HEBI Robotics | Documentation

Hardware

This section contains information specific to different hardware products and accessories. This includes information on modules and actuators, mechanical and electical accessories, robot kits, and details of any hardware-specific parameters for the APIs.

CAD files of the actuators and accessories are available at cad.hebi.us.

Modules

HEBI modules are ethernet-enabled devices that serve as building blocks for a robot or automated system. These modules include actuators to provide physical motion, and devices to interface with other sensors and I/O. Modules run firmware that allow them to communicate over a standard ethernet connection. Aspects of the firmware that are common to all modules are documented in Core Concepts, while aspects that are module-specific are documented below.

T-Series & R-Series Actuators

R-Series_Actuators

The T-Series and R-Series Actuators are 'smart' series-elastic actuators that integrate a brushless motor, geartrain, spring, encoders, and control electronics into a compact package that run on standard DC voltages and communicate using standard 10/100Mbps Ethernet over plastic optical fiber (POF). These actuators are designed to function as full-featured robotic components and enable the simultaneous control of position, velocity, and torque. Each actuator also has a wide range of other sensors, all of which can be easily accessed in the the various APIs. The T-Series Actuators are great for everyday robotics research and indoor robotics systems whereas, the R-Series Actuators are sealed to IP67 that allows them to be used in challenging field applications.

The X-Series section has been removed. The charts and information below for the T5 and T8 Actuators can be directly correlated to the corresponding X-Series Actuators.

Maximum Performance Range

The chart below indicates, separately, the maximum no-load speed and stall torque capabilities of the different models of T-Series and R-Series actuators.

For example, an R8-9 is not capable of continuously providing 9 Nm of torque at 30 RPM. It is capable of a continuously spinning at maximum speed of 30 RPM at a lower torque, and it is capable of exerting 9 Nm of torque at a lower speed.

More detailed performance information for each actuator is provided in the additional sections below.

Speed-Torque Curves

Each actuator has a range where it can perform continuously, as well as a peak range where it can perform intermittently. While T-Series and R-Series actuators are rated running at 24V, they are capable of increased intermittent output at higher voltages.

The speed-torque curves below show both the continuous and intermittent operating ranges at 24V, as well as 36V and above. While the actuators can be run at bus voltages up to 48V, the performance is limited in firmware to the equivalent to 36V, allowing safe operation while decreasing the amount of current drawn at the power bus. The ranges shown below are approximate and assume an actuator in normal room-temperature conditions without additional cooling.

Frequency Response (Bode Plots)

Because the T-Series and R-Series actuators are mechanically compliant, there is a limit to how rapidly they can react and track to desired commands. Overall, the actuators are designed to be able to replicate human-like motion, but the details of their frequency response depends on the model of the actuator and the details of its commanded action.

The plots below were generated with a mechanically fixed output and tracking a sinusoidal commanded effort of different amplitudes. The ranges shown below are approximate and assume an actuator running at 36V in normal room-temperature conditions without additional cooling. The gains that are used when controlling an actuator greatly effects the frequency response. The plots below use an effort Kp approximately 2X the default value that ships with a new actuator.

Mechanical Information

Actuator Model	Gear Ratio	Spring Stiffness (Non-Linear)	Output Bearing Capacity
T5-1	272.222 : 1	Min: ~10 Nm / rad Max: ~50 Nm / rad	Radial Load Rating Static: 2.2 kN Dynamic: 3.0 kN Axial Load Rating Static: 5.1 kN Dynamic: 6.9 kN Cross-Moment Load Rating Static: 55.6 Nm Dynamic: 75.5 Nm
T5-4	762.222 : 1	Min: ~20 Nm / rad Max: ~200 Nm / rad
T5-9	1742.222 : 1	Min: ~50 Nm / rad Max: ~500 Nm / rad
T8-3 / T8-3+ R8-3 / R8-3+	272.222 : 1	Min: ~50 Nm / rad Max: ~150 Nm / rad
T8-9 / T8-9+ R8-9 / R8-9+	762.222 : 1	Min: ~70 Nm / rad Max: ~700 Nm / rad
T8-16 / T8-16+ R8-16 / R8-16+	1462.222 : 1	Min: ~140 Nm / rad Max: ~1400 Nm / rad
T25-8 / R25-8	253.657 : 1	Min: ~100 Nm / rad Max: ~5000 Nm / rad	Radial Load Rating Static: 2.8 kN Dynamic: 4.7 kN Axial Load Rating Static: 5.6 kN Dynamic: 9.4 kN Cross-Moment Load Rating Static: 105 Nm Dynamic: 175 Nm
T25-20 / R25-20	638.682 : 1
T25-40 / R25-40	1301.345 : 1

