Shop Learn
KISS Eval board (general discussion) — Parallax Forums

KISS Eval board (general discussion)

ManAtWorkManAtWork Posts: 978
edited 2020-11-11 10:24 in Propeller 2
Yesterday, I've routed the PCB layout of yet another P2 evaluation board. Unlike others, I've tried to keep everything to the absolute minimum so that cost and board size is kept small. (KISS = keep it simple, stupid) Features are:

* P2 with all 64 IOs available on pin headers
* pin compatible with P2 EVAL accessory boards
* 3.3V LDO, 1.8V SMPS, 5V in
* 512kB boot flash ROM
* NO SD slot
* NO video (onboard)
* NO hyper RAM
* prog plug connector for programming (NO USB onboard)
* fits on standard breadboard
* 25MHz crystal
* dimensions 30.5 x 76.5mm (3" x 1.2")

I know that this setup has some limitations. But if it doesn't fit your needs you can always buy a full featured P2 EVAL or a P2D2 (when available). But if there is enough interest I could produce between 20 and 50 boards for ~50$ each.
352 x 903 - 35K
«13

Comments

  • ManAtWorkManAtWork Posts: 978
    edited 2020-09-30 08:29
    Because of the double row pin headers a trick is required to use it together with a breadboard:

    You can solder single row pin headers into the outer row on the bottom size and into the inner row on the top side. The bottom pins go into column "I" and "B" of the breadboard and the top pins can be connected with jumper wires. JP2 (power supply) goes into columns + and -.

    To use accessory boards double row pin headers on the top side are required. If you need both you can use longer pins in the outer rows so that they are available on top and bottom.

    Can somebody confirm that the width of an accessory board is 20.3mm (0.8")? Do they fit if the gap between adjacent headers is 0.3" (2 pins missing at 0.1" pitch)?
    800 x 1047 - 167K
  • Nice design

    Only some of the accessory boards are 0.8". A few are 1.2", and the VGA/AV board is 1.3".
  • Count me in for a couple :smile:
  • Now you've got me interested. Again.
    I'd call it SimpleVersatileP2 (SVP2). An excellent starting point. I had better name for it but just didn't like the short of it (those connotations from the past long gone) ;). I'm considering opting in.
  • OK, I've just added a few testpints, XI/XO, 1.8V and ground pins for the scope. All schematic sub-circuits have been tested in my servo design so I don't expect any problems. PCB manufacturing and shipping takes 1-2 weeks. SMT assembly and testing say another week.

    I'll only provide SMT assembled boards. Because of the different pin header options everybody has to solder the THT parts by himself. And there will be no individual options. So if anybody needs a bigger ROM or a differen crystal she/he needs to take the soldering iron... Sorry, to save time I only took components I've already got in stock.

    I live in Germany, so shipping inside Europe will cost ~13€. Overseas shipping will be much more expensive so if anybody in America or Australia is interested it would be good if we could bundle shipping.
  • PropGuy2PropGuy2 Posts: 327
    edited 2020-09-30 15:28
    I checked your KISS Layout & design for the P2 and I like it. It does not have everything but we are engineers and we can figure it out.

    My only concern is the lack of a USB port, but these are not hard to layout on any user PCB, same with a VGA connector, etc. After market add-on boards are also available. Possibly add/include in documentation a sample PCB layout example for those who may want to copy & paste onto their own PCB, along with a BOM of required component parts. Question: You are using a 25MHz crystal, the EVAL board uses 20MHz crystal (any reason?)

    As for the width of the EVAL accessory boards. I have a EVAL Protoboard and it is 1.2" wide. The regular width is o.8" wide. This is not a problem because anyone using the KISS board probably has an EVAL board and has moved on to designing their own (production) product using the P2 chip. The KISS board has everything I need - and has the parts that I can not readily design & manufacture ie. I do not have a pick & place machine and reflow soldering ovens to do the fine pitch work ( I assume you have production equipment ? )
  • Well, I don't like that onboard USB programmer because...
    * It often did cause problems with the P1, resetting the propeller when it shouldn't
    * it costs money and board space
    * Windows installs a new driver instance for each board, so if I test 100 boards I have 100 VCP ports installed. After the 255th windows has a problem... you have to de-install them all manually
    * everyone I know already has a prog plug
    * I don't like micro USB connectors, they tend break or wear out

    I have 25MHz crystals in stock because it is the standard frequency for ethernet PHYs.

