Yeah I see it in the schematic but on the last board picture it looks like it goes to 5V in the bottom right of the picture. Is the silkscreen covering something I'm not seeing?
What is the purpose of the back powering diode ?
Wouldn't users simply tie 5V and 3V3 supplies together if powering from 3v3 only ?
Result is USB Switch is on, and Switcher is at 100% duty, so always on, and 3v3 LDO is either in saturation, or close to it,
Glad to be of service. You better double check for any other cases where your schematic and layout mismatch.
\
I've been busy wrangling with Protel99SE for the past week and it has been crashing and corrupting the library files. I try not to get too flustered about something like this but I'm certainly not happy about it. The area where it became VCC instead of VIO was probably because I had a VCC fill in there and this was one of the last mods I did.
What is the purpose of the back powering diode ?
Wouldn't users simply tie 5V and 3V3 supplies together if powering from 3v3 only ?
Result is USB Switch is on, and Switcher is at 100% duty, so always on, and 3v3 LDO is either in saturation, or close to it,
It was just an easy way to back feed VIN with something close to 3.3V from VIO so as to not load up the 3.3V regulators, in the case of wanting a simple/passive 3.3V WiFi programming dongle cable to be attached to P2D2 programming header and be powered in-system. Just adds flexibility and is not mandatory, just optional.
@Peter,
Great news the P2D2r2 is done, apart from the minor bug fix. Yes, I have found issues with ground and power planes with Protel. I’m still on an earlier Protel version although i keep thinking i should go to Protel 98. Then i think about my footprints and potential issues, and i just pull out the old laptop again
The Pi connections are a dog’s breakfast Seems they took a leaf from Arduino with it’s terrible connections. Why oh why do people design crappy connections instead of straight forward connections/connectors??? So thanks that the P2D2 has such nice sequential connections
Well it got a bit late to press the send button yesterday so I am doing that this morning after a few more trims. The gerbers look good and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
I don't need too many pcbs for the moment but it would be good to have extras for when the production chip comes out. The build time for 30 or less boards is 24 hours so I might go for 30 and DHL for ~$25 if I add the stencil for $6.
I've just sent it off as default green mask of the moment, I can always do another run.
...and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
..
We have used Black for boards that have thermal challenges, but it is not so easy to visually inspect, so for early samples Green is fine.
Did you order 2Oz copper ?
Great news. You guys worked really hard on this one! On the side - I *might* be willing to donate my one and only P2 Dev Board - *IF* you think you can safely unsolder it and put it on this P2D2 board. I have seen it done, but you need the right hot-air desoldering equipment, and even then it is somewhat risky. Just a thought.
...and now I am deciding if I will leave the soldermask green, or make it red or black and wait another couple of days. Any thoughts?
..
We have used Black for boards that have thermal challenges, but it is not so easy to visually inspect, so for early samples Green is fine.
Did you order 2Oz copper ?
The colour won't make a difference thermally, all soldermask is emissive in the far IR (a board with bare
copper would be much less efficient at radiating heat than anything with soldermask). Soldermask is also
important for receiving heat radiation in a reflow oven. Pretty much any organic material is highly emissive,
any bare metal is not (which is why heatsinks and power resistors are anodized - the anodizing visible light
colour is actually irrelevant)
Personally I find dark green soldermask boring and dull, which may just be a novelty-seeking thing.
Got an email about 3 hours ago to let me know that the boards and stencil have been shipped. So it looks like I will get it this Friday even though I only sent the artwork off lunch time yesterday. Unbelievable!
Now I just have to order the parts but they should be here Monday.
Peter, could you publish a new BOM for the latest layout? The last one I have is a few months old.
I will order the parts today so I am in the process of converting the raw bom across along with Mouser part numbers etc and I will post that as soon as I'm done.
My parts order to Mouser was sent a little late so now I have to wait until Mouser processes and ships the order. I'm hoping that despite the fact that it will be Tuesday here when that happens that I can still get the parts this week. Since I have a stencil I will immediately make up one pcb and check it quickly so that I can run off at least 10 pcbs although I think I have about 15 P2ES chips on hand.
I will post the BOM shortly and from there I can calculate a price. For anyone who wants/needs one there are some that have been waiting a while so they are at the top of the list. But hold off holding your breath until I complete my checks and make sure I have a working product first. But feel free to place a tentative order for one by posting here and the price will still be reasonable even though I badly need to cover my costs (except for Chip if he wants one)
Peter, glad you got your boards back. At first glance it seems okay and that silk numbering around pins is more readable now too, though the photos are not in perfect focus so it's a bit hard to tell. Are you still satisfied with the quality? Any PCB production issues that are noticeable?
Can't wait to hear how it goes once you build up your first one and get it working, then get a hold of one myself with any luck!
@rogloh
Hmmm, I didn't have much time so I just used one of the photos from my phone which normally are ok but I must have held it a bit close this time and the edges blur. Here's another shot I just did under less than ideal lighting.
The pcb production looks to be very consistent and high quality. Don't worry, I've got one of the first ones earmarked for you, I know you've been waiting a while
I believe that Chip wanted to order about 1000 or 1500 units (corrections anyone?!).
If those numbers are off, he definitely wanted to order a lot more than the first engineering sample since this should be the final product anyway.
How many of these will be available? Have they all been spoken for?