Electrical / Motor Information

Actuator Model	Approximate Torque Constant	Approximate Speed Constant	Motor Winding Resistance	Motor Inertia	Gear Inertia @ Motor
T5-1	1.1 Nm / A	5.6 RPM / V	10.0 Ω	43 gmm^2	18 gmm^2
T5-4	3.1 Nm / A	2.0 RPM / V			16 gmm^2
T5-9	7.1 Nm / A	0.9 RPM / V			15 gmm^2
T8-3 R8-3	1.6 Nm / A	3.8 RPM / V	5.3 Ω	85 gmm^2	11 gmm^2
T8-9 R8-9	4.6 Nm / A	1.3 RPM / V			6 gmm^2
T8-16 R8-16	8.8 Nm / A	0.7 RPM / V			5 gmm^2
T8-3+ R8-3+	1.8 Nm / A	3.8 RPM / V	3.0 Ω	60 gmm^2	11 gmm^2
T8-9+ R8-9+	5.1 Nm / A	1.3 RPM / V			6 gmm^2
T8-16+ R8-16+	9.8 Nm / A	0.7 RPM / V			5 gmm^2
T25-8 R25-8	1.6 Nm / A	4.2 RPM / V	0.5 Ω	364 gmm^2
T25-20 R25-20	4.0 Nm / A	1.7 RPM / V
T25-40 R25-40	8.2 Nm / A	0.8 RPM / V

EMC Certifications

Actuator Series	Certifications	Declarations of Conformity
T-Series	FCC Part 15 EN 55022 CISPR 22 EN 61000	T5 - CE Mark DoC T5 - FCC SDoC T8 - CE Mark DoC T8 - FCC SDoC
R-Series	FCC Part 15 IC ICES-003 IEC 61000-6-4:2011 IEC 61000-6-2:2005 EN 55011:2009	R8 - CE Mark DoC R8 - FCC SDoC
X-Series	FCC Part 15 ICES-003 EMC Directive 2014/30/EU	N/A

Reference Frames

The reference frames for the T-Series and R-Series Actuators are shown in the images below. The origin of the coordinate frames are on the back plane of the housing, centered on the axis of rotation. This is the frame in which the IMU feedback is reported, and it is also the frame that is used for kinematics calculations in the various APIs and the HRDF file format. The coordinate frames are also physically engraved on the housing of each actuator.

T ref frames R8 ref frames

Default gains (T-Series & R-Series)

We have provided downloadable recommended default gains for all control strategies of each of our T-Series and R-Series modules. Note that these gains should still be tuned for best performance depending on the particular application. For almost all applications we recommend using Strategy 4.

Module Type	Strategy 4 (recommended)	Strategy 3	Strategy 2
T5-1	T5-1, Strategy 4	T5-1, Strategy 3	T5-1, Strategy 2
T5-4	T5-4, Strategy 4	T5-4, Strategy 3	T5-4, Strategy 2
T5-9	T5-9, Strategy 4	T5-9, Strategy 3	T5-9, Strategy 2
T8-3 / T8-3+ R8-3 / R8-3+	T8-3 / R8-3, Strategy 4	T8-3 / R8-3, Strategy 3	T8-3 / R8-3, Strategy 2
T8-9 / T8-9+ R8-9 / R8-9+	T8-9 / R8-9, Strategy 4	T8-9 / R8-9, Strategy 3	T8-9 / R8-9, Strategy 2
T8-16 / T8-16+ R8-16 / R8-16+	T8-16 / R8-16, Strategy 4	T8-16 / R8-16, Strategy 3	T8-16 / R8-16, Strategy 2
T25-8 / R25-8	T25-8 / R25-8, Strategy 4
T25-20 / R25-20	T25-20 / R25-20, Strategy 4
T25-40 / R25-40	T25-40 / R25-40, Strategy 4

Wiring

T-Series and R-Series actuators were designed to simplify traditional wiring pain points and wire loops by incorporating a through hole. A multi-port switch for daisy chaining POF communication as well as a terminal block for power daisy chaining.

