Differences between revisions 6 and 7
Revision 6 as of 2010-10-22 22:13:47
Size: 4556
Editor: DavidCary
Comment: Supermodified hobby servo board?
Revision 7 as of 2012-10-12 19:51:18
Size: 4596
Editor: localhost
Comment: converted to 1.6 markup
Deletions are marked like this. Additions are marked like this.
Line 3: Line 3:
http://i324.photobucket.com/albums/k352/kb1gtt/OSV3-OE_2.jpg
http://i324.photobucket.com/albums/k352/kb1gtt/Mag_mount_330x330.jpg
http://www.viveckbansal.com/SVB_4249-Edit.jpg
{{http://i324.photobucket.com/albums/k352/kb1gtt/OSV3-OE_2.jpg}}
{{http://i324.photobucket.com/albums/k352/kb1gtt/Mag_mount_330x330.jpg}}
{{http://www.viveckbansal.com/SVB_4249-Edit.jpg}}
Line 15: Line 15:
  * ["ConstructionTutorial MG995 open-encoder"] -- Open Servo wiki
  * [http://www.openservo.com/forums/viewtopic.php?t=766 "Question about precision and repeatability" -- Open Servo discussion forum] has lots of discussion on encoders in general: linear pots (as on standard unmodified analog hobby servos), various optical sensors, various magnetic sensors and various magnets and magnetic fields, alignment ideas, etc. ''(perhaps someone could summarize this on the wiki?)''
  * [http://www.openservo.com/forums/viewtopic.php?t=821 "FYI: Magnetic encoder ICs" -- Open Servo discussion forum] briefly discusses the encoder used in the first version of the Open encoder. The austria microsystems 5046 does have AN out, the 5045 does not.
  * [http://www.openservo.com/forums/viewtopic.php?t=940 "Open-Encoder-MG995" -- Open Servo discussion forum] has lots of photos of actual parts (prototypes) ''(perhaps someone could summarize this on the wiki?)''
  * [http://www.nedharvey.com/jaredharvey/Files/projects/open-encoder/index.htm FEA Magnetic encoder Analysis by Jared]
  * [http://batchpcb.com/index.php/Products/23010 BatchPCB: empty Open Encoder PCB]
  * [http://vimeo.com/10364526 a little video showing OE working in a servo]
  * the pot or Open Encoder or some other encoder allows a main controller to poll all the servos and figure out their current positions (this is analogous to [http://en.wikipedia.org/wiki/proprioception proprioception]).
  * the open-source [http://reprap.org/wiki/Magnetic_Rotary_Encoder_1.0 RepRap Magnetic Rotary Encoder 1.0] seems surprisingly similar to this Open Servo open encoder.
  * [http://www.austriamicrosystems.com/eng/Products/Magnetic-Encoders/Rotary-Encoders/AS5046 austriamicrosystems: AS5046 Rotary Encoder IC] "The AS5046 is a contactless magnetic angle encoder for accurate measurement up to 360° ... The AS5046 provides a digital serial 12-bit as well as a programmable 10-bit ratiometric analog output that is directly proportional to the angle of a magnet, rotating over the chip. An internal voltage regulator allows operation of the AS5046 from 3.3V or 5.0V supplies."
  * [http://www.austriamicrosystems.com/eng/Products/Magnetic-Encoders/Rotary-Encoders/AS5045 austriamicrosystems: AS5045 Rotary Encoder IC] "The AS5045 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360°. It is a system-on-chip, combining integrated Hall elements, analog front end and digital signal processing in a single device. ... The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 0.0875° = 4,096 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. ... An internal voltage regulator allows the AS5045 to operate at either 3.3V or 5.0V supplies."
  * [http://reprap.org/wiki/MagServo MagServo] is another open-source project that uses magnetic encoder to make a DC motor act more like a stepper motor.
  * [http://letsmakerobots.com/node/18470 Let's make robots: "Hack your servo v2.00"] has detailed instructions for installing an Austrian Microsystems AS5040 magnetic encoder (10-bit resolution) inside a hobby servo such as the Hitec HS485 HB.
  * [http://letsmakerobots.com/node/18615 Let's make robots: "Hack your servo v3.00 - Get full PID position and speed control from your hobby servo"] had detailed instructions for installing an Austrian Microsystems AS5145 magnetic encoder (12-bit resolution) plus an ATMega 328P and a Freescale MC33887 motor driver (5 amp) inside a hobby servo such as the Hitec HS485 HB. The result can apparently can be configured for I2C, RS232 or RS485. Is this the same as the [http://www.01mech.com/supermodified "Supermodified hobby servo board"]?
  * [[ConstructionTutorial_MG995_open-encoder]] -- Open Servo wiki
