CTR Electronics CANdle User manual

CANdle User’s Guide www.ctr-electronics.com 1/17/2022
Cross The Road Electronics Page 1 1/17/2022
CANdle
User’s Guide
Revision 1.0
Cross The Road Electronics
www.ctr-electronics.com

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Table of Contents
1. Device description ........................................................................................................................................................................ 5
1.1. Common Use Cases............................................................................................................................................................... 5
1.2. Features ................................................................................................................................................................................ 6
1.3. Kit Contents........................................................................................................................................................................... 7
1.4. Electrical Specifications......................................................................................................................................................... 7
1.5. General specifications........................................................................................................................................................... 7
1.6. Onboard LED Specifications .................................................................................................................................................. 7
1.7. LED States ............................................................................................................................................................................. 8
2. Wiring ........................................................................................................................................................................................... 9
2.1. Wiring Diagram ..................................................................................................................................................................... 9
2.2. Enclosure Wire labels............................................................................................................................................................ 9
2.3. Individually Addressable LEDs............................................................................................................................................. 10
2.4. Powering a Raspberry Pi ..................................................................................................................................................... 11
2.5. Controlling a single-color LED ............................................................................................................................................. 12
2.6. Pixel Pulse Train Control - Separate Controller................................................................................................................... 13
2.7. Daisy Chain from Single Power Source................................................................................................................................ 14
3. Control Methods......................................................................................................................................................................... 15
3.1. Individually Addressable Control ........................................................................................................................................ 15
3.1.1. Individually Addressable Control –CAN bus ............................................................................................................... 15
3.1.2. Individually Addressable Control - WS2812B compliant pulse train ........................................................................... 15
3.2. On board LEDs and LED Order............................................................................................................................................. 15
3.3. CAN Single-Color Control .................................................................................................................................................... 15
4. Mounting .................................................................................................................................................................................... 16
4.1. Using the Spacers................................................................................................................................................................ 16
4.2. Panel Mounting................................................................................................................................................................... 17
5. External LED strip types .............................................................................................................................................................. 18
5.1. Testing Recommendations.................................................................................................................................................. 18
6. Phoenix Tuner / Phoenix Framework.......................................................................................................................................... 19
7. FAQ ............................................................................................................................................................................................. 20
7.1. Is there a way to tell if the device is present/powered?..................................................................................................... 20
7.2. How do I control LEDs? ....................................................................................................................................................... 20
7.3. How many LEDs can I drive from the CANdle?.................................................................................................................... 20
7.3.1. Software limiting LED count ........................................................................................................................................ 20
7.3.2. Current Draw limiting LED count................................................................................................................................. 20
7.4. Is the CANdle an LED strip or LED controller?..................................................................................................................... 20

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7.5. Do I need to set the RGB type for the onboard eight LEDs? ............................................................................................... 20
7.6. Can I power my Raspberry Pi or Jetson Nano from the CANdle?........................................................................................ 20
8. Mechanical Drawings.................................................................................................................................................................. 21
9. Revision History .......................................................................................................................................................................... 22

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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.
If you have any questions or comments regarding this document, or any CTRE product, please
contact supp[email protected]m
To obtain the most recent version of this document, please visit
www.ctr-electronics.com.

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1. Device description
The CANdle is a CAN-enabled individually addressable LED controller and a 5V high-efficiency DC voltage regulator
all in one compact device.
1.1. Common Use Cases
This device allows users to:
-Produce light using the eight individually addressable onboard LEDs - controlled via CAN bus (Phoenix) or
WS2812B-compliant pulse-train. Good for dome lamp applications.
-Control external individually addressable LEDs via CAN bus (Phoenix) or WS2812B-compliant pulse-train.
-Power a custom load using a 5V high-efficiency DC voltage regulator up to six amperes.
Great for Jetson Nano and other popular development boards!
-Measure output current, 5V voltage, and V+ input voltage.
-Enable/disable 5V output programmatically. (1)
-Modulate V+ output for single-color LEDs.
-Daisy-chain multiple CANdles using a single source of power.
Note 1: Not available without field-upgrade.
With all these use cases and features, the CANdle will likely find a place in a variety of your LED and voltage control
applications.