Wiring Block Diagram

Here is a simple Block Diagram showing the wiring setup for the T-Series and R-Series Actuators. All electronics shall be used with a 24-48V power supply. The communications runs off of 100 Mbps Ethernet converted in the Media Converter to plastic optical fiber (POF) into the actuator.

A POF-Ethernet Media Converter is used to connect the T-Series and R-Series Actuators to the network. The converter can run off the same 24-48VDC as the actuators and can convert 100 Mbps RJ45 Ethernet communication to 2.2mm plastic optical fiber (POF) communication of the same 100 Mbps Ethernet.

T-Series Wire Seals

Wires need to be fed thru wire seals for best sealing (~IP64).	Power wires connect to the green terminal block which has 2 ports for each cable enabling daisy-chaining.
There are two OptoLock® connectors for POF communication chaining.	Fully close the back of the T-Series. There is a retaining feature on the connector cover that will keep the power block from being accidentally pulled out during use.

R-Series Cord Grips

Wires need to be fed thru cord grips for sealing.	Power wires connect to the green terminal block which has 2 ports for each cable enabling daisy-chaining.
There are two OptoLock® connectors for POF communication chaining.	It is best to group the six cables for Power, M-Stop, and POF in the same cord grip to make routing wires more organized.

M-Stop Wiring

An M-Stop (motor-stop) button can be wired to the T-Series and R-Series Actuators' terminal plug for additional safety. We recommend using a lower voltage (5V) to power the M-Stop for reduced power dissipation. Below are examples of how the MS+ and MS- lines can be wired if you want to use an M-Stop Button in your system:

M-Stop connected to a lower voltage source to reduce power dissipation (preferred configuration).
M-Stop connected to same power supply as the actuator.

The MS+ and MS- lines are the "M-Stop" input for the Actuators. They correspond to the "M-Stop Strategy" setting on the actuators that can be selected from the Scope Application on the 'Gains' Tab shown in the screenshot below:

The actuators can be set to have different behaviors when the M-Stop is triggered, described in the table below.

Make sure to use the "Persist Sends" option when setting the M-Stop Strategy in order to maintain setting after actuator the actuator is reset or turned off and on.

M-Stop Strategy	Description
Disabled	The M-Stop input is ignored. The actuator runs normally no matter what voltage is applied to these lines.
Motor Off	The M-Stop pins require voltage (5V-48VDC) for the actuator to run. When voltage is removed, the motor in the actuator is deactivated (set to Control Strategy Off) and the actuator is backdrivable. The status LED will blink yellow.
Motor Hold	The M-Stop pins require voltage (5V-48VDC) for the actuator to run. When voltage is removed, the motor in the actuator is controlled to maintain its current position. The status LED will blink yellow.

Mechanically Mounting Actuators

The T-Series and R-Series Actuators have threaded holes for M5 metric screws on their output and bottom sides and four M3 threaded holes on the front plate for mounting. Additionally, there are two 3mm Dowel Pin holes that are spaced 35mm apart symmetric from the center bore on both the output and input interfaces to help with bracket alignment. If you are using standard HEBI connection parts, the appropriate hardware is provided.

Check out the standard T-Series & R-Series Accessories

T5 Reference Drawing: T5 Dimensional Interface Drawing

T8 Reference Drawing: T8 Dimensional Interface Drawing

R8 Reference Drawing: R8 Dimensional Interface Drawing

Be careful to use the appropriate length screws when mounting the actuators. Using screws that are too long may damage the actuator if they are tightened while bottomed out in the threaded holes.

Be sure to only use Stainless Steel or other Corrosion-Resistant hardware with the R-Series Actuators. This is to prevent the hardware from seizing due to corrosion.

Sealing R-Series Actuators

The R-Series actuators are designed to be sealed to an IP67 rating. In order to achieve the seal, the connector cover needs to be fully installed to the back end of the Actuator.

