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| resources:eval:user-guides:circuits-from-the-lab:cn0368 [17 Mar 2015 15:59] – created Neil Wilson | resources:eval:user-guides:circuits-from-the-lab:cn0368 [29 Jul 2021 07:52] (current) – Hardware Registration Harvey John De Chavez |
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| ====== Magneto-Resistive Angle and Linear Position Measurements (CN0368) ====== | ====== Magneto-Resistive Rotational Position Measurement (CN0368) ====== |
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| ===== Overview ===== | ===== Overview ===== |
| The circuit is ideal for applications where high speed, accurate, non-contact angle and length measurements are critical such as brushless DC motor control. | The circuit is ideal for applications where high speed, accurate, non-contact angle and length measurements are critical such as brushless DC motor control. |
| |
| | {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:cn0368.jpg?600 |}} |
| ===== General Setup ===== | ===== General Setup ===== |
| *One [[http://www.analog.com/CN0368|EVAL-CN0368-SDPZ]] Evaluation Board | *One [[adi>CN0368|EVAL-CN0368-SDPZ]] Evaluation Board |
| *[[http://www.analog.com/EVAL-SDP-CB1Z|EVAL-SDP-CB1Z]] Evaluation board | *[[adi>EVAL-SDP-CB1Z|EVAL-SDP-CB1Z]] Evaluation board |
| *[[ftp://ftp.analog.com/pub/cftl/CN0368|CN0368 Evaluation Software]] | *[[ftp://ftp.analog.com/pub/cftl/CN0368|CN0368 Evaluation Software]] |
| *One USB Type-A plug to USB Mini-B plug cable. | *One USB Type-A plug to USB Mini-B plug cable. |
| *One diametrically magnetized Neodymium magnet or one Neodymium magnet, approximately two inches in length, magnetized along the length of the magnet. | |
| *One of the following: | *One of the following: |
| *6V DC wallwart. (EVAL-CFTL-6V-PWRZ) | *6V DC wallwart. (EVAL-CFTL-6V-PWRZ) |
| *DC power supply with a 0-6V output. (HP6236B) | *DC power supply with a 0-6V output. (HP6236B) |
| | *One diametrically magnetized Neodymium magnet |
| | *One Neodymium magnet approximately two inches in length, magnetized along the length of the magnet. |
| | |
| ===== Minimum PC/System Requirements ===== | ===== Minimum PC/System Requirements ===== |
| |
| ===== How to Install the Evaluation Software ===== | ===== How to Install the Evaluation Software ===== |
| - Extract the files within the file **CN0368 SDP Eval Software.zip** and open the file **setup.exe**. It is recommended that you install the CN0368 SDP Evaluation Software to the default directory path **C:\Program Files\Analog Devices\CN0368\** and all National Instruments products to **C:\Program Files\National Instruments\**{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_install_2.png?600 |}} | - Extract the files within the file **CN0368 SDP Eval Software.zip** and open the file **setup.exe**. It is recommended that you install the CN0368 SDP Evaluation Software to the default directory path **C:\Program Files\Analog Devices\CN0368\** and all National Instruments products to **C:\Program Files\National Instruments\**{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_2.png?600 |}} |
| - Press **“Next”**.{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_install_3.png?600 |}} | - Press **“Next”**.{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_3.png?600 |}} |
| - Press **“Next”**.{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_install_5.png?600 |}} | - Press **“Next”**.{{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_5.png?600 |}} |
| - Press **“Next”**. | - Press **“Next”**. |
| - Upon completion of the installation of the **CN0368 SDP Eval Software**, the installer for the **ADI SDP Drivers** will execute. Follow the on-screen prompts to install the drivers. It is recommended that you close all other applications before clicking “Next”. This will make it possible to update relevant system files without having to reboot your computer. | - Upon completion of the installation of the **CN0368 SDP Eval Software**, the installer for the **ADI SDP Drivers** will execute. Follow the on-screen prompts to install the drivers. It is recommended that you close all other applications before clicking “Next”. This will make it possible to update relevant system files without having to reboot your computer. |
| - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_install_6.png?600 |}} | - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_6.png?600 |}} |
| - Press **“Next”**. | - Press **“Next”**. |
| - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_install_7.png?600 |}} | |
| - It is recommended that you install the drivers to the default directory path **C:\Program Files\Analog Devices\SDP\Drivers\** | - It is recommended that you install the drivers to the default directory path **C:\Program Files\Analog Devices\SDP\Drivers\** |
| - Press **“Install”** to install the Drivers and complete the installation of all software necessary to evaluate the **EVAL-CN0368-SDPZ** | - Press **“Install”** to install the Drivers and complete the installation of all software necessary to evaluate the **EVAL-CN0368-SDPZ** |
| ===== Opening and Enabling the Evaluation Software ===== | ===== Opening and Enabling the Evaluation Software ===== |
| - Launch the executable found at **C:\Program Files\Analog Devices\CN0368** and press the **“Connect"** button. | - Launch the executable found at **C:\Program Files\Analog Devices\CN0368** and press the **“Connect"** button. |
| - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_front_panel_2.png?600 |}} | - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_8.png?600 |}} |
