Search found 8 matches

by scott-42
Tue Aug 23, 2011 11:44 am
Forum: RBBB
Topic: Wrong 3V3 VR shipped with product
Replies: 1
Views: 4594

Wrong 3V3 VR shipped with product

I received 5 RBBBs with a 3V3 VR instead of a 5V version.

I would like to get the correct part sent to me.
by scott-42
Fri Aug 12, 2011 1:23 pm
Forum: RBBB
Topic: Electrolytic vs. Ceramic Caps
Replies: 1
Views: 4991

Re: Electrolytic vs. Ceramic Caps

My guess as to why the electrolytics are there is because the VRs specified ask for them in their typical application circuit diagrams (check the spec sheets for L4931 and LM2940). And I would further speculate that with the current design of the board to allow for multiple substitutions of the VR t...
by scott-42
Sat Jul 16, 2011 7:12 pm
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

I'm glad you got it figured out. :D I guess it was just time for the multi-meters to go out as one of mine also decided it was done. :( I also had to order a new one this week. Though mine was really abused in my younger years and I had fried the Amp reading portion of it a long time ago. Who knew c...
by scott-42
Fri Jul 15, 2011 10:28 am
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

If you have a resistance other than ∞ (infinity) from A5 to GND, then yes you have a problem. Either the solder joints are really bad and you leaked past the solder stop or the board is bad.

Have you had a chance to measure it and can you report the values?
by scott-42
Tue Jul 12, 2011 8:48 pm
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

A5, along with all the other analog pins, don't connect to anything other than the Mega pin directly next to it. For voltage to appear on A5, it has to have a short on the board to something and the only thing close is the ground plane. This is why I asked you to check the resistance between A5 and ...
by scott-42
Tue Jul 12, 2011 6:20 pm
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

Sorry I should have specified the part of the board I really cared to see. Link to Album This is the back of the analog pins. You can see a pinkish area around the pins where there is a ground plane. http://i.imgur.com/H79qD.jpg This is the top of the analog pins. Again you can see a slight outline ...
by scott-42
Tue Jul 12, 2011 10:31 am
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

Using a multimeter, check the resistance value between: 1. A5 pin and the GND pin right next to it 2. GND and 5V right next to the A5 pin 3. A5 and the 5V one pin over. Be sure to check with those specific pins and not some other place in the board that is labeled 5V or GND. Is it possible for you t...
by scott-42
Mon Jul 11, 2011 11:01 pm
Forum: RBBB
Topic: RBBB issue with I2C
Replies: 27
Views: 35607

Re: RBBB issue with I2C

Interesting, since you mentioned using two different types of VRs and two different packages (the kit only comes with one, the L4931 in TO-92), did you put them in backwards or use the wrong kind? I would guess that either something is backwards like the VR or you substituted parts like the VR and p...