The connector covers (A-2204-01A and A-2204-01B) have an o-ring that will seal against the back of the actuator. Using the silicone grease in the connection toolbox, fully grease the o-ring before attaching the cover.

If only one cord grip has wires coming through it, replace the unused cord grip insert with a solid plug (PP-2408-01) and tighten down the cord grip.

solidPlugSeal connector cover screws cord grip tighten

Lightly pull the slack in the cables through the cord grips to bring the connector cover up agaisnt the actuator. Make sure the terminal block does not disconnect from the actuator.
While holding the connector cover up against the actuator, screw down the captive M3 bolts.
Use a 19mm (or 3/4") open wrench to tighten down the cord grip rubber insert around the wires.

It is important to note that the media converter and other electronics, like the power supply, are not sealed. Make sure there is enough cable length to keep the electronics in some kind of protective case or box if the actuators are being used in a dirty or wet environment.

Internal Pressure (R-Series)

In addition to being sealed for intermittent wet use, R-Series actuators contain an internal pressure sensor that can be accessed on the pressure in the actuator feedback.

Readings are in kPa

The readings from the sensor are absolute pressure, which is the sum of gauge pressure and atmospheric pressure. The reading of an unpressurized actuator will fluctuate slightly with changes atmospheric pressure and temperature.

Standard Reading: ~101 kPa (1 atm or 14.7 psi)
Minimum Internal Pressure : 10 kPa (1.5 psi)
Maximum Internal Pressure : 300 kPa (43.5 psi)

Include a valve

When you are internally pressurizing R-Series actuators it is always good to have some kind of valve incorporated for adding and removing air from the system.

Remember to remove all internal pressure from actuators before disassemblying wiring of actuators. This includes prior to loosening cord grips and screws on connector covers. This will prevent causing harm to yourself or damage to actuator’s o-rings and other components.

In most cases it is best to use the M-stop (blue and yellow) wiring, but if you determine you don’t need it, then you can always loop a wire in the last 2 open cord grip holes to keep the Actuator sealed (shown in image below).

r series air in r series two air in

Plug the last Cord Grip with Solid Wire

Even though the R-Series actuators are sealed, air is still able to pass through the wiring of the actuators. Whether you are pressurizing a single or multiple actuators, the last cord grip in your chain should use solid core wire for the power and M-stop lines. This will prevent air from escaping from the pressurized system.

We recommend using the following solid core wires:

Black 18AWG Solid Core Wire: Alpha Wire 6715S BK005
Red 18AWG Solid Core Wire: Alpha Wire 6715S RD005

Solid core wires work well with the WAGO wire nuts and a standard HEBI flying-lead power cable (both included in R-Series standard wiring kit).

Alternative method: custom tether pressurization adapter

As an alternative experiment, a group of 5 actuators were daisy-chained together using the standing wiring cables and a tether pressurization adapter. This custom adapter allows for pressure to be added to the system from the tether instead of the end effector actuator and prevents air from escaping back to your power supply with solid core wire.

A constant air supply of ~250 kPa (absolute pressure) was supplied from the tether with the last module having a solid plug.

The following plots show the difference between using using only stranded wires and using the solid core wires in from the tether pressization adapter.

The POF (plastic optical fiber) cables fully block air flow and do not need to be changed.

From the plot on the left, the pressure drop between actuators in steady-state appears to be correlated to length of wire between the two actuators. The longer the wires, the larger the pressure drop. Additionally, pressure and temperature are directly proportional, as the actuator temperature increases the internal pressure will also increase.

Actuator Feedback

All actuators (both X-Series and R-Series) provide all the feedback below when feedback is requested. Feedback can be requested at rates up to 1 kHz. Wherever possible values are in SI units.

Parameter	Units	Description
`time`	`sec`	The current time from the system clock used by the API. This is a single value that corresponds to all feedback at this timestep.
`pcRxTime`	`sec`	The system time when feedback was received by each module. The most recent of these times is what is reported as the single `time` above.
`pcTxTime`	`sec`	The system time when feedback requests were sent to each module.
`hwRxTime`	`sec`	The hardware timestamp when each module in the group transmitted its feedback. Time initializes at 0 when a module is powered on.
`hwTxTime`	`sec`	The hardware timestamp when each module in the group received a request for feedback. Time initializes at 0 when a module is powered on.

