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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Erik Janssen on December 10, 2009, 08:11:47 AM
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This logger uses a micro SD card to read parameters and log details. It automatically creates a new folder with the values as soon as the power is connected.
We found out that motor rpm disturbs the readout of the sensor values and designed a software that takes an average value. This works.
In our setup we use the following parts:
Parts from: www.sparkfun.com
Logomatic V2 micro SD card logger. Power parallel to ESC. XYZ to port 123, UI on port 7-8. Next to port 7 and 8 there is a ground connection; this allows you to solder a servo lead connector directly to the logger.
AttoPilot sensor board for measuring voltage and current. This allows you to calculate power and consumption. This board is soldered directly to the ESC input wires. The leads are put through the PCB directly into the male and female 4mm connector.
www.pololu.com
MMA7260QT XYZ-axis accelerometer, glued with double sided tape to the back of the logger.
The pdf gives all the details of the software modification made.
The picture shows my sensor timer, the logger with the sensor taped to the back and the attopilot shunt in the feed line of the speedcontroller.
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Erik,
I am very impressed! Good work, and I will certainly be asking you for help with my new logomatic datarecorder.
However I am unbelievably impressed with you mounting a spinner on your benchtop setup!
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Elegant accelerometer installation.
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So now it is time for some more software, Alan came up with the idea to convert this logger into a timer. I had to get used to this idea because it makes my setup obsolete but I think it is a very good idea to make progress.
We need the following software:
- Wait for start loop when powered up, no logging, ESC out = 0
- Walk to Handle time of 18 secs after pushing start (stop) button
- pwm out at the desired setting
The logger works with a txt file for reading parameters, we should be able to use this technique to make the timer behave the way we want.
The beaty is that once the new software is created it will load itself automatically to the logger if you put the new software on the SD card. No special tools needed, just drag and drop.
Is there anyone out there capable to help us on the pwm for timer 2?
Once the basic timer is running we can develop logic that will add power depending the sensor readouts.