    Making the pitch between adjacent IO port groups 1.2" would make the whole board very large. I think it would be no problem to add a spacer if neccessary (a 12 pin female header with long pins formerly known as "wire wrap socket").
  • ManAtWork wrote: »
    * I don't like micro USB connectors, they tend break or wear out

    Ditto!

    It's early days but I just received a bunch of those magnetic adapters (aliexpress) and they seem to be OK. I decided to order a bunch more of a slightly different design and that actually swivel.
    I am surrounded by metal chips and so I have had to clean one, once. It's nice that if you are clumsy, like me, you can catch the cable with your foot and the phone no-longer goes flying across the room :lol:

  • ManAtWork wrote: »

    I live in Germany, so shipping inside Europe will cost ~13€. Overseas shipping will be much more expensive so if anybody in America or Australia is interested it would be good if we could bundle shipping.

    Since I will be stocking all of Peter's boards for North America distribution, I can add all your products for the same.

    PM me for additional info.

  • jmgjmg Posts: 14,662
    edited 2020-10-01 08:41
    ManAtWork wrote: »
    Well, I don't like that onboard USB programmer because...
    * It often did cause problems with the P1, resetting the propeller when it shouldn't
    * it costs money and board space
    * Windows installs a new driver instance for each board, so if I test 100 boards I have 100 VCP ports installed. After the 255th windows has a problem... you have to de-install them all manually
    * everyone I know already has a prog plug
    * I don't like micro USB connectors, they tend break or wear out
    I'm not seeing that Windows effect here ? - All the UB3 chips with the same flash content, connect as the same COM port number.
    I think windows needs to see change in the port ID info, before it increments.

    There looks to be room to allow for both USB and bare-wires power on your layout.

    I like the USB connectors with full stakes, as those are very sturdy, the one shown (below) is 4c/100, so has minimal cost impact.

    If allowing for 'bare-wires power', maybe choose a wider-supply regulators would be a safer choice ?
    291 x 286 - 146K
  • RaymanRayman Posts: 11,965
    I like the ap3402 for getting 1.8 v
  • Ok, wrong place, wrong time. It's already obsolete before it's finished!
    Watch JonnyMacs Edge Breakoutboard on Zoom.
    I quit. :(
  • ManAtWork wrote: »
    Ok, wrong place, wrong time. It's already obsolete before it's finished!
    Watch JonnyMacs Edge Breakoutboard on Zoom.
    I quit. :(

    Sad. It's your decision but, seems to me, a bit premature. You've already put some work to it and clearly described the board and the goals in the first place. I'm sure there is room for the board like this. Just give it some more time and people will come back asking for it.
  • @ManAtWork, do you have a link for JonnyMac's Zoom video? I'd like to take a look at it.

    I like the approach you were taking, and it would be good if you could continue to pursue it. I think the Edge is good, but I'm concerned about the connectors required to use it. A few days before you made your initial post I was thinking about something like what you were proposing. I think using 0.1" spaced pins would be better than using the Edge connector. I was thinking along the same lines as Peter's P2D2, but with a minimal amount of components like the KISS Eval board. You might consider two versions of the KISS board -- one with the Eval board pinouts, and another with just the 64 P2 I/O pins, and minimal ground and power pins. That latter version would be slightly shorter, and have fewer pins than the Eval board.
  • JonnyMacJonnyMac Posts: 7,568
    edited 2020-10-01 00:39
    @ManAtWork, do you have a link for JonnyMac's Zoom video? I'd like to take a look at it.
    I don't think it's up yet. Parallax decided my idea for a P2 Edge breakout board (see the Edge thread) was worthwhile and is running with it. Watch for today's zoom video to go up -- Ken and Chip talk about the board and the features they added to my original idea.
  • I thought there was a niche that has to be filled. And if I have an idea I prefer to just go ahead instead of asking everyone an doing marketing research, first. Often, I think, it's the better way but , of course, it also bears the risk to go into a dead end. Bad luck...

    If there's a product B that can do everything product A can do and B is better in every perspective then there's no longer any reason to continue to make A. And even if the Edge board takes a little longer and cost a bit more people will wait and pay for it because your signature is on it, Jon. I can't compete with that. If I stop now I loose a day of work. If I continue I'll loose more and nobody gains anything, IMHO. Making eval boards is not my main business. I have lots of other stuff to do.