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1.2. Features
•Eight onboard individually addressable LEDs –CANdle can be used without wiring additional LEDs.
•Supports multiple kinds of external addressable LEDs (1)
•Works with 12V RGB(W) LED strips (when +VIN is ~12V)
•Works with 5V RGB(W) LED strips (using onboard regulated 5V supply)
•5V Output can also power 5V peripherals such as Raspberry Pi or Jetson Nano
•Reverse Input Power Protection
•Output Short Circuit Protection
•Output Overcurrent Protection
•Thermal Protection
•Voltage and Current Measurement
•High-Side PWM control of the V+ Output
•Polycarbonate housing prevents debris from entering inside device
•Electrically isolated heatsink allows for direct mounting to robot frame
•Auto-detection of CAN bus / CAN FD (Phoenix) or WS2812B-compliant pulse-train.
No software configuration required to choose between the two.
•Robust bootloader and reliable field-upgrade (no physical button required, no “stuck states”that
requires user intervention)
•Firmware supports several animations (Larson, rainbow, twinkle, color fades, etc.) when used with CAN
bus
•Robust embedded wire leads that will not shake loose.
•Wire leads are labeled for fast and easy wiring.
Note 1: See Section 5 for more information on what types of individually addressable LEDs are supported.

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1.3. Kit Contents
The kit contains a single CANdle and two aluminum
spacers.
Note: External LED strip is not included, however LED
strips may be purchased at ctr-electronics.com.
Note: CANdle has eight onboard individually addressable
LEDs. This means CANdle can be illuminated without
wiring additional LEDs.
1.4. Electrical Specifications
Symbol
Parameter
Condition
Min
Typ.
Max
Unit
Tamb
Ambient temperature
-40
+85
°C
IQ
Quiescent Supply Current
DC supply 12.0V
50
60
mA
+VIN
Supply voltage
6.0
12.0
28.0
V
-IOUT
Current sunk thru -VOUT
0
6
A
IMAX
Maximum Output Current
Sunk via -Vout
6
A
ESD Rating
ESD Protection Contact Discharge
±30
kV
ESD Protection Air-Gap Discharge
±30
kV
1.5. General specifications
Outside Dimensions
2.7” x 1”
Weight (with wires)
1.584 ounces (44.9 grams)
Supported Communication Protocols
CAN 2.0 (1Mbps)
CAN FD when used with CANivore
Addressable LED Pulse Train
Maximum Operational Temperature @ 5 A(1)
75 °C
Maximum Operational Temperature @ 5 A(2)
55 °C
NOTE 1: This is the maximum expected temperature CANdle can reach when sourcing 5 amps continuously, without any additional heat sink attached
NOTE 2: This is the maximum expected temperature CANdle can reach when sourcing 5 amps continuously, while attached to a heat sink via the provided spacers,
shown in Section 4.1 Using the Spacers.
1.6. Onboard LED Specifications
Parameter
Min
Typ.
Max
Unit
Number of onboard LEDs
8
Red Intensity
700
1000
mcd
Green Intensity
1500
2200
mcd
Blue Intensity
700
1000
mcd
Red Wavelength
625
nm
Green Wavelength
520
nm
Blue Wavelength
470
nm

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1.7. LED States
The CANdle features a tri-color LED that indicates CAN bus health and general status (similar to other CTR-
Electronics CAN devices). This feature can be used to confirm proper CAN bus and power wiring. The table below
shows the possible color patterns and their respective CANdle states.
LED Color
5V out / V+ out
Description
Off
Disabled
CANdle is not powered/ plugged in.
Check power cabling to the CANdle.
Also confirm software configuration has not disabled LED
explicitly. (Note 1)
Yellow/Green
(LED is never off)
Disabled
Device is in bootloader, most likely because field-upgrade failed
in middle of event.
Inspect CAN bus wiring and re-field-upgrade using Phoenix Tuner.
If device has valid firmware, turn device off, wait 10 seconds, and
turn device on to boot strap it.
In this state, the 5V and V+ outputs are off to prevent accidental
shorting.
Red/Yellow
(LED is never off)
Disabled
(…if firmware determines
this is required)
Hardware is damaged.
Slow Red Blink
Configurable/On (Note 2)
Check CAN Bus health and connection to the CANdle/Pixel pulse
train connection to the CANdle.
In this state, the output of the CANdle is determined by
configuration.
Rapid Red Blink
Off
Device has faulted and has disabled outputs to prevent hardware
damage.
Check Phoenix Tuner self-test to diagnose what fault occurred.
Check wiring to ensure no shorts across output leads.
Yellow Blink
Configurable/On (Note 2)
CAN bus detected but no commands are being received. Most
likely no CANdle object created in software.
Green Blink
Configurable/On (Note 2)
CANdle is actively controlled either via CAN or through the pixel
pulse train.
Note 1: Software configuration allows customers to turn off tri-color LED when loss of signal occurs (CAN bus or pulse-train) as some applications
may require absolutely no light when disconnected. In such a case, consider this as a potential cause of why the LED is off.
Note 2: The outputs are controlled by software configuration.

