Board Bring-Up Recipe

Board "bring-up" is the first time you apply power to a newly designed and manufactured PCB. It's something I've been doing for nearly 30 years now and is probably the most intense and rewarding part of my job.

Ground Rules

Work as a team: avoid blame. You'll need as a minimum a hardware engineer (probably the PCB designer) and a software engineer (probably the software lead engineer). Keep the team small and focused. Clear your schedule, get plenty of coffee: this may be a long day/night/nights!

Prepare

Make a minimal version of software for your first run: leave out as many bells and whistles as possible. A flashing light "blinky" demo or "Hello, World" on a terminal is perfect.

Get hold of quite a few PCBs: you're likely to fry the first ones and people will want to start using the others once they're running. However many you get you'll be using them all soon and will probably want more.

It won't work first time

My experience is that when you first apply power to a board it doesn't work. Use as low a current limit as possible and DON'T PANIC. Work methodically through the PCB finding out why it's not responding. Check components are placed the correct way around. Check transmit/receive lines are connected as you expect. Check your software doesn't depend on some component (e.g. a crystal or a pull-up resistor) that is present on the evaluation board but absent in the custom design.

You realise the problem

Generally something has gone wrong, often a misunderstanding between the hardware and software teams. DON'T PANIC. Work through the problem without blame: you're trying to achieve the same goal here.

You realise the solution

Don't be afraid to make a bit of a mess here. Maybe a nasty software hack, maybe hardware, probably both. The aim is to prove something works then pretty it up later. Progress rather than perfection and keep your eye on the goal rather than how you achieve it.

It's working!

Make detailed notes of what you had to do to make it work. Ideally save a software branch of your hacks to refer to later when you do it "properly". Everything you can should be recorded so that theoretically if you go off sick the next day another engineer can pick-up where you left off. You're pretty high on caffeine and adrenaline right now and you won't remember those details in the morning.

Celebrate

Go out for a beer or just watch the sunset (or sunrise!) with a last coffee and savour the moment. You climbed an intellectual mountain and it's time to take a break and enjoy the view.

Wash-up

Now is the time to have that meeting: bring management up-to-speed with what happened and an estimate of the effort to make a working product. Take time to show the junior members of the team what you did and why: they'll be doing this someday and probably sooner than they think.

Keep improving

Now that you have a custom board you can realise performance approaching the promises in the component datasheets. They always lie a bit economical with the truth so don't expect to achieve exactly the same numbers but if you're significantly out then this indicates that there are still improvements to be made. Don't tolerate higher current consumption than expected: this usually means something isn't working right.