| ===== Step by Step Instruction for Calibrating the System ===== | ===== Calibration Methods ===== |
| - The following is a step by step guide for manual or automatic calibration of the calibrating the EVAL-CN0368-SDPZ. | ==== Single Temperature Calibration ==== |
| - A manual calibration requires the user to input the maximum and minimum ADC code for each channel of the ADC. | The Single Temperature Calibration method allows the user to calculate VSIN_Offset and VCOS_Offset before calculating the magnetic field angle. This eliminates any error sources associated with a dynamic calibration procedure, but requires extra steps and time. |
| - An automatic calibration allows the software to identify the maximum and minimum ADC code for each channel of the ADC. This method is easier to use than the manual method, however, it may introduce errors if the magnet is spinning with an un-smooth or non-periodic nature. | - Select '**//Single Temperature Calibration//**' from the drop down menu. |
| - {{ :resources:eval:user-guides:circuits-from-the-lab:cn0368:software_front_panel_1.png?600 |}} | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:single_temperature_calibration.png?600|}} |
| - Step 1: Begin by selecting manual or automatic calibration. | - A prompt will appear instructing the user to rotate the magnetic stimulus through 360 degrees. |
| - Step 2: Press the 'Click to Sample' button to begin data conversion. | - In this time the software is actively calculating VSIN_Offset and VCOS_Offset. |
| - Step 3: Rotate the magnet and observe the changing ADC codes. | - Press '**//End Calibration//**' when finished. |
| - Step 4: If manual calibration was selected, you must input the maximum and minimum codes (seen in step 3) in the boxes provided. If automatic calibration was selected, you must simply spin the magnet through several complete revolutions to allow the software to identify the necessary codes. | - The software will display the magnetic field angle, VSIN_Offset, and VCOS_Offset. |
| - The calibration coefficients can be modified to produce a better end result. For example, if one of the maximum ADC codes is mis-represented on the high side, the output angle will never reach +90 degrees or -90 degrees depending on the channel. | - Press '**//Sample Data//**' to actively calculate the magnetic field angle using the offsets calculated during the Single Temperature Calibration. |
| - Once the calibration is complete, proceed to the second tab 'Final Angle(Needle)' to observe the angle information. | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:sample_data.png?600|}} |
| | - Press '**//Click to Stop//**' when finished. |
| | ==== Multiple Temperature Calibration ==== |
| | The Multiple Temperature Calibration procedure is a method of compensating for temperature effects experienced by the amplifier and ADC. The temperature coefficients and offsets are calculated to provide a more accurate magnetic field angle and system response. |
| | - Select //**Multiple Temperature Calibration**// from the drop down menu. |
| | - Place the hardware in a temperature controlled environment at the desired T1. |
| | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:multiple_temperature_calibration_1.png?600|}} |
| | - Press //**Ok**//. |
| | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:multiple_temperature_calibration_2.png?600|}} |
| | - Rotate the stimulus through 360 degrees while VSIN_Offset_T1 and VCOS_Offset_T1 are calculated. |
| | - Press //**Ok**//. |
| | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:multiple_temperature_calibration_3.png?600|}} |
| | - Place the hardware in a temperature controlled environment at the desired T2. |
| | - Press //**Ok**//. |
| | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:multiple_temperature_calibration_4.png?600|}} |
| | - Rotate the stimulus through 360 degrees while VSIN_Offset_T2 and VCOS_Offset_T2 are calculated. |
| | - Press //**Ok**//. |
| | - Press //**Sample Data**// to observe the magnetic field angle results corrected for temperature and offset effects. |
| | ==== Dynamic Calibration ==== |
| | The Dynamic Calibration method actively calculates VSIN_Offset and VCOS_Offset as the magnetic stimulus rotates through 360 degrees. The software then subtracts these offsets in real time. This method is simpler than the Single Temperature Calibration and Multiple Temperature Calibration and can be implemented faster, with more ease. |
| | - Select '**//Dynamic Calibration//**' from the drop down menu. |
| | - {{:resources:eval:user-guides:circuits-from-the-lab:cn0368:dynamic_calibration_2.png?600|}} |
| | - The software will automatically begin to sample and convert the VSIN and VCOS channels of the ADA4571. |
| | - Rotate the magnetic stimulus through 360 degrees. |
| | - The software will display the magnetic field angle, VSIN_Offset, and VCOS_Offset as the stimulus is rotated. |
| | - Early calculations for the magnetic field angle will have large errors until the offset's are calculated more precisely, the accuracy of the system will quickly improve with as few as one or two rotations are required. |
| | - Press '**//Click to Stop//**' when finished. |
| | - The software will revert to its starting position allowing you to experiment with a new calibration method, or simply to sample data with the existing calibration data. |
| |
| | =====Registration===== |
| | <WRAP round tip 80% > |
| | Receive software update notifications, documentation updates, view the latest videos, and more when you register your hardware. [[reg>EVAL-CN0368-SDPZ?&v=RevA|Register]] to receive all these great benefits and more! |
| | </WRAP> |