I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.
Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.
How many of these will be available? Have they all been spoken for?
I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.
Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.
Thanks. Once all of the people who missed out on the Parallax boards get theirs I will put in a request. I haven't had much time for P1 or P2 lately but I hope to get back to it soon.
How many of these will be available? Have they all been spoken for?
I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.
Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.
Thanks. Once all of the people who missed out on the Parallax boards get theirs I will put in a request. I haven't had much time for P1 or P2 lately but I hope to get back to it soon.
Me too please Peter,
But I think it is better if the "professionals" get theirs first,
Since I'm really a newbie to Spin....
I come and browse the forums and read a lot of the threads,
and it just gets me excited and ideas start whirling around in my one watt
Sadly my soldering skills are as good as my swimming...
I swim like a brick lol
I don't mind paying for parts, shipping and your time too if it helps
I popped down the coast and got my friend who has some fresh solder paste for the stencil to make up a pcb for me. Here is the intermediate result, I have to do some power up checks nice and slow and talk to the P2 via the 5-pin connector for the moment until I work out how to put USB serial code into the EFM8 chip. Obviously I seem to have the wrong reset switch on there and an led is missing but that doesn't matter at the moment. If all goes well I will have a quantity of boards ready next week.
Comments
What is the purpose of the back powering diode ?
Wouldn't users simply tie 5V and 3V3 supplies together if powering from 3v3 only ?
Result is USB Switch is on, and Switcher is at 100% duty, so always on, and 3v3 LDO is either in saturation, or close to it,
I've been busy wrangling with Protel99SE for the past week and it has been crashing and corrupting the library files. I try not to get too flustered about something like this but I'm certainly not happy about it. The area where it became VCC instead of VIO was probably because I had a VCC fill in there and this was one of the last mods I did.
It was just an easy way to back feed VIN with something close to 3.3V from VIO so as to not load up the 3.3V regulators, in the case of wanting a simple/passive 3.3V WiFi programming dongle cable to be attached to P2D2 programming header and be powered in-system. Just adds flexibility and is not mandatory, just optional.
Great news the P2D2r2 is done, apart from the minor bug fix. Yes, I have found issues with ground and power planes with Protel. I’m still on an earlier Protel version although i keep thinking i should go to Protel 98. Then i think about my footprints and potential issues, and i just pull out the old laptop again
The Pi connections are a dog’s breakfast
I don't need too many pcbs for the moment but it would be good to have extras for when the production chip comes out. The build time for 30 or less boards is 24 hours so I might go for 30 and DHL for ~$25 if I add the stencil for $6.
I've just sent it off as default green mask of the moment, I can always do another run.
Did you order 2Oz copper ?
The colour won't make a difference thermally, all soldermask is emissive in the far IR (a board with bare
copper would be much less efficient at radiating heat than anything with soldermask). Soldermask is also
important for receiving heat radiation in a reflow oven. Pretty much any organic material is highly emissive,
any bare metal is not (which is why heatsinks and power resistors are anodized - the anodizing visible light
colour is actually irrelevant)
Personally I find dark green soldermask boring and dull, which may just be a novelty-seeking thing.
Now I just have to order the parts but they should be here Monday.
I will order the parts today so I am in the process of converting the raw bom across along with Mouser part numbers etc and I will post that as soon as I'm done.
- is it possible to buy the P2D2 board anywhere?
- where can i buy a P2 chip?
thanks for your time
I will post the BOM shortly and from there I can calculate a price. For anyone who wants/needs one there are some that have been waiting a while so they are at the top of the list. But hold off holding your breath until I complete my checks and make sure I have a working product first. But feel free to place a tentative order for one by posting here and the price will still be reasonable even though I badly need to cover my costs (except for Chip if he wants one)
Can't wait to hear how it goes once you build up your first one and get it working, then get a hold of one myself with any luck!
Cheers,
Roger.
Hmmm, I didn't have much time so I just used one of the photos from my phone which normally are ok but I must have held it a bit close this time and the edges blur. Here's another shot I just did under less than ideal lighting.
The pcb production looks to be very consistent and high quality. Don't worry, I've got one of the first ones earmarked for you, I know you've been waiting a while
If those numbers are off, he definitely wanted to order a lot more than the first engineering sample since this should be the final product anyway.
J
https://forums.parallax.com/discussion/170139/p2-final-release-date#latest
I have up to 15 of the P2ES chips so I will p(r)opulate the boards and perhaps 2 or 3 myself. There are a handful spoken for but you don't have to commit, just put your hand up. No matter what, I am sure they will all find a nice home. There are a few that I will give away just as Parallax did with their eval boards and the rest for a reasonable price. The P2 chips are not part of the costing btw since they are free samples from Parallax.
Of course, these same boards will be used with the production chip too although I will order more and probably with a red solder mask.
Thanks. Once all of the people who missed out on the Parallax boards get theirs I will put in a request. I haven't had much time for P1 or P2 lately but I hope to get back to it soon.
Me too please Peter,
But I think it is better if the "professionals" get theirs first,
Since I'm really a newbie to Spin....
I come and browse the forums and read a lot of the threads,
and it just gets me excited and ideas start whirling around in my one watt
Sadly my soldering skills are as good as my swimming...
I swim like a brick lol
I don't mind paying for parts, shipping and your time too if it helps
Thanks