mirror of
https://github.com/odriverobotics/ODrive.git
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Update getting started guide
Added alligator clip warning Made notes all use same format Tried to improve readability Fixed spelling errors Fixed grammar errors
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100gamma
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@@ -13,6 +13,7 @@ permalink: /
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- [Hardware Requirements](#hardware-requirements)
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- [Wiring up the ODrive](#wiring-up-the-odrive)
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- [Downloading and Installing Tools](#downloading-and-installing-tools)
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- [Firmware](#firmware)
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- [Start `odrivetool`](#start-odrivetool)
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- [Configure M0](#configure-m0)
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- [Position control of M0](#position-control-of-m0)
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@@ -22,7 +23,7 @@ permalink: /
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## Hardware Requirements
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You will need:
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### You will need:
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* One or two [brushless motors](https://docs.google.com/spreadsheets/d/12vzz7XVEK6YNIOqH0jAz51F5VUpc-lJEs3mmkWP1H4Y). It is fine, even recommended, to start testing with just a single motor and encoder.
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* One or two [quadrature incremental encoder(s)](encoders)
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@@ -50,14 +51,18 @@ You will need:
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## Wiring up the ODrive
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<div class="alert">
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Make sure you have a good mechanical connection between the encoder and the motor, slip can cause disasterous oscillations or runaway.
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Make sure you have a good mechanical connection between the encoder and the motor, slip can cause disastrous oscillations or runaway.
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</div>
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All non-power I/O is 3.3V output and 5V tolerant on input, on ODrive v3.3 and newer.
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1. Wire up the motor phases into the 3-phase screw terminals, and the power resistor to the AUX terminal. Wire up the power source to the DC terminal, make sure to pay attention to the polarity. Do not apply power just yet.
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### Wiring up the motors
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* Connect the motor phases into the 3-phase screw terminals. It is not recommended to use a clip-on connector such as an alligator clip, as this can cause issues with the phase resistance/inductance measurements.
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* Connect the power source to the DC terminals. Make sure to pay attention to the polarity.
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* Do not apply power just yet.
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2. Wire up the encoder(s) to J4. The A,B phases are required, and the Z (index pulse) is optional. The A,B and Z lines have 3.3k pull up resistors, for use with open-drain encoder outputs. For single ended push-pull signals with weak drive current (\<4mA), you may want to desolder the pull-ups.
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### Wiring up the encoders
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Connect the encoder(s) to J4. The A,B phases are required, and the Z (index pulse) is optional. The A,B and Z lines have 3.3k pull up resistors, for use with open-drain encoder outputs. For single ended push-pull signals with weak drive current (\<4mA), you may want to desolder the pull-ups.
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@@ -121,20 +126,22 @@ Try step 5 again
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1. [Install Python 3](https://www.python.org/downloads/).
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2. Install the ODrive tools by opening a terminal and typing `pip install odrive` <kbd>Enter</kbd>
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3. __Linux__: set up USB permissions
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3. Set up USB permissions
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```bash
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echo 'SUBSYSTEM=="usb", ATTR{idVendor}=="1209", ATTR{idProduct}=="0d[0-9][0-9]", MODE="0666"' | sudo tee /etc/udev/rules.d/50-odrive.rules
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sudo udevadm control --reload-rules
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sudo udevadm trigger # until you reboot you may need to do this everytime you reset the ODrive
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```
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## Firmware
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#### ODrive v3.5 and later
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Your board should come preflashed with firmware. If you run into problems, follow the instructions [here](odrivetool.md#device-firmware-update) on the DFU procedure before you continue.</div>
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#### ODrive v3.4 and earlier
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Your board does **not** come preflashed with any firmware. Follow the instructions [here](odrivetool.md#device-firmware-update) on the STP Link procedure before you continue.</div>
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## Start `odrivetool`
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<div class="note" markdown="span">__ODrive v3.5 and later:__ Your board should come preflashed with firmware. If you run into problems, follow the instructions [here](odrivetool.md#device-firmware-update) on the DFU procedure before you continue.</div>
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<div class="note" markdown="span">__ODrive v3.4 and earlier:__ Your board does __not__ come preflashed with any firmware. Follow the instructions [here](odrivetool.md#device-firmware-update) on the STP Link procedure before you continue.</div>
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To launch the main interactive ODrive tool, type `odrivetool` <kbd>Enter</kbd>. Connect your ODrive and wait for the tool to find it. Now you can for instance type `odrv0.vbus_voltage` <kbd>Enter</kbd> to inpect the boards main supply voltage.
