Rev 3 will be better - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 07, 2020, 07:42:53 pm
content: If you cannot design... be good at bodging...Have a good weekend!

author: Benta
author_rank: Super Contributor
timestamp: August 07, 2020, 07:53:59 pm
content: Haha! We've all been there (and will be in the future).

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 08, 2020, 09:00:12 am
content: Missed one

author: Miti
author_rank: Super Contributor
timestamp: August 08, 2020, 11:43:34 am
content: Quote from: NivagSwerdna on August 07, 2020, 07:42:53 pmYou’d be surprised, or not, but I’ve seen worse with very experienced designers on very complex boards. And those designers are still there and very valued after many, many years. If the board does the job, a couple of respins are normal and actually budgeted.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 08, 2020, 12:46:47 pm
content: Rev 3 of what loll

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 08, 2020, 03:15:04 pm
content: Ahah, yes this happens to almost every engineer.But but... still, I'm curious what you call "rev. 2" (current board) here. Was the rev. 2 already meant to fix issues you found in rev. 1, or was it an evolution with new "features", which introduced new "bugs"?Because obviously, in the latter case, well again that's relatively frequent. But in the former case, that doesn't look very good and probably meant you rushed rev. 2 before thoroughly testing rev. 1.Sure sometimes some issues you find may make it look like it's not worth it/or not even possible to test the board further, so you don't test it "thoroughly", but often this is still possible to test most of it with workarounds, and I tend to do that instead of multiplying the revisions. Of course that also depends on the cost and yield time.

author: phil from seattle
author_rank: Super Contributor
timestamp: August 08, 2020, 03:34:47 pm
content: Green wires are always faster than a PCB turn!As to V2 being rushed, is it possible that he discovered he needed to use Serial rather than I2C or some such? Maybe a little benefit of the doubt is a good thing? I supposed we all should strive towards the perfection that some of us obviously already have.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 08, 2020, 03:47:00 pm
content: Quote from: SiliconWizard on August 08, 2020, 03:15:04 pmIt's a trick I learnt whilst working on product development at IBM... Nobody trusts V1.0 of anything so start your versions at 2.0 and nobody trusts .0 so 2.1 is always the first revision. True story!

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 08, 2020, 03:53:30 pm
content: Quote from: NivagSwerdna on August 08, 2020, 03:47:00 pmLol, that's a good one. So your rev 2 was actually the first one?

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 08, 2020, 07:54:27 pm
content: Quote from: SiliconWizard on August 08, 2020, 03:53:30 pm2.1First one

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 08, 2020, 08:24:54 pm
content: Quote from: NivagSwerdna on August 08, 2020, 07:54:27 pmAhah. Which shows that the trick doesn't work. The first version is bound to have bugs whatever you call it.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 08, 2020, 11:36:32 pm
content: OK I'm getting close now... and seriously considering a PCB revision.(Note sure why this is 2.2... guess I changed my mind... this is my first PCB for this project)

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 10, 2020, 07:04:35 pm
content: It seems it was easier if you traced only power lines on PCB.Those copper PCB wires only make a mess.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: August 11, 2020, 02:04:06 pm
content: It took me ages to work out my fundamental error... the connector on the RHS is wired correctly... but when I laid it out I made a 180 degree error! (confused by the fact the board this mounts on has this oriented the 'wrong' way). It does work perfectly now.... so I will spin another board when I have a batch to send to China.

author: b_force
author_rank: Super Contributor
timestamp: August 11, 2020, 02:19:34 pm
content: You know what's the worst?When there is a serious error in the datasheet.Omg, that meant spending WEEKS on troubleshooting and calling back a whole bunch of boards + wasting time bodging them all.(and being lucky to be able TO bodge them)

author: TimFox
author_rank: Super Contributor
timestamp: August 11, 2020, 03:37:35 pm
content: Before retiring, my job had an engineering rule about how many wire mods could be tolerated before a new PCB was required. What are the current rules on this?