`position`	`rad` or `m`	Sensed position (absolute) of the output of an actuator. T-Series and R-Series Note: The output encoder in these actuators is multi-turn absolute to +/- 4 rotations (8 x 360-degree total range). The encoder knows its position within this range immediately when powering on, even if the actuator is moved while it is not powered. Once the actuator is powered on, it reports its position continuously and unlimited in either direction. If you go outside the +/- 4 rotation range and restart the actuator, the reported position from the encoder will ‘wrap around’ and initialize within +/- 4 rotations.
`velocity`	`rad/sec` or `m/sec`	Sensed velocity at the output of an actuator.
`effort`	`Nm` or `N`	Sensed force or torque (absolute) at the output of an actuator.

`positionCmd`	`rad` or `m`	The currently commanded `position`. If no position is being commanded a value of `NaN` is returned.
`velocityCmd`	`rad/sec` or `m/sec`	The currently commanded `velocity`. If no velocity is being commanded a value of `NaN` is returned.
`effortCmd`	`Nm` or `N`	The currently commanded `effort`. In control `STRATEGY_2`, `3` or `4`, this is a commanded torque or force. In `DIRECT_PWM` mode, this is the commanded `PWM` to an actuator’s motor. If no effort is being commanded a value of `NaN` is returned.
`innerEffortCmd`	`Nm` or `N`	In control strategies 2 and 4, this is the torque or force command going to the inner torque PID loop.
`pwmCmd`	`-1 to 1`	The currently commanded `PWM` being sent to an actuator’s motor, after being modified by any internal safety controllers.

`deflection`	`rad`	The internal deflection of the spring inside an actuator. This value is used with a calibrated spring constant in each actuator to report the actuator’s `effort` feedback.
`deflectionVelocity`	`rad/sec`	The velocity of the internal spring’s deflection.
`motorPosition`	`rad`	The position of an actuator’s internal motor before the gear reduction. Initializes at zero when an actuator is first powered on.
`motorVelocity`	`rad/sec`	The velocity an actuator’s internal motor before the gear reduction.

`accel` or `accelX` `accelY` `accelZ`	`m/sec^2`	A module’s sensed 3-DoF acceleration from an internal IMU, including gravity. Note that this is the sensed motion of the actuator body itself, not the actuator’s output. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`gyro` or `gyroX` `gyroY` `gyroZ`	`rad/sec`	A module’s sensed 3-DoF angular velocity from an internal IMU. Note that this is the sensed motion of the actuator body itself, not the actuator’s output. Depending on the API, XYZ values are combined together into a single vector or returned individually.
`orientation` or `orientationW` `orientationX` `orientationY` `orientationZ`	`unit quaternion`	A module’s 3-DoF orientation based on an onboard complementary filter. The heading component of the estimated orientation will drift over time, as the filter uses only accelerometers and gyros. Depending on the API, quaternion components are combined together into a single vector or returned individually.

`motorCurrent`	`A`	The sensed amount of current an actuator’s motor draws at the bus voltage.
`windingCurrent` or `motorWindingCurrent`	`A`	The estimated of amount current draw of the motor windings internal to the actuator. This value is modeled based on the known motor parameters, internal motor velocity, and current.
`voltage`	`V`	The sensed bus voltage into the module.

`motorTemperature` or `motorSensorTemperature`	`deg-C`	The sensed temperature near the motor in the actuator.
`ambientTemperature` or `boardTemperature`	`deg-C`	The sensed temperature of the electronics in the actuator.
`processorTemperature`	`deg-C`	The sensed temperature of the processor in the actuator.
`actuatorTemperature` or `motorHousingTemperature`	`deg-C`	The modeled housing temperature of the motor inside an actuator.
`windingTemperature` or `motorWindingTemperature`	`deg-C`	The modeled winding temperature of the motor inside an actuator. This value is used by a safety controller that runs in the firmware of an actuator that will limit the `PWM` to the motor if it approaches a critical temperature.