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To launch the main interactive ODrive tool, type `odrivetool` <kbd>Enter</kbd>. Connect your ODrive and wait for the tool to find it. Now you can, for instance type `odrv0.vbus_voltage` <kbd>Enter</kbd> to inpect the boards main supply voltage.
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It should look something like this:
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```text
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@@ -149,7 +156,7 @@ Out[1]: 11.97055721282959
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The tool you're looking at is a fully capable Python command prompt, so you can type any valid python code.
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You can read more about the odrivetool [here](odrivetool.md).
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You can read more about `odrivetool` [here](odrivetool.md).
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## Configure M0
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@@ -158,46 +165,65 @@ You can read more about the odrivetool [here](odrivetool.md).
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### 1. Set the limits:
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<details><summary markdown="span">Wait, how do I set these?</summary><div markdown="block">
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In the previous step we started `odrivetool`. In there, you can assign variables directly by name.
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For instance, to set the current limit of M0 to 10A you would type: `odrv0.axis0.motor.config.current_lim = 10` <kbd>Enter</kbd>
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</div></details>
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* The current limit: `odrv0.axis0.motor.config.current_lim` [A]. The default current limit, for safety reasons, is set to 10A. This is quite weak, and good for making sure the drive is stable. Once you have tuned the drive, you can increase this to 75A to get some performance. Note that above 75A, you must change the current amplifier gains. You do this by requesting a different current range. i.e. for 90A on M0: 'odrv0.axis0.motor.config.requested_current_range = 90' [A], then save the configeration and reboot as the gains are written out to the DRV (MOSFET driver) only during startup.
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* Note: The motor current and the current drawn from the power supply is not the same in general. You should not look at the power supply current to see what is going on with the motor current.
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<details><summary markdown="span">Ok so tell me how it actually works then...</summary><div markdown="block">
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The current in the motor is only connected to the current in the power supply _sometimes_ and other times it just cycles out of one phase and back in the other. This is what the modulation magnitude is (sometimes people call this duty cycle, but that's a bit confusing because we use SVM not straight PWM). When the modulation magnitude is 0, the average voltage seen across the motor phases is 0, and the motor current is never connected to the power supply. When the magnitude is 100%, it is always connected, and at 50% it's connected half the time, and cycled in just the motor half the time.
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#### Current limit
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`odrv0.axis0.motor.config.current_lim` [A].
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The default current limit, for safety reasons, is set to 10A. This is quite weak, but good for making sure the drive is stable. Once you have tuned the oDrive, you can increase this to 75A to increase performance. Note that above 75A, you must change the current amplifier gains. You do this by requesting a different current range. i.e. for 90A on M0: `odrv0.axis0.motor.config.requested_current_range = 90` [A], then save the configuration and reboot as the gains are written out to the DRV (MOSFET driver) only during startup.
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The largest effect on modulation magnitude is speed. There are other smaller factors, but in general: if the motor is still it's not unreasonable to have 50A in the motor from 5A on the power supply. When the motor is spinning close to top speed, the power supply current and the motor current will be somewhat close to each other.
