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Forum Index : Microcontroller and PC projects : OSHW and business
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MicroBlocks Guru  Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I want to ask opinions about OSHW (Open Source HardWare) and when to use it. At the moment i am considering putting a OSHW logo om my PCB's as that is what i think is the best way to promote my product. It is however difficult to judge if this is a good decision from a business standpoint. If i want to make the product reasonably priced i would need to order in bulk. Parts and especially PCBs are a lot cheaper. The plan is to sell the products in "only pcb", "kit including all parts', 'fully assembled' and as a 'Blox'. 'Blox' is a fully assembled pcb mounted in a plastic or aluminum box ready to be used for prototyping in combination with other 'Blox' and breadboards. Next to that i would like to offer electronic parts, cables, boxes etc that complement eachother and can be useful for customers to combine shipping costs and have some spare or extra components. In short it would be like Sparkfun but then with my own products as a basis. If i put everything like schematics, PCB layouts etc on line right away the chance that someone just plucks it of the internet and starts selling them too is quit big. It is not that i want to prevent that, but delaying that seems a good strategy. My idea now is that i would do the first batch without the OSHW and only publish the schematics. And when i have recovered the costs publish the pcb layouts and release it as a fully OSHW product. Most of the work has been in developing the concept and designing the pcbs. Recovering time is not my concern only recovering the costs for materials and initial bulk orders. What do you think? Microblocks. Build with logic. |
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kiiid Guru Joined: 11/05/2013 Location: United KingdomPosts: 671 |
TZA, we are both on the same train, probably there are many more as well 
My opinion: open hardware is not dangerous, open software however - is. If you publish schematics, even pcb layout, although that in many cases is not even necessary, chances are that very few people will actually jump in and start copying your circuit instead of just buying it already manufactured and save all the hassles. So, don't be afraid of the open hardware, there is always some risk of course, but hey, is there anything without? Unfortunately not everyone plays on the same set of rules and we have to adapt. http://rittle.org -------------- |
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graynomad Senior Member  Joined: 21/07/2010 Location: AustraliaPosts: 122 |
You will note that the Arduino guys played the Due cards very close to their chest until it was released. Partly I suspect that was because they got burned with the Uno, there were clone Unos on the market before theirs :) Even now the published design files are clearly not 100% the same as the actual product. Rob Gray, AKA the Graynomad, www.robgray.com |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3663 |
The thing I personally hate is when there are no schematics (I won't buy) or they don't match the actual product (when I get REALLY MAD and won't EVER buy again). John |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Just last night we found another error in the Arduino Due schems, nothing that would stop it from working but you have to wonder about the accuracy of the released files and the reason they aren't correct. Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Schematics are a must. Schematics are the basis for a PCB anyway. I use Diptrace and plan to publish not only the schematics, but also have the datasheets, Component definition, Patterns 3d model of all the parts used and if it is a microcontroller also the firmware files. When making small modules the schematics are actually not where the most costs are. And i would certainly not mind someone making a homebrew version. Publishing the PCB however makes it very easy to just pluck of the site and make an exact copy. Maybe i should follow Geoff's example. In that case it is open for the ones that register and agree to not blindly copy but use it for study, hobby or wants to add modifications. Microblocks. Build with logic. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Your right about the schematics, and also a proper BOM. Most schematics do not have enough information to replicate the circuit, often there are a dozen variations of a component but the schematic will just have the generic part number. It's very common for example to see a diode on a schem but no more info, what current, what Vf and Vr, what wattage etc etc. IIRC the OSHW mob defined that you have to release everything in a format suitable for use with free tools. sh*t yeah like I'm going to re-enter everything into Eagle or whatever just to make life easier for the cloners. As far as I can see, despite Arduino being the pin-up boy of the OS movement, technically I don't think their hardware is OS. I think a good compromise is to release the schematics in whatever format you use plus PDFs. That way people will not be orphaned entirely if you stop supporting the widget, admittedly it will be hard for them to make copies but at least it will be doable with some work. I do not think I will release the PCB files or gerbers, if someone has a good reason to have them, say they want to make an improved version, that's ok but why make it too easy for someone to clone your work with no effort. Let's face it, if you sell bare boards why would anybody want to make their own unless they are cloners who just want to undersell you. You can't stop that but no point making it any easier. I've also heard of SW and HW being placed in escrow, that way it's not in the public domain but if the parent company goes out of business the design becomes available to clients. So I think I'm voting for sort of 50% OS, release schematics but not BOM or PCB files, my design isn't finished yet though so I still have time to mull this over. Rob Gray, AKA the Graynomad, www.robgray.com |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3663 |
