-->
Page 1 of 3

Breakout Boards

PostPosted: Tue Jun 16, 2015 6:23 am
by ichilton
Hi,

I've got some breakout boards, like the ones in this ebay auction:
http://www.ebay.co.uk/itm/171822251755

There is some odd stuff about it though.

It's pulling GPIO15 down to ground through a 10k resistor, which seems sane.

It's pulling CH_PD up to VIN (???) via a 10k resistor - this should surely be to Vcc?

It's connecting VIN to GPIO13?

It's shorting Vcc to VIN through what seems to be a 0k resistor (labelled 000 and measures direct with a multimeter)????

Anyone any idea what's going on / intended here?


Also... what's a suitable regulator? - would a AMS1117-3.3 V 0.8A SOT-223 LDO work?

They've also not left pads for capacitors next to the regulator - will it likely be unstable without them?

Image of the boards:
Image

Thanks,

Ian

Re: Breakout Boards

PostPosted: Tue Jun 16, 2015 3:35 pm
by tytower
Can't see a Vin
I use a small piece of veroboard and some solids between

Re: Breakout Boards

PostPosted: Tue Jun 16, 2015 3:51 pm
by ichilton
VIN is the input of the regulator.

Ian

Re: Breakout Boards

PostPosted: Tue Jun 16, 2015 6:21 pm
by spants
Hi Ian. I use these boards in my project.

If you connect 3.3v to vcc the board works fine. You can put a voltage reg onto the position on the back of the board to power it at 5v. I bought the ams1117? But they are the wrong pinout for that position.
All was not lost as you can use it by cutting a track and positioning carefully. Not recommended though.
I now use an offboard regulator on vero board as I needed multiple gnd and vcc points.

High Quality 10Pcs/lot 5V to 3.3V For DC-DC Step-Down Power Supply Buck Module AMS1117 LDO 800MA Free Shipping
http://www.aliexpress.com/item/High-Qua ... 41751.html
(from AliExpress Android)

Don't know about the gpio connection. I seem to remember something needing it held high. It may not be vin but rather vcc as the pinout is not for ams1117
Tony