This document presents the steps to setup an environment for using the EVAL-CN0189-SDPZ evaluation board together with the Xilinx KC705 FPGA board, the Xilinx Embedded Development Kit (EDK) and the Micrium µC-Probe run-time monitoring tool. Below is presented a picture of the EVAL-CN0189-SDPZ Evaluation Board with the Xilinx KC705 board.
For component evaluation and performance purposes, as opposed to quick prototyping, the user is directed to use the part evaluation setup. This consists of:
The SDP-B controller board is part of Analog Devices System Demonstration Platform (SDP). It provides a high speed USB 2.0 connection from the PC to the component evaluation board. The PC runs the evaluation software. Each evaluation board, which is an SDP compatible daughter board, includes the necessary installation file required for performance testing.
Note: it is expected that the analog performance on the two platforms may differ.
Below is presented a picture of SDP-B Controller Board with the EVAL-CN0189-SDPZ Evaluation Board.
The CN-0189 circuit incorporates a dual axis ADXL203 accelerometer and the AD7887 12-bit successive approximation (SAR) ADC to create a dual axis tilt measurement system. The ADXL203 is a polysilicon surface micromachined sensor and signal conditioning circuit. Acceleration in the X or Y axis will produce a corresponding output voltage on the XOUT or YOUT output pins of the device. The X axis and Y axis are perpendicular to one another. The AD8608 quad op amp buffers, attenuates, and level shifts the [adi>ADXL203]] outputs so they are at the proper levels to drive the inputs of the AD7887. The rail-to-rail input/output AD8608 is chosen for its low offset voltage (65 μV maximum), low bias current (1 pA maximum), low noise (8 nV/√Hz), and small footprint (14-lead SOIC or TSSOP). The AD7887 is configurable for either dual or single channel operation via the on-chip control register. In this application it is configured for dual channel mode, allowing the user to monitor both outputs of the ADXL203, thereby providing a more accurate and complete solution.
The first objective is to ensure that you have all of the items needed and to install the software tools so that you are ready to create and run the evaluation project.
The following table presents a short description the reference design archive contents.
|Bit||Contains the KC705 configuration file that can be used to program the system for quick evaluation.|
|Microblaze||Contains the EDK 13.4 project for the Microblaze softcore that will be implemented in the KC705 FPGA.|
|Software||Contains the source files of the software project that will be run by the Microblaze processor.|
|uCProbeInterface||Contains the uCProbe interface and the .elf symbols file used by uC-Probe to access data from the Microbalze memory.|
Before connecting the ADI evaluation board to the Xilinx KC705 make sure that the VADJ_FPGA voltage of the KC705 is set to 3.3V. For more details on how to change the setting for VADJ_FPGA visit the Xilinx KC705 product page.
At this point everything is set up and it is possible to start the evaluation of the ADI hardware through the controls in the uC-Probe application provided in the reference design.
Launch uC-Probe from the Start → All Programs → Micrium → uC-Probe.
Select uC-Probe options.
Set target board communication protocol as RS-232
Setup RS-232 communication settings
The following figure presents the uC-Probe interface that can be used for monitoring and controlling the operation of the EVAL-CN0189-SDPZ evaluation board.
The communication with the board is activated / deactivated by toggling the ON/OFF switch. The Activity LED turns green when the communication is active. If the ON/OFF switch is set to ON and the Activity LED is BLACK it means that there is a communication problem with the board. See the Troubleshooting section for indications on how to fix the communication problems.
The MEASUREMENTS section shows the raw data read from the AD7887 as well as the corrected data, the acceleration on the X and Y axis and the rotations on the X and Y axis - asin(x) and acos(y). The data corrections are performed using the offsets and gains shown in the Calibration parameters section. At any time a new calibration can be performed to update the calibration parameters. A new calibration is started by setting the Run calibration switch to ON. This will cause the Calibration status - Running LED and also the LED corresponding to the current calibration step to be lit. A calibration is done by taking 4 data readings in the following conditions:
When the data readings for a calibration step are stable toggle the Move to next step switch to move to the next step. When all the 4 steps have been completed the Calibration status - Complete LED is lit and the new offset and gain values are computed and displayed in the Calibration parameters section. These new values will be used to correct all the subsequent data readings. A calibration can be stopped at any time by setting the Run calibration switch to OFF.
In case there is a communication problem with the board the follwing actions can be perfomed in order to try to fix the issues: