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Permalink Reply by Ben on May 31, 2010 at 1:32am

Hi, just thought I would post an update. There was no battery reading previously because there was no GPS lock. It is now printing out some value.

Some questions remain:

1) Apparently, I can use PSEL = servo and monitor the voltage level of the receiver by connecting the pin (A5) as per the manual instructions to the positive terminal of the output pins. Am I correct to say that?

2) Based on the above setup, can I still feed in an analog voltage from another battery to pin A5 to monitor the battery level, assuming that the ESC and the battery has common GND? What is the maximum voltage it can take? What is the role of the #define INPUT_VOLTAGE in the header file? If for example, my other battery (not the ESC) is a 12V battery, do I change the #define INPUT_VOLTAGE to 12000.0?

Appreciate any help! Thanks in advance!

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Permalink Reply by Ben on May 31, 2010 at 2:44am

Something weird happened. The Ardupilot board suddenly switched to baud rate 115200 from the original 57600 (i'm using EM406). What is the cause of this? How do i switch it back to 57600?

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ModeratorPermalink Reply by Chris Anderson on May 31, 2010 at 8:06am

Ben,

I'll try to help, but I'm a bit confused by what you're doing. The power monitor is designed to measure the voltage of your battery, not your receiver as you wrote. You should connect it directly to the battery itself.

It works the same whether you're using PSEL = servo or not.

I'm not sure what the max voltage is. 12v is probably fine.

I don't know what you mean when you say the board "suddenly switched to baud rate 115200". The only way it can change baud speed is if you tell it to do so in the code.

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Permalink Reply by Ben on May 31, 2010 at 8:34am

Hi Chris, thanks for your reply.

Regarding the power monitor, how does the board know what voltage to measure the input against? I do get the power indicator on the GroundStation GCS working, but the green bars are either full or empty even though the numbers do change.

As for "suddenly switched to baud rate 115200", what i mean is that previously, I was using serial monitor at 57600 baud rate to read the Ardupilot's output. Without changing any code that has to do with baud rate, somehow the serial monitor starting outputting strange characters at 57600 baud rate. I changed the baud rate to 115200 and I see the Ardupilot output again, albeit at a faster pace. The GPS is also unable to get a lock and just blinks (twice as fast) continuously.

Am I doing something wrong here?

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ModeratorPermalink Reply by Chris Anderson on May 31, 2010 at 3:02pm

Ben,

Assuming you uploaded the code right (see TimL's comment about using the latest version of Arduino and I'm sure you followed the directions about selecting the correct board in the IDE), I think this is probably something screwy on your PC. Nobody has ever reported this before, and we've never seen anything like it. I'd try another PC...

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Permalink Reply by Nathaniel Caner on May 31, 2010 at 2:30pm

Ben,

Check out this post I just made. I think it will help explain things. Check the attached schematic of the shield to see the circuit for the voltage divider in the upper left corner R9 and R8 are the controlling resistors.

Attachments:

• Ardupilot_shield_v21_sch.pdf')Ardupilot_shield_v21_sch.pdf, 17 KB
• Ardupilot_shield_v21_brd.pdf')Ardupilot_shield_v21_brd.pdf, 27 KB

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