Hi Tomek, Thank you for those nice suggestions.
1) Yes, even some companies like Freescale (now NXP) used that idea in the past, i.e. DEMOQE board: https://www.nxp.com/docs/en/user-guide/DEMOQE128UM.pdf The MCU module boards need to have a minimum size to fit the connector and also we need to think that some MCUs have a "big" package like LQFP176 for example. In this case we are going to use 2 100-pin connectors, the same used on Raspberry Pi CM4. This connector is low cost and has many pins. 2) Yes, this is something we should have in the board to support sensors, modem, etc. mikroBUS and Pmod will be used, but we can think about using others as well. 3) The baseboard will have a USB/Serial interface to connect in the computer, at the moment we didn't know about include a programmer on it to avoid increasing boards, the idea is just using JTAG/SWD/ISP connectors. Remember that this baseboard will be used not only for ARM, but also RISC-V, AVR, etc. 4) The connector will be unique for all MCU modules, but we will have two connectors: the first one is Required and will have all signals common between almost all MCUs (UART, SPI, I2C, GPIO, etc), the second will be Optional and will include signal present on more "advanced" MCUs: Ethernet, Parallel LCD, USB, I2S Audio, etc. I moved the project to: https://github.com/NuttX/nuttx_board_std but I don't know if all people will see it or only those that are part of the organization. BR, Alan On Tue, Jun 10, 2025 at 12:26 PM Tomek CEDRO <to...@cedro.info> wrote: > Aaah! NuttX BaseBoard is more self-exlpanatory thanks Alan! :-) > > I played like this in the 1990's with 8051 but instead having one > single board I created separate modules that were attached with 2.54 > wires and f/m-connectors this allowed me to reuse different modules > with different boards and applications. This is now called Arduino > served with modules on breadboards :-P > > I have many MCU boards on a wall of medium size breadboards (SYB-118) > connected over 16 port USB HUBs, some observations below that may give > some hints on the BaseBoard: > > 1. Some boards are bigger and takes unnecessary space for just MCU > testing, so tiny MCU boards are the best (like XIAO series). Several > small MCU boards can fit on a single breadboard, while big boards > (i.e. STM) needs to use two breadboards. Small increase in size of a > breadboard is big increase in price, so I bought 100x SYB-118 as the > compromise between size and price (these also have mounting holes). > > 2. We may want to have slots for different peripherals (i.e. several > stdandars I2C slots for sensor boards). Peripherals switching is > problematic and in perfect situation with my current environment I > would like to be able remotely re-route MCU board to a specific > peripheral that would allow testing. I know this is extremely > problematic but I do not know any solution like this, except using > digital mux, opto-isolators, or relays. Voltage levels are also > problem (i.e. 5V vs 3.3V vs 1.8V). But using isolators may be a kind > of "adrressing" solution too (i.e. #EN pin).. except those isolators > are expensive. > > 3. Debug probes are best when these provide JTAG/SWD and UART over > single USB connection. I found STLINK-V3MODS > (https://www.st.com/en/development-tools/stlink-v3mods.html) to be > most versatile (it provides JTAG/SWD and UART but also additional > interfaces like SPI/I2C/UART/CAN) cost ~$10 and is meant to be mounted > as module on a target board (pin raster is 2.0mm not 2.54mm > unfortunately). But its commercial and closed-source. > > 4. Pinouts and Adapters seems necessary as different MCUs will differ > in size and pinouts to be attached to a single baseboard. Here I found > different boards use male pins on top of the board, some use male pins > on the bottom of the boards, some use female connectors, either 2.54mm > or 2.0mm or even smaller raster. From my experience what is rapidly > changing / easy to replace (i.e. cables, small boards) should use male > pins, while rarely changes parts (modules, boards) should use female > connectors. Female connectors usually go up, male goes down. Best > raster is 2.54mm as most popular cheap and easy to handle. Its very > nice when each pin have two holes for additional up/down conenctor > (i.e. you want to attach arduino shield from top to female connector > below, but also want to solder additional pins to then stick the board > to breadboard below). I know this seems trivial but when you have > different boards to physically manage sometimes its a problem :-) > > Have a good day :-) > Tomek > > On Tue, Jun 10, 2025 at 4:02 PM Alan C. Assis <acas...@gmail.com> wrote: > > > > Hi Tomek, > > > > The idea is to have a baseboard that could be used with different MCU > > modules, similar to Mikroe Fusion ARM: > > https://www.mikroe.com/fusion-for-arm > > > > But in our case the MCU modules are not limited only to ARM. We could use > > any MCU currently supported by NuttX, because the common signals (UART, > > SPI, I2C, etc) are exposed at the same position on that connector that is > > plugged in the baseboard. > > > > This way, instead of having a different process to test each board we > will > > test the baseboard in the same way, no matter what is the MCU module > used. > > > > BR, > > > > Alan > > > > On Mon, Jun 9, 2025 at 6:22 PM Tomek CEDRO <to...@cedro.info> wrote: > > > > > Thanks Alan :-) > > > > > > It would be nice to have a template for new boards along with > > > documentation, and maybe update existing boards when some standard is > > > ready :-) > > > > > > https://github.com/acassis/nuttx_board_std - I get 404 here o_O > > > > > > I have question here, when looking at STM32 mcus/boards these seem to > > > have lots of separate implementations, that are a bit inconsistent, > > > and usually confusing to newcomers (and to me too). Some mcus/boards > > > have support for peripherals that are present in other similar MCUs > > > but not other mcus/boards, that ends up some mcus boards have paertial > > > support for some different peripherals or even the same peripherals > > > but in a different way. I know that code duplication is by design not > > > to crash many things at once, but maybe there is a way to re-use some > > > code among mcus/boards and so improve coherence? :-) > > > > > > Thanks :-) > > > Tomek > > > > > > > > > > > > > > > On Mon, Jun 9, 2025 at 10:43 PM Alan C. Assis <acas...@gmail.com> > wrote: > > > > > > > > Hi Everyone, > > > > > > > > To implement the item 11 of the actions to improve NuttX: > > > > https://github.com/apache/nuttx/issues/16278 I requested ChatGPT to > list > > > > the most common signals/interfaces existent on NuttX: > > > > https://chatgpt.com/share/6841d483-5400-8012-ada6-b962d215f410 > > > > > > > > So I created a project to Document and later implement this board: > > > > > > > > https://github.com/acassis/nuttx_board_std > > > > > > > > But before carrying on with the implementation I think it is > important to > > > > discuss with everybody here which features (peripherals) we need to > have > > > on > > > > the baseboard. The MCU module is supposed to have only the MCU, > > > capacitors, > > > > crystal(s) and the connector to plug in the baseboard. > > > > > > > > I created a channel on Discord called #nuttx_standard_board to avoid > > > > polluting this mailing list. > > > > > > > > Best Regards, > > > > > > > > Alan > > > > > > > > > > > > -- > > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info > > > > > > > -- > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info >
