Question 1

ADIS16448 Code Examples

Accepted Answer

Q: 
 Do you have any starter code for working with the ADIS16448 ? 
 A: 
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 Yes, we do. The ADIS16448 operates as a "SPI slave," which many embedded processors support with a dedicated interface, configuration registers and communication registers. Managing the actual communication is fairly simple, from a firmware point of view. The attached file contains a project file, for the VDSP ADSP-21469 processor. It provides the register map, runs the SPI at 1 MHz, incorporates minimum delays for SPI traffic, reads the PROD_ID register, sets the decimation filter to reduce the output data rate by a factor of 4, and gathers 4000 samples (20 seconds at ¼ sample rate) which can be plotted using the VDSP workspace.vdw file. 
 This project file includes the following features: 
 
 header file for register address definition 
 code for SPI port configuration 
 code for single-register reads and writes 
 interrupt service routine that reads inertial data after every DIO1 pulse. 
 
 We hope that this code is useful for you. Please note that this code has only been tested on a limited number of systems. While this code functioned correctly at the time of posting, this post does not automatically track updates for the DSP programming tools. Anyone using this code must take responsibility for verifying functionality and reliable operation in their system. 
 Best regards, 
 NevadaMark

Attachments:

ez.analog.com/.../ADSP21469_5F00_ADIS16448_5F00_Project.zip

Question 2

ADIS16448 Connector-Down Design

Accepted Answer

Q: 
 Outside of the example in the datasheet, do you have any other ideas or information that illustrate the ADIS16445 and ADIS16448 in connector-down configurations? 
 -------------------------------------------------------------------------------------------------------------------------------- 
 A: 
 Yes, please see the attached drawings. It contains conceptual and detailed design information on two different configurations.

Attachments:

ez.analog.com/.../ADIS16448_2D00_ConnectorDownTips.PDF

Question 3

ADIS16448 Input Clock on EVAL-ADIS

Accepted Answer

Q: 
 How do I use an input clock to drive sampling in the ADIS16448 , when I am using the EVAL-ADIS to evaluate it? 
 A: 
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 This requires the use of (1) ADIS16448/PCBZ , (1) EVAL-ADIS , a function generator, interface cable and a PC, which has the IMU Evaluation software (v1.8.0 or later) installed. 
 Use the following steps to configure the ADIS16448 and IMU Evaluation software to run off of an input clock source. 
 
 Use the ADIS1644x Wiki Guide to install the ADIS16448/PCBZ on the EVAL-ADIS . and to install the IMU Evaluation software on a PC. LINK: https://wiki.analog.com/resources/eval/user-guides/inertial-mems/imu/adis16448 
 Hook the function generator output up to the DIO4 test point ( EVAL-ADIS ) and the ground pin on J3, as shown below. 
 Set the function generator for a pulse waveform, using the following settings: frequency = 1000Hz, pulse width = 50us, magnitude = 3.3V and offset = 0V. NOTE: The goal is to apply a positive, "0V to +3.3V pulse." Function generators often assume a 50-ohm load when reporting magnitude. For our setup, we actually set the magnitude for 1.65V, which produces 3.3V into a high-impedance load (DIO4). If you aren't sure about this, measure the signal before applying it to the input. +6.6V could damage the unit or evaluation system. 
 Hook the USB to the PC, launch the IMU Evaluation software package and verify basic function in the ADIS16448 . 
 Go into the Register Access menu and change the SMPL_PRD setting to 0. 
 While making sure that the clock signal is disabled, go back to the Main Screen and test the response again. You should see that there is no sensor response, with the clock still off. 
 Enable the clock and test it again. As we can see from the response on the far right, the external clock has enabled sampling and a response in the Main Window . 
 
 Use the following steps to configure and use the Data Capture function with an external clock. Note that the images reflect the software design at v1.8.1, so more recent window designs may differ in appearance, but will support the functions that the following steps illustrate: 
 
 Click on Data Capture at the top of the Main Window . When the Data Capture window appears, click on Advanced Options . 
 The Advanced Options menu provides an opportunity to enable the use of the external trigger. Click on this box and then enter the external clock frequency. This entry enables the data capture time computation in the Data Capture menu. 
 Click on OK to return to the Data Capture menu and enter the storage location and file name for the data file. 
 If you use the Browse function, click on Save to set the location and file name. 
 Select the registers for the data capture by checking on their boxes, set the Record Length (total number of data points) and then click on Start . 
 