`mStopState`	`enum` or `HebiEnum.MStopState*`	The status of the M-Stop line in the module. `not triggered` `triggered`
`commandLockState`	`enum` or `HebiEnum.CommandLockState*`	The status of the command lockout on the module, active during the `CommandLifetime` of a given command. `not locked (ready to receive commands)` `locked by sender (receiving commands from this group)` `locked by other (commands from this group will be ignored)`
`temperatureState`	`enum` or `HebiEnum.TemperatureState*`	The status of the various temperature safety controllers on the module. `normal` `critical` `exceeds maximum motor temperature` `exceeds maximum board temperature`
`positionLimitState` `velocityLimitState` `effortLimitState`	`enum` or `HebiEnum.PositionLimitState*`	The status of the various motion safety controllers on an actuator. `below lower limit` `at lower limit` `inside range (normal operation)` `at upper limit` `above upper limit` `not initialized`

`LED` or `ledR` `ledG` `ledB`	`0 to 1`	RGB color values of the status LED. Depending on the API, RGB values are combined together into a single vector or returned individually.

`pressure`	`kPa`	Internal absolute pressure of the actuator in kPa. (R-Series Only)

Actuator Commands

The typical actuator commands for controlling motion are the same as the commands listed in the Groups section of Core Concepts. Additionally, there are direct commands for PWM and FOC current/voltage that are sometimes used in research-focused applications.

Parameter	Units	Description
`position`	`rad` or `m`	The desired position of the output of an actuator.
`velocity`	`rad/sec` or `m/sec`	The desired velocity of the output of an actuator.
`effort`	`Nm` or `N`	The desired torque or force of the output of an actuator. For an actuator in the `DIRECT_PWM` control strategy, this will be the desired `PWM` of the motor, from `-1 to 1`. This control is deprecated and may be removed in future APIs. For direct PWM control use the `PWM` command detailed below.

`PWM`	`-1 to 1`	For an actuator in the `DIRECT_PWM` control strategy, this will be the desired `PWM` of the motor, from `-1 to 1`.

`focIq` `focId`	`A`	For an actuator in the `DIRECT_FOC` control strategy, this will be the desired DC-equivalent motor current in Amps.
`focVq` `focVd`	`V`	For an actuator in the `DIRECT_FOC` control strategy, this will be the desired DC-equivalent motor voltage in Volts.

In addition to commands related to motion, a number of hardware-specific parameters can be commanded and/or set.

Parameter	Units	Description
`name`	`string`	The desired user-settable name that an actuator shows up as in a `Lookup`.
`family`	`string`	The desired user-settable family that an actuator shows up as in a `Lookup`.

`boot`	`boolean`	Boots a module from bootloader mode into application mode.
`reset`	`boolean`	Reboots a module.
`persist`	`boolean`	Saves all the settings and gains that are currently set on a module, so that they are loaded after reboot.

`gains`		All controller parameters are settable in the API. See Parameters and Gains in the Core Concepts section for more information.

`referencePosition`	`rad` or `m`	Sets the current feedback `position` by adjusting the user-settable reference point for the zero position. This persists automatically.
`referenceEffort`	`Nm` or `N`	Sets the current `feedback` effort by adjusting the user-settable reference point for zero effort. This persists automatically.

`ledR` `ledG` `ledB`	`0 to 1`	Override RGB color values of the status LED.

I/O Board

pcba 2075 01 front pcba 2075 01 back

The HEBI I/O Board is an ethernet-enabled module that allows you to easily integrate various low-level sensors into HEBI’s APIs and framework. This module provides general-purpose analog and digital inputs, digital and PWM outputs, encoder inputs, and exposes in the various HEBI APIs in a way that is syncronized with any other modules on the network. It also includes an IMU and on-board orientation estimate, using the same API format as the X-Series actuator.

Some example uses of the I/O Board:

Reading analog load cells / pressure sensors
Reading signals from limit switches
Reading input from buttons / potentiometers
Reading quadrature encoders
Controlling pneumatic valves (requires external relays)
Controlling solenoids (requires external relays)
Controlling LED lights
Sending digital line signals to other devices

Revisions

Part Number	Description and Downloads	Image
A-2432-01	HEBI I/O Board (rev A) Mechanical Data
A-2116-02	Legacy HEBI I/O Board (rev C) Mechanical Drawing
A-2116-01	Legacy HEBI I/O Board (rev B)

A-2432-01 Interface

The I/O pins described below can be accessed through the HEBI API with I/O Commands / Feedback.

pcba 2075 01 top annotated

The following specifications only apply to A-2432-01 I/O boards. Contact HEBI Robotics for more details about older revisions.

