Replies to This Discussion

DeveloperPermalink Reply by Doug Weibel on March 21, 2010 at 7:05am

Hi Nate,

I don't have a direct answer for you, but nobody else is chiming in....

You should be able to power it with 7.2 v at the Vin pin. Not sure why that is not working for you. Where are you attaching the ground? I believe Vin has two adjacent pads and perhaps you have confused the two as being Vin and ground?

I am powering mine with 5 volts which I input to the serial port (on the side with 14 pads). Why there? No particular reason, but it works for me. Using 7.2 volts you should only input it through the Vin connection though as it will need to be regulated down to 5.

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Permalink Reply by Nate on March 21, 2010 at 9:59am

Hi Doug,

According to the schematic (JP1), I assumed the pin next to VIN>6V was ground.
Nevertheless, I just checked that when I do plug in there, I don't get power on the board, so I must have read the schematic incorrectly....

So which ground connection should I use?

How do you know which pins are valid inputs for voltage?

How did you guys figure this out?!

Thanks, Doug.

-Nate

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Permalink Reply by Ken on March 21, 2010 at 6:26pm

Are we reading the same schematic? I don't know what "VIN>6V" means pin wise. Are you sure that isn't a hint that Vin needs to be 6v or more at the input to the first (5v) regulator to ensure it has enough voltage to operate?

Q: How do you know which pins are valid inputs for voltage?
A: Input pins on voltage regulators are always a good clue. "VIN" is a good clue.

JP1, pins 1 & 2, are where non 5V DC power goes in. Look -- Pin 2 goes to the INPUT of the 5V regulator, pin 1 is ground.

Your other question -- No, on the V2 board the power pin of the SPI connector (JP6) is on the 3.3v line, but the power pin on the serial port connector (JP3) is 5v which can feed the CPU and the 3.3v regulator. (On the V1 IMU+, I think you can use the power pin of the SPI connector.)

In theory you could connect the ground to any ground pin on the board, but reasons of trace width, routing, decoupling caps, etc. make it more better to use the ground pins on a connector that was meant as a power feed:

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DeveloperPermalink Reply by Doug Weibel on March 21, 2010 at 7:11pm

Nate, Ken is correct about JP1. I didn't look at the schematic, just the silk screen which is not entirely clear.

Just to back up a bit, I assume that the board works when you power it with a FTDI cable, correct? If that is the case and you get nothing when connecting 7.2 to Vin and ground, possibly you have a bad regulator on the board.

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Permalink Reply by Nate on March 21, 2010 at 8:11pm

Thanks for following up, Doug. I was just being stupid. I'll blame it on not-enough-sleep.

Sorry for wasting your time on this.

-Nate

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Permalink Reply by Nate on March 21, 2010 at 8:07pm

Hi Ken,

You are right. I do not see VIN>6V on the schematic, although that name is in the artwork on the board. So that's where I applied unregulated power. Without the lable JP1 on the board, I was pointing out that I assumed that the two pins labeled as VIN>6V on the board were VIN and GND of JP1.

It turns out I was making a retarded mistake and had the polarity swapped on my connector.

I've attached a picture of the correct way to do things, in case other people are foolish like me.

Thanks for your time,

Nate

Attachments:

• ArduiIMU_Power_Connection2.jpg, 304 KB

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Permalink Reply by kasra.mirshamsi on September 10, 2012 at 1:25am

Hi everyone, I really want to know If I wanted to supply power to my APM v1.4 through VIN pin using a 7.2v adaptor then what shoudl be the max current (amp) of the adaptor ?

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Permalink Reply by kasra.mirshamsi on September 10, 2012 at 1:11am

Hi everyone, I really want to know If I wanted to supply power to my APM v1.4 through VIN pin using a 7.2v adaptor then what shoudl be the max current (amp) of the adaptor ?

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