robovero sensors
download
The patch, patched firmware, and compiled firmware for the Robovero can be downloaded below. For
instructions on building and installing the firmware, visit the robovero
website: http://www.robovero.org.
A simple C program can also be downloaded below. This program will connect to the robovero and
read from the sensors using POSIX compliant C code. The top of the source file contains
compilation and execution instructions.
| Description | Version | Last change | Download |
|---|---|---|---|
| Binaries | v1.2 | March 24, 2012 | Tarball / Zip |
| Source code | v1.2 | March 24, 2012 | Tarball / Zip |
| Patch | v1.2 | March 24, 2012 | Patch / GitHub |
| Simple C Example | v1.0 | December 8, 2012 | Source / GitHub |
media
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manual
1. Overview
The sensors firmware patch allows for easy configuration and reading from the accelerometer, magnometer, and gyroscope on the Robovero. Without this patch, it's not possible to query the state of these sensors at a high frequency. The modification closely follows existing firmware philosophy, and provides six new command line functions which can be invoked. All integer arguments must be specified in hexadecimal format.
2. Commands
2.1. Accelerometer
Configuring the accelerometer can be done with the command below.
configAccel power x_on y_on z_on output_hz scaleThe table below contains a description of each argument.
| Argument | Description |
|---|---|
| power | Enables or disables the sensor. Set to 1 to enable it or 0 to disable it. |
| x_on | Enables or disables the x axis. Set to 1 to enable it or 0 to disable it. |
| y_on | Enables or disables the y axis. Set to 1 to enable it or 0 to disable it. |
| z_on | Enables or disables the z axis. Set to 1 to enable it or 0 to disable it. |
| output_hz | Specify the frequency at which the sensor should update, in Hz. Possible values are: 50, 100, 400, or 1000. |
| scale | Specify the scale, in units g, at which the sensor should operate. Possible values are: 2, 4, or 8. |
The current state of the accelerometer can be retrieved with the command below.
readAccel
Upon execution, readAccel will output the current sensor value for each enabled axis in
hexadecimal format. The output order will be x y z. If an axis isn't enabled, the output
will be skipped. Each value output is followed by a new line character. Additionally, the output
values are offset by 32768.
To convert the output value to g, the equation below can be used.
g = ( value - 32768 ) / ( 32768 / scale )2.2. Magnometer
Configuring the magnometer can be done with the command below.
configMag power bias output_cHz field_rangeThe table below contains a description of each argument.
| Argument | Description |
|---|---|
| power | Enables or disables the sensor. Set to 1 to enable it or 0 to disable it. |
| bias | Set the bias configuration. Set to 0 for normal bias, 1 for positive bias, or 2 for negative bias. |
| output_cHz | Specify the frequency at which the sensor should update, in centi-Hz. Possible values are: 75, 150, 300, 750, 1500, 3000, or 7500. |
| field_range | Specify the field range, in units deci-Gauss, at which the sensor should operate. Possible values are: 13, 19, 25, 40, 47, 56, or 81. |
The current state of the magnometer can be retrieved with the command below.
readMag
Upon execution, readMag will output the current sensor value for each enabled axis in
hexadecimal format. The output order will be x y z. Each value output is followed by a
new line character. Additionally, the output values are offset by 4096. A value of 0 corresponds
to NaN.
To convert the output value to G, the equation below can be used.
G = ( value - 4096 ) / ( 4096 / ( field_range / 10 ) )2.3. Gyroscope
Configuring the gyroscope can be done with the command below.
configGyro power x_on y_on z_on output_hz scaleThe table below contains a description of each argument.
| Argument | Description |
|---|---|
| power | Enables or disables the sensor. Set to 1 to enable it or 0 to disable it. |
| x_on | Enables or disables the x axis. Set to 1 to enable it or 0 to disable it. |
| y_on | Enables or disables the y axis. Set to 1 to enable it or 0 to disable it. |
| z_on | Enables or disables the z axis. Set to 1 to enable it or 0 to disable it. |
| output_hz | Specify the frequency at which the sensor should update, in Hz. Possible values are: 100, 200, 400, or 800. |
| scale | Specify the scale, in units dps, at which the sensor should operate. Possible values are: 250, 500, or 2000. |
The current state of the gyroscope can be retrieved with the command below.
readGyro
Upon execution, readGyro will output the current sensor value for each enabled axis in
hexadecimal format. The output order will be x y z. If an axis isn't enabled, the output
will be skipped. Each value output is followed by a new line character. Additionally, the output
values are offset by 32768.
To convert the output value to dps, the equation
below can be used.
dps = ( value - 32768 ) / ( 32768 / scale )3. Firmware Usage
Building and flashing the firmware requires the robovero cross-compilation tools. Instructions on setting up an environment, building, and flashing the firmware can be found at the official Robovero website: http://www.robovero.org.
4. Licensing
The Robovero sensors patch is licensed under the simplified BSD license:
Copyright 2012, Andrew Gottemoller
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted
provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions
and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation and/or other materials provided
with the distribution.
Neither the name of Andrew Gottemoller nor the names of its contributors may be used to endorse
or promote products derived from this software without specific prior written permission.
5. Alternative Licensing
A special license for the Rovoero sensors patch is available if you are unable to meet the conditions of the license described above. For more information, please contact me.