    If anybody disagrees feel free to use the files attached.
  • But unless Digikey stocks it......the huge European market won't be interested in the ridiculous import costs.
  • Mr Man, welcome to the "wadda think o this" club :) Everyone has an opinion that it has "gotta have" and "should not have", but you can't please everyone, so just please yourself first :) Sure, take in some of the stuff but in the end you have to be pragmatic about it and get the darn thing done and dusted. My P2D2 started off as a reference design, then an actual board, and then it had to handle way more current and way more heat and way more everything and have huge confangled heatsinks and fans too. Before I knew it, after having gone one step forward and one step back each time, I'm still here! :( But there's a light at the end of this long tunnel mind you, as long as it's not the headlight of the train coming in the other direction!
  • @ManAtWork - I am certain there is a niche for a board you described in your initial post. But I agree with your approach. Seems very reasonable to me. Stop the development now, do not put more effort in it, and just wait couple of weeks. Once you get enough emails from people that actually need your board (as it is, no changes) then you may reconsider making it happen.
  • TubularTubular Posts: 4,346
    edited 2020-10-01 08:43
    Ken mentioned today that discussions with Digikey and Mouser are underway

    Two key points
    - your board is much more compact, about 4 vs 28 sq inches
    - EU made is important for EU, i believe
  • bob_g4bbybob_g4bby Posts: 200
    edited 2020-10-01 09:33
    A board aimed at hobbyists wants to be 0.1" pinned, so we can use it with veroboard, hand soldered sockets etc. and easily get scope probes on pins. The older enthusiast eyesight is something to consider too. Keeping it simple is admirable, the cost of trying out a P2 is lowest and the cpu remains uncommitted for as wide use as possible. The tax and import duty from the States to the UK is high, so that would need a fix. I want to easily add an ftdi, bluetooth, wifi or sdcard module bought off ebay to suit the situation. So I would say go for it, but be prepared for the chinese clones at some later date. You could sell both bare boards, kits and made-up boards. Thumbs up from me. Where it's made isn't so important, but how little it costs is. So I won't be buying a P2EVAL, although I wish Parallax every success in selling it into industry and getting the P2 used everywhere.
    cheers Bob, retired electronics engr.
  • ... but in the end you have to be pragmatic about it and get the darn thing done and dusted.

    Exactly. My servo project is still waiting for completion.

  • bob_g4bby wrote: »
    A board aimed at hobbyists wants to be 0.1" pinned, so we can use it with veroboard, hand soldered sockets etc. and easily get scope probes on pins. The older enthusiast eyesight is something to consider too. Keeping it simple is admirable, the cost of trying out a P2 is lowest and the cpu remains uncommitted for as wide use as possible. The tax and import duty from the States to the UK is high, so that would need a fix. I want to easily add an ftdi, bluetooth, wifi or sdcard module bought off ebay to suit the situation. So I would say go for it, but be prepared for the chinese clones at some later date. You could sell both bare boards, kits and made-up boards. Thumbs up from me. Where it's made isn't so important, but how little it costs is. So I won't be buying a P2EVAL, although I wish Parallax every success in selling it into industry and getting the P2 used everywhere.
    cheers Bob, retired electronics engr.

    Information leak... There will be a small 0.1" breakout adapter announced soon (if not already), part number #64019, which accepts the Edge and gets you to a breadboard or veroboard. I didn't see yesterday's Zoom yet, but if that wasn't included you will find it shown at the next Zoom. Item on target to be in stock November 1st, along with the Edge module.
  • Tubular wrote: »
    Ken mentioned today that discussions with Digikey and Mouser are underway

    Two key points
    - your board is much more compact, about 4 vs 28 sq inches
    - EU made is important for EU, i believe

    Both valid points.
    Man, that Edge thing will be huge at 28 sq inches. Easy to find on a cluttered desk but no fun when one tries to incorporate it into some actual commercial product if it ever comes to that.
  • VonSzarvasVonSzarvas Posts: 2,367
    edited 2020-10-01 11:10
    Maciek wrote: »
    Tubular wrote: »
    Ken mentioned today that discussions with Digikey and Mouser are underway

    Two key points
    - your board is much more compact, about 4 vs 28 sq inches
    - EU made is important for EU, i believe

    Both valid points.
    Man, that Edge thing will be huge at 28 sq inches. Easy to find on a cluttered desk but no fun when one tries to incorporate it into some actual commercial product if it ever comes to that.

    Commercial product could just include an edge socket, then plug the edge in direct- no breakout needed? That's one of the principals of the first edge module version- to be as low cost and simplified as possible, suitable for integration.