 I hope that this helps. Keep your comments coming. We sincerely appreciate your interest in our high-performance MEMS IMUs and eagerly look forward to your feedback. 
 Very best regards, 
 NevadaMark

Question 4

ADIS16448 Accuracy over Temperature

Accepted Answer

Q: 
 Do you have any plots for the ADIS16448's behavior over temperature? 
 ----------------------------------------------------------------------------------------------------- 
 A: 
 Yes, the following plots were part of an early characterization project. Hope this helps. 
 
 Black dotted lines represent 3 sigma of distribution 
 
 Accelerometer Bias vs Temperature 
 
 Accelerometer Sensitivity vs Temperature 
 
 Gyroscope Bias vs Temperature 
 
 Gyroscope Sensitivity vs Temperature

Question 5

ADIS16448 Flex Connector Supplier

Accepted Answer

Q: 
 Where can I purchase the flex connector for connecting the ADIS16448AMLZ to the EVAL-ADISZ ? 
 A: 
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 The short answer is that there is no small-quantity source for these flexible connectors. Flexible circuit connector design, production and purchasing is very similar to printed circuit boards, where suppliers only stock custom-products for those who can forecast and commit to a specific consumption rate. In order to help with short-term needs for this of connector, we partnered with a flex circuit provider (Samtec) to design and produce these flex connectors for use with the product breakout boards: ADIS16334/PCBZ , ADIS16445/PCBZ and ADIS16448/PCBZ . Samtec has give us permission to supply the design files and within these files, they have also provided recommendations for two suggested vendors. For those who plan to use this type of connector in their production designs, please feel free to use these design files to assist your design of a flexible circuit that meets your needs. Click here to access a previous discussion that contains these design files . 
 For those who have already made purchases of a unit ( ADIS16448AMLZ , for example) and the EVAL-ADISZ , only to realize that they should have ordered the breakout board, send me a private message with your email and phone number. While we cannot assure supply or short lead times, we will do our best to arrange for a separate purchase of this cable. Again, the least expensive and quickest access will be through the breakout boards, but we will do our best to help. 
 Note that the ADIS16334 , ADIS16445 and ADIS16448 all share a common electrical interface, so this information applies to all three products. 
 I hope that this helps! 
 Best regards, 
 NevadaMark 
 This FAQ was generated from the following discussion, but has been edited for current relevance: ADIS16448 Flex

Question 6

ADIS16448 Evaluation Tool Overview

Accepted Answer

Q: 
 Where do I find information on evaluation tools for the ADIS16448 Inertial Measurement Unit (IMU)? 
 --------------------------------------------------------------------------------------------------------------------------------------------- 
 A: 
 We offer two different tools that support early evaluation of the ADIS16448. 
 First , for those who want to connect to their own embedded processor system, the ADIS16448/PCBZ is breakout board which simplifies this process. For more information, please visit its product page at: 
 ADIS16448/PCBZ | Analog Devices 
 Also, check out page 22 of the ADIS16448 datasheet (Rev D) to access documentation for the ADIS16448/PCBZ 
 http://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16448.pdf#Page=22 
 
 Note, in future revisions, this information may be on different pages of the datasheet 
 
 Second , for those who want a PC-based evaluation solution, use the ADIS16448/PCB and EVAL-ADIS. The EVAL-ADIS provides a simple method for PC-based communication and data collection from the ADIS16448. For more information on this tool, please visit its product page at www.analog.com/EVAL-ADIS and the following Wiki Guide link for setup and use guidelines: 
 ADIS1644X EVALUATION ON THE EVAL-ADIS [Analog Devices Wiki] 
 These evaluation boards are available for order online at the following link or through our sales channel. 
 http://www.analog.com/en/products/sensors/isensor-mems-inertial-measurement-units/adis16448.html#product-samplebuy 
 For a list of authorized distributors by region, please click on the following link: 
 Sales and Distribution | Analog Devices

Question 7

ADIS16448 Center of Gravity

Accepted Answer

Q: What is the Center of Gravity for the ADIS16448? 
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 A: 
 Based on a simple measurement, I came up with the following estimate:

Question 8

ADIS16448 CRC-16 Code

Accepted Answer

Q: 
 Do you you have any code examples for calculating the new CRC-16 option in the ADIS16448? 
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 A: 
 Yes, please see the attached file.

Attachments:

ADIS16448CRC.rtf

Question 9

ADIS16448 CRC In The Burst Mode!

