Printed circuit board

[Cardo]

I know some of you do this kind of stuff day in day out, so I'm wondering if I could have some assistance...

This relates to our system to control various boat bits from a Pebble smart watch. We have a Raspberry Pi that is connected to a set of relays, which in turn can control various bits and pieces.

Unfortunately, the Pi can't be connected directly to the relay board, it currently goes through a bread board with a ULN2803A chip and some resistors to accommodate the difference in voltages (3.3v on Pi vs 5v on relay board), reverse the active low nature of the board, and also pull down any float voltages on the Pi's GPIOs so we don't inadvertently activate any relays on startup.

This is what it looks like:

and a closeup:

I'm wondering if it would be possible to get a simple PCB made up to make this neater and more secure? I'm guessing smothering the bread board with glue isn't the most ideal solution!

 

[Rigger Mortice]

"Veroboard", that's the brand name. Known generically as "Stripboard".

 

[John_d_Smith]

If you're only making one i'd use veroboard (stripboard) available at Maplins.

 

[John_d_Smith]

Snap!

 

[cliffdale]

A quick way would be to use some strip board. http://www.maplin.co.uk/p/3929-srbp-matrix-board-plain-jp54j

I would advise you to use an 18pin DIL. It will avoid heat damage to the IC when soldering.

Edit
Link for DIL

http://www.maplin.co.uk/p/dual-in-line-socket-18-pin-hq76h
Cliff

 

[bedouin]

google "prototyping board"

or googling ULN2803A reveals:

https://www.tindie.com/products/DTronixs/piio-minipiio-uln2803-add-on-for-raspberry-pi-pcb-only/

Probably loads more out there too

 

[Cardo]

Thanks, all. The Mrs is in the UK at the moment so I'll get her to pick up one of those strip boards and a DIL thingymabob.

The Minipiio looks nice, but unfortunately doesn't seem to account for the extra resistors to pull down the float voltages.