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*Note: The motor current and the current drawn from the power supply is not the same in general. You should not look at the power supply current to see what is going on with the motor current.*
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<details><summary markdown="span">Ok, so tell me how it actually works then...</summary><div markdown="block">
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The current in the motor is only connected to the current in the power supply _sometimes_ and other times it just cycles out of one phase and back in the other. This is what the modulation magnitude is (sometimes people call this duty cycle, but that's a bit confusing because we use SVM not straight PWM). When the modulation magnitude is 0, the average voltage seen across the motor phases is 0, and the motor current is never connected to the power supply. When the magnitude is 100%, it is always connected, and at 50% it's connected half the time, and cycled in just the motor half the time.
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The largest effect on modulation magnitude is speed. There are other smaller factors, but in general: if the motor is still it's not unreasonable to have 50A in the motor from 5A on the power supply. When the motor is spinning close to top speed, the power supply current and the motor current will be somewhat close to each other.
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</div></details>
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* The velocity limit: `odrv0.axis0.controller.config.vel_limit` [counts/s]. The motor will be limited to this speed; again the default value is quite slow.
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* You can change `odrv0.axis0.motor.config.calibration_current` [A] to the largest value you feel comfortable leaving running through the motor continously when the motor is stationary. If you are using a small motor (i.e. 15A current rated) you may need to reduce `calibration_current` to a value smaller than the default.
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#### Velocity limit
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`odrv0.axis0.controller.config.vel_limit` [counts/s].
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The motor will be limited to this speed. Again the default value is quite slow.
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#### Calibration current
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You can change `odrv0.axis0.motor.config.calibration_current` [A] to the largest value you feel comfortable leaving running through the motor continuously when the motor is stationary. If you are using a small motor (i.e. 15A current rated) you may need to reduce `calibration_current` to a value smaller than the default.
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### 2. Set other hardware parameters:
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### 2. Set other hardware parameters
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* `odrv0.config.brake_resistance` [Ohm]: This is the resistance of the brake resistor. If you are not using it, you may set it to `0`.
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* `odrv0.axis0.motor.config.pole_pairs`: This is the number of **magnet poles** in the rotor, **divided by two**. You can simply count the number of permanent magnets in the rotor, if you can see them. _Note: this is not the same as the number of coils in the stator._
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* `odrv0.axis0.motor.config.motor_type`: This is the type of motor being used. Currently two types of motors are supported: High-current motors (`MOTOR_TYPE_HIGH_CURRENT`) and Gimbal motors (`MOTOR_TYPE_GIMBAL`).
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<details><summary markdown="span">Which `motor_type` to choose?</summary><div markdown="block">
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If you're using a regular hobby brushless motor like [this](https://hobbyking.com/en_us/turnigy-aerodrive-sk3-5065-236kv-brushless-outrunner-motor.html) one, you should set `motor_mode` to `MOTOR_TYPE_HIGH_CURRENT`. For low-current gimbal motors like [this](https://hobbyking.com/en_us/turnigy-hd-5208-brushless-gimbal-motor-bldc.html) one, you should choose `MOTOR_TYPE_GIMBAL`. Do not use `MOTOR_TYPE_GIMBAL` on a motor that is not a gimbal motor, as it may overheat the motor or the ODrive.
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**Further detail:**
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If 100's of mA of current noise is "small" for you, you can choose `MOTOR_TYPE_HIGH_CURRENT`.
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If 100's of mA of current noise is "large" for you, and you do not intend to spin the motor very fast (omega * L << R), and the motor is fairly large resistance (1 ohm or larger), you can chose `MOTOR_TYPE_GIMBAL`.
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If 100's of mA current noise is "large" for you, _and_ you intend to spin the motor fast, then you need to replace the shunt resistors on the ODrive.
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</div></details>
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Note: When using gimbal motors, `current_lim` and `calibration_current` actually mean "voltage limit" and "calibration voltage", since we don't use current feedback. This means that if you set it to 10, it means 10V, despite the name of the parameter.