Olimex release searchable PDFs of their schematics - very useful when I can't figure out something. However, they're rather pale grey (gray) at times :( Have a look at a few and see what you think. They're all on their site. John |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I just read this: http://www.pololu.com/blog/27/thoughts-on-open-source-hardwa re Still processing...... Microblocks. Build with logic. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
TZAdvantage, I started reading that at 1:30AM then realised how long it was, that's a tomorrow job I think. JohnS, likewise for the Olimex schems Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Olimex shows the OSHW logo with products where they also publish the PCB layout. Others without the logo have a user manual and schematic. I think that is a good way to do it. For very simple circuits including a PCB layout would not be a problem at all. Microblocks. Build with logic. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Good article by the Pololu guy, I still don't know which way I will go but full OSHW is probably not for me. I don't mind releasing the information but last I read the OSHW rules it was too restrictive. The Olimex PDFs seem pretty clear, better than most Eagle schematics I've seen, there seems to be something about Eagle that encourages unreadable schematics :) Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I use Diptrace and the schematic design process is very flexible. A consistent look is possible using templates and discipline. As an example i have the schematic for the MCU32MX795 Blox and using that as a basis for a CMM Compatible Blox Still work to be done for the templates as all the table fields on the top and bottom are not really necessary. Also some parts need to be defined better so that the part values are always printed and clear. They now are sometimes difficult to place when a part is horizontal or vertical. The pin numbers for resistors and capacitors should stay hidden as those are only for the programs internal use. Ironing out those kinks should not be problematic. It is coming along slowly but steadily. Microblocks. Build with logic. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Yes that Diptrace scheme is pretty clear. Any reason the LEDs and their resistors have their positions swapped? Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
In the layout on the PCB i needed to switch it around because resistor pins are as far as i know in Diptrace not interchangable, they should be, i think i just did not find the way to do it yet. Every package has their own way of doing things and it takes time to find all the options. When you back annotate the PCB layout to the schematic the lines were crossing and i swapped them to make the schematic 'nice again'. That is already 'fixed', i just needed to rotate the resistor and update the pcb with the schematic changes... Learning all the time...
It is probably easier then that, but that means i have to read the manual. Microblocks. Build with logic. |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I updated the schematics: TZBlox MCU32MX795 and using that as a basis for a TZBlox CMM Compatible I think i found my schematic 'style'. A4, landscape so that it can be printed easy. Also on widescreen display it is much easier to read then a schematic in portrait mode. I have chosen the symbols for resistors and capacitors. Left out all the numbers that are not necessary and divide everything in functional blocks. Many others do it similar, getting it done in your own schematics program and have a consistent look is not easy. Now that i have a template, i would like to hear opinions if i left out something or if you find parts of the schematic that are not clear enough. Other files for the components used, their patterns, pcb landings and 3dmodels will also be available, i just need to make a template for that too. And lots of time to make it. :) Microblocks. Build with logic. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Looks pretty good, I have a couple of comments. All your points re orientation and size are correct IMO. U1 is missing pin numbers. Some junctions do not have dots, that's some PCB rework waiting to happen. Do all those nets (RAn, RBn etc) go to another sheet? If not they shouldn't have net names. After 30 years in this game I still have to think about VCC, VDD, VSS, VEE etc. I know most chips still use those names and sometimes they can't be avoided, but they are not intuitive, 5V, 3V3 are. Is it possible to change the direction of the arrows from the CPU? If so they should show the direction of the pin, ie input, output or IO. Overscores on net names (MCLR) often cause problems when the name is right under another net as the overscore merges with the above line. There are a couple of non-ambiguous ways to show an active-low signal with # probably being the most common, eg MCLR# Underscores should be avoided for the same reason, just in case you feel the need for them one day :) If you are going full OSHW then certainly you need a BOM that details everything appropriate about each component such as full part number, package type etc. Footprints and 3D models should not be necessary but gerber files are. BTW, the photo links on http://tzblox.com/Documents/_TZBlox_/CMM appear to be broken, might be a temporary thing. Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
Thanks for taking the time. I appreciate the comments. |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
I use the same symbol for AGND and GND,same as you do and they are labelled so there's no confusion. Chassis ground is usually a bar with a few angled lines, sort of ___|___ / / / / / What format, STEP seems to be the most common. Yes, I was happy to go to a PCB a week back until I found someone to look over the design, we're still making changes :) Rob Gray, AKA the Graynomad, www.robgray.com |
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| MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I use Sketchup for the 3d models. Not many export options. I think i can use some other 3d programs to convert it. Diptrace uses vrml. I have updated the schematic again.http://tzblox.com/Documents/_TZBlox_/MCU32MX795A I now used the parts function to be able to draw all the functional parts of the PIC32 seperate. It clears things up a lot (i think) and no more searching on the schematic for net names. (On that link you have also 2 links that have a rendering of the current 3d model of the module. The header pins are not nice yet, it takes some work to get it right.
Microblocks. Build with logic. |
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