First attempt at PCB design

Hello Rob,

Your .pdf of the schematic hasn't worked very well, it's been chopped up into multiple pages. If you could set up your PCB CAD system to convert it to a single page .pdf it would be possible to look at it without printing and sticking bits together.

MK

Ah, my apologies, looks like my printing settings didn't get carried over. I've updated the link now.

// Robb

Hello, Would like to make some 'hobbyist level' PCBs and haven't made any for many years now. Since the day's that I was an electronics hobbyist (really want to get back into the subject though) Is there anyone on here that can make any recommendations on PCB layout software that is either reasonably inexpensive to buy failing that (and better still) downloadable under an Open Source license please?

Also are there any PCB manufacturer's that are willing to help hobbyists with their PCB needs as opposed to having to go to large scale manufacturer's of whom probably won't sell to end users only to volume buyers?

Are you making some form of weather station Robb? Sounds interesting anyway.

Hope I've not asked the above questions in the wrong thread. Should a new thread really need posting I've no problems with an administrator moving this post as necessary. Thank you.

I'm using Eagle free edition for this layout, I've found it relatively easy to use. The project is to battery power these and deploy them into a building to measure various environmental variables then collate and analyse the data.

// Robb

Hi Robb,

Thank you for the recommendation - Much appreciated (is this easy to use for newcomers?)

The project sounds fascinating. I'd love to build a RaspberryPi based weather station and understand that CPC are considering obtaining the PCBs for the AirPi weather station shield (possibly the full kit too but am not 100% certain about this).

Best Regards.

As I said, this is my first attempt at designing a PCB, I've found it relatively intuitive to use, there a few quirks that I quickly found out by studying existing schematics and board designs. but I found it quite easy to cobble this together from the existing schematics for the dev boards that I used in prototyping it.

// Robb

Your schematic isn't very easy to follow - I would usually try hard to avoid the "pin list" format where there are few wires and you have to go hunting for names all over the sheet. I usually break the processor up into several blocks where I've arranged the pins for convenient drawing. It means I don't use library parts and I end up with a new processor component for every new project - but I think that's a small price to pay for the readability that goes with it.

You could try adding more notes to the schematic - I don't know what half the circuit blocks are trying to do so I can't comment except in the most general terms.

I can't see any pull up resistors on the I2C bus  - these are essential and I doubt (but haven't checked) that the process has them built in. There is no standard value for these, you can read the NXP (its their bus) i2C spec and work them out or start with 2k2 and see if it works.

I also notice that you have GND and AGND - where are they connected and why are there two of them.

Finally, well done for using the Cozir CO2 sensor (a fine part made in Cumbernauld near Glasgow by GSS) - I was involved in the design of the electronics and software inside it

MK

Hi, Can you make any recommendations where a PCB manufacturer is concerned please?

Thank you.

Robb;

Check us out at www.sunstone.com for board fab for your design, for a variety of reasons. Some of these may be important to you, and others may not, all depending upon what you want from your project:

• Without anything more than your schematic and the .brd file, it would look like your board is a candidate for our VALUEPROTO service. 5 day turn times on 2-layer boards, as low as $28/board.  There aren't a lot of bells and whistles in VALUEPROTO, but you get boards built to the same quality level as all our Sunstone service levels. You can quote it yourself at www.sunstone.com to see what your actual pricing would be

• Alternatively, if you need faster turn times than 5 days, higher quantities, or a multilayer, then try quoting your design on our PCBexpress prototyping service. Your boards will cost a bit more than VALUEPROTO, but you get a lot for the money from PCBexpress. Online quoting at www.sunstone.com
• Try ordering your board from inside the EAGLE CAD program. Sunstone is represented there; you can send your board to us from inside EAGLE. Doesn't get any more convenient than that.
• Prefer NOT to order from inside EAGLE? No worries! You can export to Gerber files, or you can send us the EAGLE native design files. We build from EAGLE files all the time.
• Check closely on sunstone.com, you'll find a beta version of our new  DFMplus utility. Submit your design files to us via DFMplus, and we'll send you a detailed report identifying any potential issues with your design that could turn into electrical issues or the like. Get some peace of mind BEFORE you plunk down the cash for the board build.
  
• Our pricing is competitive, but our service is top-of-the-industry. For VALUEPROTO and PCBexpress, we offer a 100% on-time guarantee. If we can't get the ENTIRE order to you by the expected delivery time, we refund your order 100%. No questions. No hoops for you to jump through. If we're late shipping your order, it's on us.
  
• Need a little assistance? Want to talk to a person to make sure you're doing it right? Looking for a verbal walkthrough of what happens at a board manufacturer after we receive your order? Want us to place the order FOR you? No problem there, either. Just call us 24/7/365 and talk to one of our in-the-factory customer service staffers. They can take care of you.
• And, as you can probably tell by our response, we spend a lot of time interacting with the PCB and electronics design community both face-to-face an in the forums/social media. We work hard to be like an extension of your design team.

There are a lot of adequate fabricators out there; only one or two world-class solutions providers. We're one of them. We won't be the cheapest, but we won't be the most expensive. What we WILL be is the highest quality overall.

Hope this helps.

Nolan Johnson

Thanks for the reply, I'm just wondering if you have a sevrice for idiot checking, IE "You realise all your vias are too small to work" or "your ICs can't have tracks under them" These are the two main concerns I have with the design at the moment. I've got the latest version uploaded, re-laid the power supplies to make them neater and with wider traces.

Board

Schematic

// Robb