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* _if using encoder_: `odrv0.axis0.encoder.config.cpr`: Encoder Count Per Revolution (CPR). This is 4x the Pulse Per Revolution (PPR) value. Usually this is indicated in the datasheet of your encoder.
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* _if not using encoder_:
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* If you wish to run in sensorless mode, please see [Setting up Sensorless](commands.md#setting-up-sensorless).
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* If you are using hall sensor feedback, please see the [hoverboard motor example](hoverboard.md).
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`odrv0.config.brake_resistance` [Ohm]
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This is the resistance of the brake resistor. If you are not using it, you may set it to `0`.
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`odrv0.axis0.motor.config.pole_pairs`
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This is the number of **magnet poles** in the rotor, **divided by two**. To find this, you can simply count the number of permanent magnets in the rotor, if you can see them. If you can't see them, try sliding a magnet around the rotor, and counting how many times it stops. This will be the number of **pole pairs**. If you use a magnetic piece of metal instead of a magnet, you will get the number of **magnet poles**.
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### 3. Save configuration.
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You can save all `.config` parameters to persistent memory such that the ODrive remembers them between power cycles.
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_Note: this is not the same as the number of coils in the stator._
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`odrv0.axis0.motor.config.motor_type`
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This is the type of motor being used. Currently two types of motors are supported: High-current motors (`MOTOR_TYPE_HIGH_CURRENT`) and gimbal motors (`MOTOR_TYPE_GIMBAL`).
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<details><summary markdown="span">Which <code>motor_type</code> to choose?</summary><div markdown="block">
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If you're using a regular hobby brushless motor like [this](https://hobbyking.com/en_us/turnigy-aerodrive-sk3-5065-236kv-brushless-outrunner-motor.html) one, you should set `motor_mode` to `MOTOR_TYPE_HIGH_CURRENT`. For low-current gimbal motors like [this](https://hobbyking.com/en_us/turnigy-hd-5208-brushless-gimbal-motor-bldc.html) one, you should choose `MOTOR_TYPE_GIMBAL`. Do not use `MOTOR_TYPE_GIMBAL` on a motor that is not a gimbal motor, as it may overheat the motor or the ODrive.
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**Further detail:**
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If 100's of mA of current noise is "small" for you, you can choose `MOTOR_TYPE_HIGH_CURRENT`.
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If 100's of mA of current noise is "large" for you, and you do not intend to spin the motor very fast (Ω * L << R), and the motor is fairly large resistance (1 ohm or larger), you can chose `MOTOR_TYPE_GIMBAL`.
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If 100's of mA current noise is "large" for you, _and_ you intend to spin the motor fast, then you need to replace the shunt resistors on the ODrive.
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</div></details> <br>
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*Note: When using gimbal motors,* `current_lim` *and* `calibration_current` *actually mean "voltage limit" and "calibration voltage", since we don't use current feedback. This means that if you set it to 10, it means 10V, despite the name of the parameter.*
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#### If using encoder
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`odrv0.axis0.encoder.config.cpr`: Encoder Count Per Revolution [CPR]
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This is 4x the Pulse Per Revolution (PPR) value. Usually this is indicated in the datasheet of your encoder.
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#### If not using encoder
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* If you wish to run in sensorless mode, please see [Setting up sensorless](commands.md#setting-up-sensorless).
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* If you are using hall sensor feedback, please see the [hoverboard motor example](hoverboard.md).
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### 3. Save configuration
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You can save all `.config` parameters to persistent memory so the ODrive remembers them between power cycles.
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* `odrv0.save_configuration()` <kbd>Enter</kbd>.
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Due to a [known issue](https://github.com/madcowswe/ODrive/issues/183) it is strongly recommended that you reboot following every save of your configuration using `odrv0.reboot()`.
