when booting degrees Position and Regular Position. CANCoder is rotating < 60 RPM 1.44 degrees Note 1: CANCoder is configured to boot to absolute position Cross The Road Electronics Page 5 02/13/2023... -
Page 6: Led States
1.6. LED States The CANCoder features a tri color LED that indicates magnetic field strength and CAN bus health. This feature can be used to confirm proper magnet distancing and proper CAN bus wiring. The table below shows the possible color states and their respective magnetic field strength. -
Page 7: Dim Rapid-Blink Led
Boot to Zero (relative mode) – CANCoder will immediately begin blinking according to the LED table in section 1.6 Boot to Absolute – CANCoder will go solid red LED as it seeds its position register to the absolute position. If the magnet is too far away the LED will be solid red for up to 500ms. -
Page 8: Installation
Although similar to the CTRE “Magnetic Encoder”, the CANCoder requires CAN bus and power leads to be wired to the CANCoder circuit board. This is also covered in the sections below. -
Page 9: Magnet Placement
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 2.1. Magnet Placement The typical distance “Z” between the magnet and the housing detent, as illustrated in Figure 2.1, is .75mm (.030) to 1.5mm (.059”). The table below shows the relationship between LED color and magnet Z distance. -
Page 10: Wiring
02/13/2023 2.2. Wiring The CANCoder printed circuit board features six through-holes to make soldering easier. Note the CAN H and CAN L lines each have two through-holes. This allows two CAN bus pigtails, each with a CANH/CANL pair. Strip ~20 AWG wire and pass through the 100mil through-hole. -
Page 11: Encoder Mounting
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 2.3. Encoder Mounting The encoder should be mounted to a surface that is rigid and in a fixed position relative to the magnet and rotary shaft. A center hole is not required provided the material the encoder is mounted to has a relative magnetic permeability similar to air (~1.0). -
Page 12: Modifications To Cots Components
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3. Modifications to COTS Components There are several companies that make commercial off the shelf, or COTS, transmissions and gear boxes. Some of these components contain interfaces for optical or shaft type encoders. This section describes modifications of two COTS transmissions, the AndyMark Toughbox Mini (am-0654) and the VEX PRO Single Speed Double Reduction gearbox (217-2454). -
Page 13: Facing Off The Shaft End
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3.1.2. Facing Off the Shaft End Once the Extrusion has been removed, the end of the shaft will need to have a smooth even surface. This will make the following steps go smoother. Using a facing tool, turn the face of the shaft down until it is smooth and all of the remaining .250”... -
Page 14: Boring The Magnet Pocket
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3.1.3. Boring the Magnet Pocket After the shaft has been faced, a pocket will need to be bored to house the magnet. The depth of this pocket is determined by the distance the encoder is located from the magnet. For the stock mounting location the pocket should be deep enough so the magnet is flush with the outside of the plastic housing after assembly. -
Page 15: Mounting The Encoder
HOUSING. HAND TIGHTEN UNTIL RESISTANCE IS FELT. Figure 3.1.4.1. Figure 3.1.4.2. Note – Image shows a CTRE Mag Encoder, Figure 3.1.4.3. however CANCoder mounting is identical. Note – Image shows a CTRE Mag Encoder, however CANCoder mounting is identical. Cross The Road Electronics Page 15... -
Page 16: Verifying Magnet Placement
Once the CANCoder has been installed, magnet placement should be verified. A properly distanced magnet should result in a green LED at all speeds and positions. This test only requires the CANCoder to be powered. Wait 8 seconds after boot if CAN bus is not wired (to use the dim-rapid LED pattern - Section 1.5.1). -
Page 17: Vex Pro Single Speed Double Reduction Gearbox (217-2454)
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3.2. VEX PRO Single Speed Double Reduction Gearbox (217-2454) The output shaft of the VEX pro Gearbox has a .250” diameter extrusion located at the housing side of the gearbox Figure 3.2. This extrusion needs to be removed before boring the pocket that will house the magnet. The recommended tools for this procedure are: lathe, .250”... -
Page 18: Facing Off The Shaft End
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3.2.2. Facing Off The Shaft End Once the Extrusion has been removed, the end of the shaft will need to have a smooth even surface. This will make the following steps go smoother. Using a facing tool, turn the face of the shaft down until it is smooth and all of the remaining .250”... -
Page 19: Boring The Magnet Pocket
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 3.2.3. Boring the Magnet Pocket After the shaft has been faced, a pocket will need to be bored to house the magnet. The depth of this pocket is determined by the distance the encoder is located from the magnet. For the stock mounting location the pocket should be deep enough so the magnet is flush with the outside of the gearbox plastic housing after assembly. -
Page 20: Mounting The Encoder
HOUSING. HAND TIGHTEN UNTIL RESISTANCE IS FELT. Figure 3.2.4.2 Figure 3.2.4.1 Note – Image shows a CTRE Mag Encoder, however CANCoder mounting is identical. Figure 3.2.4.3 Note – Image shows a CTRE Mag Encoder, however CANCoder mounting is identical. Cross The Road Electronics... -
Page 21: Verifying Magnet Placement
Once the Encoder has been installed, magnet placement should be verified. A properly distanced magnet should result in a green LED at all speeds and positions. This test only requires the CANCoder to be powered. Wait 8 seconds after boot if CAN bus is not wired (to use the dim-rapid LED pattern - Section 1.5.1). -
Page 22: Faq
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 4. FAQ 4.1. Is there a way to tell if the sensor is present/powered? To determine visually if the sensor is powered and functioning, check the built-in LED, see Section 1.5. 5. Mechanical Drawings Cross The Road Electronics... -
Page 23: Errata
This prevents wires from passing through the housing as intended. Fix: If the housing included with your CANcoder has a too-long tab (as shown on the left of Figure 6.1.1), use diagonal cutters to cut the tab to the length shown on the right of Figure 6.1.1. -
Page 24: Revision History
CANCoder User’s Guide www.ctr-electronics.com 02/13/2023 7. Revision History Revision Date Description 02-Dec-2019 Initial Creation. 23-Jan-2020 Added Max RPM 31-March-2022 Added general specifications & LED Boot behavior 03-Nov-2022 Added Errata Section 13-Feb-2023 Added Phoenix Pro unlicensed LED state Cross The Road Electronics...
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