  * [[http://www.openservo.com/forums/viewtopic.php?t=766|"Question about precision and repeatability" -- Open Servo discussion forum]] has lots of discussion on encoders in general: linear pots (as on standard unmodified analog hobby servos), various optical sensors, various magnetic sensors and various magnets and magnetic fields, alignment ideas, etc. ''(perhaps someone could summarize this on the wiki?)''
  * [[http://www.openservo.com/forums/viewtopic.php?t=821|"FYI: Magnetic encoder ICs" -- Open Servo discussion forum]] briefly discusses the encoder used in the first version of the Open encoder. The austria microsystems 5046 does have AN out, the 5045 does not.
  * [[http://www.openservo.com/forums/viewtopic.php?t=940|"Open-Encoder-MG995" -- Open Servo discussion forum]] has lots of photos of actual parts (prototypes) ''(perhaps someone could summarize this on the wiki?)''
  * [[http://www.nedharvey.com/jaredharvey/Files/projects/open-encoder/index.htm|FEA Magnetic encoder Analysis by Jared]]
  * [[http://batchpcb.com/index.php/Products/23010|BatchPCB: empty Open Encoder PCB]]
  * [[http://vimeo.com/10364526|a little video showing OE working in a servo]]
  * the pot or Open Encoder or some other encoder allows a main controller to poll all the servos and figure out their current positions (this is analogous to [[http://en.wikipedia.org/wiki/proprioception|proprioception]]).
  * the open-source [[http://reprap.org/wiki/Magnetic_Rotary_Encoder_1.0|RepRap Magnetic Rotary Encoder 1.0]] seems surprisingly similar to this Open Servo open encoder.
  * [[http://www.austriamicrosystems.com/eng/Products/Magnetic-Encoders/Rotary-Encoders/AS5046|austriamicrosystems: AS5046 Rotary Encoder IC]] "The AS5046 is a contactless magnetic angle encoder for accurate measurement up to 360° ... The AS5046 provides a digital serial 12-bit as well as a programmable 10-bit ratiometric analog output that is directly proportional to the angle of a magnet, rotating over the chip. An internal voltage regulator allows operation of the AS5046 from 3.3V or 5.0V supplies."
  * [[http://www.austriamicrosystems.com/eng/Products/Magnetic-Encoders/Rotary-Encoders/AS5045|austriamicrosystems: AS5045 Rotary Encoder IC]] "The AS5045 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360°. It is a system-on-chip, combining integrated Hall elements, analog front end and digital signal processing in a single device. ... The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 0.0875° = 4,096 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. ... An internal voltage regulator allows the AS5045 to operate at either 3.3V or 5.0V supplies."
  * [[http://reprap.org/wiki/MagServo|MagServo]] is another open-source project that uses magnetic encoder to make a DC motor act more like a stepper motor.
  * [[http://letsmakerobots.com/node/18470|Let's make robots: "Hack your servo v2.00"]] has detailed instructions for installing an Austrian Microsystems AS5040 magnetic encoder (10-bit resolution) inside a hobby servo such as the Hitec HS485 HB.
  * [[http://letsmakerobots.com/node/18615|Let's make robots: "Hack your servo v3.00 - Get full PID position and speed control from your hobby servo"]] had detailed instructions for installing an Austrian Microsystems AS5145 magnetic encoder (12-bit resolution) plus an ATMega 328P and a Freescale MC33887 motor driver (5 amp) inside a hobby servo such as the Hitec HS485 HB. The result can apparently can be configured for I2C, RS232 or RS485. Is this the same as the [[http://www.01mech.com/supermodified|"Supermodified hobby servo board"]]?

Open Encoder (OE) is a digital I2C full rotation position feed back device.

http://i324.photobucket.com/albums/k352/kb1gtt/OSV3-OE_2.jpg http://i324.photobucket.com/albums/k352/kb1gtt/Mag_mount_330x330.jpg http://www.viveckbansal.com/SVB_4249-Edit.jpg

The OpenServoV3 can use back EMF sensing to estimate the speed of the servo, and the pot that came with the servo to measure its position. The Open Encoder replaces that pot with a different kind of encoder, which has:

  • higher resolution than the pot
  • works properly with continuous-rotation servos (most pots have a "dead zone" at one angle of continuous rotation)

What chip does the Open Encoder use? Can this PCB can accept either the AS5046 or the AS5045 ?

Related links:

OpenEncoder (last edited 2012-10-12 19:51:18 by localhost)