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@@ -205,7 +231,7 @@ Due to a [known issue](https://github.com/madcowswe/ODrive/issues/183) it is str
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## Position control of M0
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Let's get motor 0 up and running. The procedure for motor 1 is exactly the same, so feel free to replace read "axis1" wherever it says "axis0".
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Let's get motor 0 up and running. The procedure for motor 1 is exactly the same, so feel free to substitute `axis0` wherever it says `axis0`.
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1. Type `odrv0.axis0.requested_state = AXIS_STATE_FULL_CALIBRATION_SEQUENCE` <kbd>Enter</kbd>. After about 2 seconds should hear a beep. Then the motor will turn slowly in one direction for a few seconds, then back in the other direction.
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@@ -215,12 +241,13 @@ Let's get motor 0 up and running. The procedure for motor 1 is exactly the same,
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The startup procedure is demonstrated [here](https://www.youtube.com/watch?v=VCX1bA2xnuY).
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**Note**: the rotor must be allowed to rotate without any biased load during startup. That means mass and weak friction loads are fine, but gravity or spring loads are not okay. Also note that in the video, the motors spin after initalisation, but in the current software the default behaviour is not like that.
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*Note: the rotor must be allowed to rotate without any biased load during startup. That means mass and weak friction loads are fine, but gravity or spring loads are not okay. Also note that in the video, the motors spin after initialization, but in the current software the default behaviour is not like that.*
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<details><summary markdown="span">Help, something isn't working!</summary><div markdown="block">
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Check the encoder wiring and that the encoder is firmly connected to the motor. Check the value of `hex(odrv0.axis0.error)` and then refer to the [error code documentation](troubleshooting.md#error-codes) for details.
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Once you have understood the error and fixed its cause, you may clear the error state (`odrv0.axis0.error = 0` <kbd>Enter</kbd>) and retry. You may also need to clear the error state of other subcomponents (e.g. `odrv0.axis0.motor.error`).
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Once you understand the error and have fixed its cause, you may clear the error state with (`odrv0.axis0.error = 0` <kbd>Enter</kbd>) and retry. You may also need to clear the error state of other subcomponents (e.g. `odrv0.axis0.motor.error = 0`).
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</div></details>
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2. Type `odrv0.axis0.requested_state = AXIS_STATE_CLOSED_LOOP_CONTROL` <kbd>Enter</kbd>. From now on the ODrive will try to hold the motor's position. If you try to turn it by hand, it will fight you gently. That is unless you bump up `odrv0.axis0.motor.config.current_lim`, in which case it will fight you more fiercely.
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@@ -228,8 +255,14 @@ Let's get motor 0 up and running. The procedure for motor 1 is exactly the same,
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### Other control modes
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The ODrive also supports velocity control and current (torque) control.
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* **Velocity control**: Set `odrv0.axis0.controller.config.control_mode = CTRL_MODE_VELOCITY_CONTROL`. You can now control the velocity with `odrv0.axis0.controller.vel_setpoint = 5000`. Units are counts/s.
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* **Current control**: Set `odrv0.axis0.controller.config.control_mode = CTRL_MODE_CURRENT_CONTROL`. You can now control the current with `odrv0.axis0.controller.vel_setpoint = 3`. Units are A. **NOTE**: There is no velocity limiting in current control mode. Make sure that you don't overrev the motor, or exceed the max speed for your encoder.
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#### Velocity control
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Set `odrv0.axis0.controller.config.control_mode = CTRL_MODE_VELOCITY_CONTROL`.
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You can now control the velocity with `odrv0.axis0.controller.vel_setpoint = 5000` [count/s].
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#### Current control
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Set `odrv0.axis0.controller.config.control_mode = CTRL_MODE_CURRENT_CONTROL`.
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You can now control the current with `odrv0.axis0.controller.vel_setpoint = 3` [A].
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*Note: There is no velocity limiting in current control mode. Make sure that you don't overrev the motor, or exceed the max speed for your encoder.*
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## What's next?
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Reference in New Issue
Block a user