Interface	Rating	Description
Power Input	12V - 48V	This input uses a 2-pin Molex Minifit connector to receive power. It has a reverse voltage protection diode to prevent damage if the connector is miswired. Care should be taken to avoid high voltage transients at this connector.
V I/O Selection Header	3.3V / 5V	This header is used to switch the output voltage between 3.3V and 5V. Do not move this jumper while the device is powered on. This jumper must be populated for the board to function.
Reset Button		This is the hardware reset button for the onboard I/O Micro.

Digital Outputs	0V / V I/O	All digital outputs are buffered with one 8-channel SN74LVC8T245 translation transciever. These outputs are capable of 32mA each in 5V mode or 24mA in 3.3V mode. Do not exceed 100mA total on all digital outputs. Refer to the buffer datasheet for more details.
Digital Inputs	0V / V I/O	Please note that all of the digital inputs are connected directly to the onboard I/O Micro. The I/O Micro runs at 3.3V, but it has 5V tolerant inputs. The inputs are not 5V tolerant when the power is disconnected however, so it is important that external 5V sensors be either powered by this board or incorporate a switching (or level shifting) circuit.
Analog Inputs	0V - 5V	All analog inputs have a range of 0-5V, and have a fixed, first order low pass filter with a cutoff frequency of approximately 4.8kHz. The analog resolution is 12 bits. All of the analog inputs are buffered with TSV324IPT op amps. It is recommended that an external calibration procedure is used for high-accuracy applications.
PWM Outputs	0V - V I/O	By default, the PWM outputs are configured to switch at approximately 20kHz. This frequency is good for DC motor control and basic DAC applications. The PWM timer resolution is 10 bits. All PWM outputs are buffered with one 8-channel SN74LVC8T245 translation transciever. These outputs are capable of 32mA each in 5V mode or 24mA in 3.3V mode. Do not exceed 100mA total on all digital outputs. Refer to the buffer datasheet for more details.
Misc. I/O	0V - V I/O	Additional connections for use with customized firmware. See I/O Micro Pinout for more details.

Additional Specifications

Power & Thermal Considerations

The HEBI I/O Board is rated to a maximum of 300mA from the I/O voltage supplies. Exceeding this current rating may cause the board to malfunction.

The I/O Micro on this board should be heat sunk when this board is assembled into an enclosure. If the electronics are allowed to heat up above 85C the board will stop responding to Ethernet. An onboard temperature sensor can be used to track the temperature of the processor and Ethernet interface.

Data Registers

All data registers updated at a 1kHz interval, so polling the board faster will not produce any benefit.

ESD Precautions

Although there are no overly sensitive components on the I/O Board, there is also no ESD protection. Care must be taken to not damage the device through ESD by taking the appropriate precautions.

General Precautions

The HEBI I/O Board consists of a bare PCB without an enclosure. Care must be taken to protect the connections on the bottom of the PCB. Do not operate the board while it is resting on a conductive surface. Always double check wiring before powering on the board. Never make connections while power is on.

Reference Frame

The reference frame for the I/O board’s IMU (accelerometer, gyro, orientation) is shown in the image below. The origin of the coordinate frame is shown centered on the IMU.

io carrier imu io legacy imu

I/O Utility Board

pcba 2131 01 front pcba 2131 01 back

The HEBI I/O Utility Board is a high-powered version of the traditional I/O Board. This Board allows you to control up to 2 independent LED outputs, 2 independent DC motor outputs, and a high power FET output. A beefy 5V output puts out enough juice to let you run a Raspberry Pi!

It has everything but the kitchen sink!

Features

2 Ethernet Ports for Ethernet Passthrough
Terminal Blocks for All Main Connectors
Same size / bolt pattern as the Standard I/O Board
High power 5V output
2 x LED Drivers
Dual Channel H-Bridge Motor Driver
Bus power output