2010 Accelerometer Documentation?

Technical Sensors
1

Does anyone have any information on the accelerometer that we were provided in the KoP this year?

The WPILib user’s guide tells us that it’s I2C based, but that’s all the information I can find. The kit checklist just shows a picture, and there’s no documentation on the FIRST site as there is for the gyro and encoder, not even a part number. I haven’t had a chance to actually look at the board to search for anything that could help.

So, for now, we have no idea how to even hook it up, not even going on to actually reading it and using the data (hopefully WPI’s “shortly after kickoff” will be soon), unless I’ve missed something. Is everyone else in the same situation?

2

It is documented in the 2010 Sensor Manual

http://usfirst.org/uploadedFiles/Community/FRC/Game_and_Season__Info/2010_Assets/2010%20Sensor%20Manual.pdf

3

It would be great if there were a page where you could find this link. Where did you come up with it, Eric?

4

I found it under section 8 of the manual’s jump page: http://usfirst.org/roboticsprograms/frc/content.aspx?id=452

5

I wonder why the data sheet for the Gyro and the AS5030 are not also on that jump page.

6

They’re under the Section 10 subgroup on here: http://usfirst.org/roboticsprograms/frc/content.aspx?id=452

7

Wow, I can’t believe that I didn’t even think to look for that :yikes:

Thanks alot!

8

A question, not about the accelerometer but rather about the gyroscope:

We looked at the pin configuration on the documentation that FIRST sent us, and while the picture of the gyroscope looks exactly like the gyroscope we received, the pin configuration doesn’t match the structure of the gyroscope at all.

For instance:

In the schematic, the Temperature and Voltage outputs are on opposite sides.

On the gyro, there are three Temperature and three Voltage outputs, and they lie next to each other in two rows.

Can someone help us? Is the documentation / gyroscope incorrect? Or are we just missing something?

And as a side note, if you do know, how would we wire the gyroscope using a PWM?

Regards, Team 339 Kilroy (FRC)

9

The pin structure is as follows:


Rate           Temperature
5 Volts        5 Volts
Ground        Ground

Wire your PWM cable such that the white signal line goes to either rate or temperature, the red power line goes to 5 Volts, and the black line goes to ground.

The signals are closest to the signal names: The ground is closest to the edge of the board.

I’ll try to update the doc.

10

Istheir a test VI to test the accelerometer using I2C in the cRIO code this year?? The one I found was only for testing last years unit using analog inputs??

thanks…

anyone have any test code??

11

Thanks for the fast response.

Should have specified - we need to know which way to solder the PWM to the gyro, not the gyro to the digital board. Thanks for the additional information, though.

We have one PWM space for Rate and another for Temperature.

We figure that we won’t need to use temperature, so all we need to know is which way to orient the PWM (white wire out, or black wire out?).

Regards, Team 339 Kilroy (FRC)

12

Emphasis mine. Just read the post a bit more carefully.

13

Depends on your language of choice. I added 2 examples for using the ADXL345 one with I2C and the other with SPI, both for LabVIEW. I haven’t seen any examples for C++ or Java yet. What language are you trying to use?

14

Here’s an interesting App Note if your trying to figure out what to do with your Accelerometer once you get it working.

http://www.analog.com/static/imported-files/application_notes/AN-1023.pdf

Make sure to checkout the I2C threads on chief delphi too. There is some discussion of NI’s implementation of I2c in the FpGa.

Bc

15