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2. Wiring
Due to the sealed nature of the CANdle, all wires leads are pre-installed. Because of this, customers can use whatever
connector solution is required for the application.
The wiring details will be determined by the desired use case of the CANdle. As a result this section documents several wiring
diagrams for each use-case.
2.1. Wiring Diagram
Color of wire
Signal
Description
Inputs to CANdle
Red (18 AWG)
+VIN
The supply input voltage (6 V –28 V, typically 12 V)
Black (18 AWG)
-VIN
The supply ground (0 V)
Yellow (22 AWG)
CANH (Note 1)
CAN Bus High
Green (22 AWG)
CANL (Note 2)
CAN Bus Low
Outputs from CANdle
Blue (18 AWG)
5VOUT
Regulated 5V for powering 5V addressable LEDs or 5V
development boards.
Orange (18 AWG)
+VOUT
Provides voltage to LEDs that are rated for supply
voltage. This can be modulated via software.
A common use case is to power CANdle with 12V lead
acid battery, and use +VOUT to power 12V LEDs.
Use +VOUT to power 12V LED strips. (Note 3)
Do not use +VIN to power 12V LED strips.(Note 3)
White (18 AWG)
DOUT
WS2812B compliant signal for individually addressable
LEDs.
Gray (18 AWG)
-VOUT
Ground reference for all outputs.
Do not use -VIN to sink load currents.
Note 1: Both CANH wires are electrically common.
Note 2: Both CANL wires are electrically common.
Note 3: CANdle safely disables +VOUT and 5VOUT during fault conditions.
Therefore, these must be used to power outputs for safe operation.
2.2. Enclosure Wire labels
Wire leads labels are available on the back of heatsink. This makes wiring the CANdle even easier.

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2.3. Individually Addressable LEDs
The output leads must be used to control individually addressable LEDs.
5V addressable LEDs must use the +5V rail.
12V addressable LEDs must use the +Vout rail.
Ground return must use -VOUT.
Do not connect +VIN or -VIN to the LED strip.
The example below demonstrates wiring an external 5V LED strip.

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2.4. Powering a Raspberry Pi
CANdle can be used to power custom 5V devices such development boards.
This allows customers to leverage the power control and monitoring features of CANdle when using a Raspberry Pi subsystem.
Do not connect +VIN or -VIN to the load.

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2.5. Controlling a single-color LED
Single-color non-addressable LED strips that simply take direct voltage are also supported with CANdle. These LEDs are not
individually addressable –meaning all LEDs will increase with brightness as the output intensifies.
For such LEDs, connect +VOUT and -VOUT to the LEDs.
Do not connect +VIN or -VIN to the LED strip.
The LEDs must be rated for the same voltage wired to CANdle via +VIN.
If CANdle is wired to ~12V source, the LEDs must be able to withstand the same voltage.

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2.6. Pixel Pulse Train Control - Separate Controller
The previous wiring sections demonstrate control and monitoring via the CAN bus wires.
However, CANdle can also auto-detect a WS2812B-compliant pulse-train from common generators such as the Arduino.
No software configuration is required by CANdle for this, simply wire CANH to the pulse-train signal, and CANL to the logic
ground of the signal generator.

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2.7. Daisy Chain from Single Power Source
Additionally, a supplemental CANdle can be powered “down-stream”of another CANdle. Note that this will increase the
current draw of the “up-stream”CANdle.

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3. Control Methods
3.1. Individually Addressable Control
There are two methods for controlling individually addressable LEDs. This includes both the eight onboard LEDs and external
LEDs (if wired by the user).
Note that in both circumstances, LED index 0 –7 controls the first eight LEDS. LED index 8 and on reference the external LEDs.
See Section 3.2. for more information on LED order.
3.1.1. Individually Addressable Control –CAN bus
CANdle can control individually addressable LEDs by receiving commands from the CAN bus. Controlling CANdle in this manner
requires use of CTR Electronics’ Phoenix API, available for download here: ctr-electronics.com/software.
This allows customers to:
-request pre-written multi-LED animations with a single command
-or direct control each LED manually
3.1.2. Individually Addressable Control - WS2812B compliant pulse train
Individually addressable LEDs can also be controlled by a WS2812B-compliant pulse-train. Connect the pulse train signal to
CANH (yellow) and connect the signal generator’s ground reference to CANL (green).
The CANdle will still provide power to the downstream LEDs, allowing system developers to only be concerned about color
control.
Note that the pixel pulse train still controls the onboard LEDs. The first eight onboard LEDs are first on the data chain, then the
ninth LED index will be the first LED on the external LED strip.
For information on the onboard LEDs, see Section 6. On board LEDs.
3.2. On board LEDs and LED Order
The LEDs are sequenced in order as depicted below:
3.3. CAN Single-Color Control
CANdle can also control brightness of single-color LEDs by modulating the supply voltage (via +VOUT).
This feature requires using CAN bus and Phoenix API.

