Sorry for my slow replay I propose that we create a bare carrier board with connectors for different SOC modules and different peripherals/storage
This approach would maximize the combinations that can be tested using a single base board I would propose that we create the boards stackable with distributed power and data lines to facilitate the testing farm application Best regards Alin On Mon, Sep 8, 2025 at 3:01 PM Alan C. Assis <[email protected]> wrote: > Hi Tomek, > > Thank you for attending the event. > > We will mix the two possibilities: we will have basic and most chips (and > low cost) soldered on the board and we will have connectors available to > people to test other modules. > > This way the board will be useful for testing purposes (to quickly and > eventually automatically tests) to detect issues and also for pragmatic > applications. > > BR, > > Alan > > > On Mon, Sep 8, 2025 at 9:49 AM Tomek CEDRO <[email protected]> wrote: > > > Thank you Alan for leading this great initiative and everyone > > paritcipating :-) > > > > Sorry I was on the trip yesterday, could only for a moment on a train > > station, then I lost connectivity :-( > > > > This DIMM DDR2 SO-DIMM connector is nice for the CPU board aka > > "compute module" using similar connectors :-) The only problem I see > > here is radio antenna connectivity this is always pain in the butt :-P > > I can see Sebastien commented about 1mm thickness of the PCB but this > > is not a problem this is standard thickness easy to manufature at home > > too :-) I use often 0.5mm 1.0m 1.5mm :-) Factories now can make 10 > > layers, flexible, translucent, all sorts of magic :-) > > > > Then the mainboard can be easily extended / replaced / upgraded for > > what is needed. For a long time (since ~1997) I am using this modular > > approach for various initial prototypes, where each chip has its own > > board and connectors that can be then connected with other boards > > breadboards etc. Its very popular nowadays :-) > > > > One question - do we want to solder chips on the mainboard or just > > provide conenctors for the chip-board? Having everything as module > > would make mainboard cheaper to manufacture, faster to solder, also > > chip cpecific boards will be faster and cheaper to manufacture, and > > most of all we would easily reconfigure / upgrade mainboard > > peripherals when needed even without soldering - we can then replace > > just one small board when needed. One disadvatage is signal integrity > > for high speed bus.. but it would be better than loose wires anyways > > :-) > > > > It would be nice if all boards are designed in a way they can be > > manufactured at home :-) I have pretty good LPKF cnc for pcb so I can > > test two layer/side designs. But also pcb making with laser printer > > toner transfer should be possible. Thus some DRC rules would be nice > > to define such as minimum track width 0.5mm etc :-) Probably for CPU > > board these will be smaller due to quite dense connector? > > > > We could then produce gerber / drill / cut files for the boards, pack > > them up on a single layout, and send to factory to get a bundle like > > 5x for low cost and then solder things up at home? Maybe ordering > > already soldered boards can be cheap too. It would be good to provide > > cos simulation from various places when things are ready :-) > > > > Thanks again! :-) > > Tomek > > > > > > > > On Sun, Sep 7, 2025 at 10:06 PM Alan C. Assis <[email protected]> wrote: > > > > > > Hi Everyone, > > > > > > Thank all participants of the meeting about the NuttX Standard Board. > > > > > > For those who were unable to attend, the video is available on YouTube: > > > https://www.youtube.com/watch?v=keZAZ8GiYzI > > > > > > Just a summary of our meeting today: > > > > > > - It was defined that we should use the DIMM DDR2 SO-DIMM. > > > Pros: It has 200 positions (pins); Low Cost; Easy to solder manually; > The > > > CPU/MCU Modules don't require a connector. > > > Cons: the CPU/MCU module needs to use ENIG ( > > > https://en.wikipedia.org/wiki/Electroless_nickel_immersion_gold) that > > is a > > > little bit more expensive than simple PCBs > > > > > > - In order to simplify the base board routing and avoid complexity some > > > high speed interfaces (LCD, Ethernet) will be in the CPU/MCU Module. > (but > > > the signals will be available in the connector (TBD)) > > > Pros: Simplify the board design; Avoid rigid rule of have only a single > > > Ethernet's PHY or LCD module tested all the time; > > > Cons: The CPU/MCU Module will end-up becoming more expensive because > > these > > > extra components > > > > > > - The Mainboard/Baseboard will have the most common sensors/peripheral > > > soldereds in the board and an expansion connectors (i.e. MicroBUS, > P-MOD, > > > MicroMOD, etc) to let users/developers test other devices. > > > Pros: Reduce final cost; Brings more flexibility > > > Cons: Increase the board size to support these expansion connectors. > > > > > > We should have a new meeting next week (Sunday) to decide which devices > > we > > > will include in the board, if you have suggestions to improve our > board, > > > please participate. > > > > > > BR, > > > > > > Alan > > > > > > On Sun, Sep 7, 2025 at 9:14 AM Alan C. Assis <[email protected]> > wrote: > > > > > > > Hi Everyone, > > > > > > > > For those who will participate in the design phase, please join in > the > > > > Jitsi, we will start in 45min: > > > > > > > > https://meet.jit.si/Developing_NuttX_Standard_Board > > > > > > > > BR, > > > > > > > > Alan > > > > > > > > On Sat, Sep 6, 2025 at 11:57 AM Alan C. Assis <[email protected]> > > wrote: > > > > > > > >> Hi Everyone, > > > >> > > > >> We will have tomorrow morning (afternoon/evening for merians A to M) > > our > > > >> first meeting about the NuttX Standard Board: > > > >> > > > >> https://www.youtube.com/live/keZAZ8GiYzI > > > >> > > > >> New to this subject? Ref: > > > >> > > > https://github.com/NuttX/nuttx_hardware/blob/main/Documentation/standard/index.rst > > > >> > > > >> Please join us to define which features we need to have in this > board. > > > >> > > > >> BR, > > > >> > > > >> Alan > > > >> > > > > > > > > > > > > -- > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info > > >