    Sorry @ManAtWork for going OT with your thread. I personally think your solution has it's own great merits- it's something I wanted to do as well; to extend from the FLiP design to make the FLiP2. Maybe one day that will happen, but if the community makes their own boards then that's brilliant too. There's always going to be different needs, and I think the more choices the better. Unfortunately it seems we all have far more ideas than time these days, but together we can move mountains silicon :)
  • Maciek wrote: »
    Tubular wrote: »
    Ken mentioned today that discussions with Digikey and Mouser are underway

    Two key points
    - your board is much more compact, about 4 vs 28 sq inches
    - EU made is important for EU, i believe

    Both valid points.
    Man, that Edge thing will be huge at 28 sq inches. Easy to find on a cluttered desk but no fun when one tries to incorporate it into some actual commercial product if it ever comes to that.

    You have to compare the Edge board against the KISS board without the breadboard. I think only the big breakout board is 28 sq inches. The breadboard in my picture is even bigger.

    The idea of the Edge, if I understood correctly, is to use both together for experiments and only the Edge board in the final product.

    When it's available at Mouser you can order it without paying customs fees and shipping will be cheaper than now.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2020-10-01 11:52
    bob_g4bby wrote: »
    A board aimed at hobbyists wants to be 0.1" pinned, so we can use it with veroboard, hand soldered sockets etc. and easily get scope probes on pins. The older enthusiast eyesight is something to consider too.

    Veroboard? Get outta here. While that was ok back in the 70's for discretes and the odd dip chip, I use matrix board with uncommitted through hole and plated pads on proper FR4 board thank you. That old veroboard would bend and tracks would lift or they would short because you didn't cut them clean etc. But 100mil matrix board is limiting anyway, which is why I am getting my 50mil microMAT boards made up. I know they don't come with octal sockets, but they suit smd components as well as through-hole and 50 and 100mil header pins. Even 10 years ago DIP CPUs were very hard to come by, so I think this mindset needs to change. The P2D2 has 100mil headers but they were taking a lot of extra room and besides, it was too hard to find low-profile headers for it. Now the P2D2 has two 44-pin 50mil connectors on a 1" row spacing, and it is feeling so much better for it. Mind you though, I can slap that slim P2D2 smd fashion onto a fat 100mil header board exactly like my last version, so you can have the best of three worlds, 100mil, 50mil, and smd.


  • MaciekMaciek Posts: 312
    edited 2020-10-01 12:41
    ManAtWork wrote: »
    Maciek wrote: »
    Tubular wrote: »
    Ken mentioned today that discussions with Digikey and Mouser are underway

    Two key points
    - your board is much more compact, about 4 vs 28 sq inches
    - EU made is important for EU, i believe

    Both valid points.
    Man, that Edge thing will be huge at 28 sq inches. Easy to find on a cluttered desk but no fun when one tries to incorporate it into some actual commercial product if it ever comes to that.

    You have to compare the Edge board against the KISS board without the breadboard. I think only the big breakout board is 28 sq inches. The breadboard in my picture is even bigger.

    The idea of the Edge, if I understood correctly, is to use both together for experiments and only the Edge board in the final product.

    When it's available at Mouser you can order it without paying customs fees and shipping will be cheaper than now.

    My bad then. I took the 4 vs 28 comparison for granted hence the comment. It pays off to pay attention to detail and verify things. Thanks for pointing this out.
  • MaciekMaciek Posts: 312
    edited 2020-10-01 18:35
    ManAtWork wrote: »
    ....When it's available at Mouser you can order it without paying customs fees and shipping will be cheaper than now.

    What really matters is the total cost (tax + shipping). With the Parallax brand on it I do not expect it to be even close to your offering. Time will tell.
  • JonnyMacJonnyMac Posts: 7,568
    edited 2020-10-01 18:01
    but you can't please everyone, so just please yourself first
    Indeed. My suggestion for the P2 Edge breakout/breadboard was based on what I'd like to have on my desk to work with the P2 Edge. Throwing around ideas is easy, except that they are not always understood. Knowing this, I sat down on a Saturday morning with my PCB program and some 3D models to make what I'd like to have crystal clear. Surprise -- it worked! Honestly, though, I thought I would have to make it myself (another reason I used a PCB program to "sketch" my idea. I didn't expect the reaction from Parallax, especially putting my signature on it.

    Here's the thing: Ken showed me their version and gave me one shot for feedback -- a lot of back-and-forth would make it impossible to deliver when they want to deliver it. Herein lies the problem with design-by-public-committee; it shreds schedules and you end up with people that aren't happy, anyway.
Sign In or Register to comment.