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4. Mounting
The CANdle allows for multiple methods of mounting, two of which are described below.
4.1. Using the Spacers
The CANdle can be mounted using the provided spacers. This allows clearance for the wires to travel out under the heatsink.
This is a particularly convenient method of mounting the CANdle, as it only requires a flat surface to drill holes into and
subsequently mount against.

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4.2. Panel Mounting
CANdle can also be panel mounted. This requires milling out a hole so that the front face (LED side) can be fitted through.
Refer to Section 8 for mechanical dimensions.

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5. External LED strip types
There are multiple types of individually addressable LEDs that affect how color is encoded.
When using external LED strips, it is essential to configure the correct type of LED to get the desired effects.
CANdle supports the following three color (24 bit pixel) types:
•GRB –First byte is Green, second byte is Red, third is Blue (default configuration)
•RGB –First byte is Red, second byte is Green, third is Blue
•BRG –First byte is Blue, second byte is Red, third is Green
CANdle supports the following four color (32 bit pixel) types:
•GRBW –First byte is Green, second byte is Red, third is Blue, fourth is White
•RGBW –First byte is Red, second byte is Green, third is Blue, fourth is White
•GRBW –First byte is Blue, second byte is Red, third is Green, fourth is White
Failure to properly configure the LED type will result in incorrect colors.
5.1. Testing Recommendations
The primary recommendation is to confirm the LED type by referencing the documentation of the LED strip.
All LED strips sold by CTR-Electronics have such documentation available on the product pages at https://ctr-electronics.com.
But if documentation is not available, the easiest way to configure an unknown LED strip is to drive a single solid color (solid
red for example). If external LEDs illuminate a different solid color, adjust configuration until red appears. Repeat for green
and blue.
If requesting a solid color produces several colors to appear on the LEDs, then the LED strip likely uses 32 bit pixels (with
separate white component) whereas CANdle is configured for three colors (no white component) or vice versa.

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6. Phoenix Tuner / Phoenix Framework
Like all CAN bus devices from CTR-Electronics, CANdle is supported in Phoenix Framework.
CANdle is supported in Phoenix Tuner. This allows
for fast and efficient debugging of your robot
platform
Configuration changes can be done in
the graphical interface quickly before
incorporating them into your robot
application.
The Phoenix library also supports the CANdle class, allowing
for configuration, monitoring, and control of your CANdle
from your robot software.
Additional software documentation will be available under
the Phoenix Framework documentation section under
https://ctr-electronics.com/documentation

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7. FAQ
7.1. Is there a way to tell if the device is present/powered?
To determine visually if the sensor is powered and functioning, check the built-in tri-color status LED, see Section 1.7.
7.2. How do I control LEDs?
The CANdle and respective LEDs can be controlled either by the CAN bus or through an external controller generating a pixel
pulse train. For more information on the ways to control the CANdle, see Section 3.
Additionally, the choice of how to control the LEDs will determine the wiring as explained in Section 2.
7.3. How many LEDs can I drive from the CANdle?
There are two factors that determine how many LEDs a CANdle can control. Both are covered in sections below.
7.3.1. Software limiting LED count
There is no software limit when LEDs are controlled via WS2812B-compliant pulse-train (through CAN wires).
However, firmware limits the maximum number of LEDs to 400 when controlled over CAN bus.
If this is adjusted in future firmware releases, this can be confirmed in Phoenix Tuner self-test.
7.3.2. Current Draw limiting LED count
The CANdle can supply up to IMAX of total current (combined return current from the 5VOUT and +VOUT rail).
Note the return current must be sunk through -VOUT.
Typically, this is sufficient for 300 GRB LEDs at max brightness.
Exceeding this may cause LEDs to appear dim or will cause CANdle to fault if current exceeds IMAX.
Limiting the brightness of the CANdle can be used to reduce the total current draw, thus allowing for more LEDs.
7.4. Is the CANdle an LED strip or LED controller?
The CANdle is both an LED strip and an LED controller. The first eight addressable LEDs are onboard and integrated. The first
extern LED added via the wire leads is considered the “ninth” addressable LED. This will be references as index ‘8’in software.
7.5. Do I need to set the RGB type for the onboard eight LEDs?
No, the CANdle firmware already compensates for the RGB color type of the onboard LEDs.
You can select any external LED strip type that matches the available types in Section 5.
7.6. Can I power my Raspberry Pi or Jetson Nano from the CANdle?
Yes, CANdle can power (non-inductive) loads that rated for 5V and no more than 6amps. Both products in their default
configuration require less than 6 amps, and so can be powered by the CANdle. If you are adding peripherals to a co-processor,
factor in the current consumption of that co-processor and determine if the total current budget is sufficient for a CANdle to
supply. A wiring diagram in Section 2.4 shows how to wire the CANdle to power a Raspberry Pi.