I think I fried my rapiro board...

I was using a 12v 90w power supply and tried to connect a load to the 5V on the I2C pins.

I was connecting this because I noticed the output was not entirely stable:

As soon as I did, the board reset. Then it would no longer initialize/power on via the DC jack.

Any ideas what may have happened?

posted by evilbluechicken on 2014-05-07 03:21

Probably, Thermal shutdown of the LDO would worked.
See the Chart.
In this case(DC12V),LDO can source 0.5A.

Solution 1. Use 6V 30W class AC-DC adapter.(But I can't find the adapter in Japan.)
Solution 2. Use 12Vto6V Step-down converter, between the 12V power supply and DC jack
Solution 3. Use 12Vto5V Step-down converter.(See the block diagram. My Rapiro is this Solution. https://github.com/oga00000001/RapiroTools/tree/master/PowerSupply

Please look for similar Step-Down DC/DC converter.
http://www.aitendo.com/product/3851 (My Rapiro use this DC/DC)

posted by oga on 2014-05-08 21:51

So what you are saying is I put too much current load on the LDO and caused it to overheat? Because i was using 12V input vs 6V input?

I have a power supply that also has a USB out that I am using to power the raspberry pi. Should I remove the power pins coming from the rapiro board to the pi as well?

(It was working fine with those attached until i tried to connect the DC-DC converter to the I2C)

Also hello oga, I noticed you used my edits of the arduino firmware which were featured on the site for incorporating the distance sensor :D
As soon as I get my new rapiro board in, I'm gonna start working on auto walking and adding in object recognition...

posted by evilbluechicken on 2014-05-09 05:19

I think the cause of fried.
2.Thermal shutdown of LDO worked
3.Current source stop from LDO
4.Revers current or Ground bounce from boost DCDC. (Effect of L (boost DCDC)) ?
5. Abnormal voltage generation.
6. Damage to other devices

Boost DCDC, I think it only increases the load current, that there is no effect on the stability operation.

If you need power, I recommend that you use the other step-down converter.


posted by oga on 2014-05-11 09:30

( Allowed tags: <b> <s> <code> <blockquote> <img> . Automatic URL link.)

Uploaded image is placed to the bottom of the post. To add multiple images, make post once then edit the post.

Read Terms of Service upon submitting. 投稿する前に利用規約をお読みください。