Accepted Answer

Q: 
 Does the ADIS16448 have any option for CRC coding to help assure proper communication? 
 A: 
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 It does now! Recently, the ADIS16448AMLZ was obsoleted and a new model, ADIS16448BMLZ was introduced to the market. The ADIS16448BMLZ in the same package, has the same pinout, same SPI protocol and the same register map as the ADIS16448AMLZ, but also has an improved calibration (expansion of temperature range) and also has a User-selectable option for adding a CRC-16 code to the end of each Burst Read sequence. This option has not made it into the product datasheet yet, but we wanted to post this information in parallel with the datasheet update process. 
 To enable this feature, set MSC_CTRL[4] = 1. Note, the factory default for this feature will be to disable it. 
 
 Once this is enabled, the Burst Mode read will operate in this manner: 
 
 The ADIS16448 computes the CRC-16 code using the following flow chart: 
 
 Stay tuned for ADIS16448 datasheet updates and more information......

Question 10

ADIS16448 Data Ready Signal During Start-up

Accepted Answer

Q: 
 What does the ADIS16448's data-ready signal do during start-up? 
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 A: 
 Please see the attached file for details on data-ready activity during the ADIS16448's self-initialization process. Note that all the ADIS1630x, ADIS16334, ADIS1636x, ADIS1640x and ADIS16445 will have similar behaviors, albeit with some changes in absolute timing. I hope that this helps!

Question 11

ADIS16448 Start-up Current Demand

Accepted Answer

Q: 
 Does the ADIS16448 have similar start-up transients as the ADIS16488A? 
 ----------------------------------------------------------------------------------------------------------- 
 A: 
 The start-up transients are not as severe on the ADIS16448. Please see the attached file for some observations that we made in our lab. We hope that this helps! Please note that the behaviors in the ADIS1630x, ADIS16334, ADIS1636x, ADIS1640x and ADIS16445 will be similar (with minor differences in the time and peak currents).

Attachments:

ADIS16448_StartUpCurrentDemand.pdf

Question 12

ADIS16448: Magnetometer corrections for acceleration, deceleration and turning errors

Accepted Answer

Q 
 Is the magnetometer (compass) heading corrected for acceleration, deceleration and turning errors or must we implement a manual gyrocompassing algorithm? If so, do you provide such an algorithm? 
 
 A 
 No for these type of corrections, customers need to develop their own algorithms, so they can design and tune them for their unique requirements.

Question 13

ADIS16448 without packaging

Accepted Answer

Q 
 We are seeking a sensor similar to the ADIS16448, but without the pressure sensor and housing, to allow for higher integration. The module must be still functional after an acceleration of approximately 30000g. The technical data should be at least as good as the ADIS16448 
 
 A 
 As far as I am aware, the actual packaging/housing of our ADIS parts contributes to the overall performance of the parts. If it were to be removed, the specifications stated in the datasheet would not apply. In terms of shock survival, the ADIS16448 is rated up to 2000g. There are 6 degree of freedom parts with similar specifications: ADIS16485 ADIS16445

Question 14

ADIS16448 Data Sampling

Accepted Answer

Q: 
 Can you offer more information on the sampling of sensor data in the ADIS16448? 
 A: 
 The gyroscopes, accelerometers, and temperature sensors are all sampled through a common ADC channel, which uses the following sequence to collect data samples. This particular diagram illustrates the sampling sequence for one main data cycle . This diagram represents the case when the ADIS16448 is using its internal clock to control the sample rate. When using an external clock, the sequencing remains the same, but the data cycle period is compressed from 1.22ms to 0.1ms. 
 Within a single cycle, the internal processor collects four samples of each gyroscope (x, y, z) and two samples of each accelerometer (x, y, z). The data "output" from this process represents the average of these multiple samples. The area with pink highlights represents the "average" sample time for each of these sensors. 
 The magnetometer data (x, y, z) comes from a separate ADC channel. The internal processor collects data from these sensors at 1/16th of the rate of the main data loop. This sampling process takes place right after the completion of accelerometer sampling (after second Z-ACCL cycle, which #16 in the figure above this text). 
 I hope that this helps and look forward to your comments, recognition and ideas for improving this content.

Question 15

ADIS16448/PCB Flex Connector Pin Numbers

Accepted Answer

Unfortunately, the pin numbers on the silk screen are not correct. While we explore opportunities to correct this issue, here are two pictures, which clearly identify the errors and the correct pin assignments 
 
 Here are the correct pin assignments:

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