This forum seemed somewhat deserted. But I'm posting this here as it seemed relevant still and I'm hoping to get some mindshare about this:
These days there are large number of 32 bit 'development boards' e.g. mostly ARM based STM32 and various NXP and some from Atmel. TI, and not to miss out Raspberry Pico etc.
You could find examples of stm32 boards here
[
stm32-base.org]
You can find various of these boards from say marketplaces like Aliexpress, Amazon, Ebay etc. Then there are others like those (micro)python boards running STM32, ST itself offers various 'Nucleos' and 'Discovery' boards. Offerings from Olimex [
www.olimex.com], [
www.olimex.com], maybe others from Adafruit, Sparkfun etc
The good thing about them is that most of them are Arm Cortex-M based microcontrollers and there are already a large base of existing support for those mcus e.g. in Marlin etc.
One common thing about all these 'development boards' is most (about all) of them *do not share a same pinouts nor physical layouts* (even for the same MCU).
This pretty much invalidates the concept of 'shields', and the replacing concept is *connecting cables* (e.g. 'dupont' cables)
Are there any efforts to make a 'RAMPS' board, which pretty much sports the same motor control and other peripherals e.g. mosfets, temperature sensor connectors, endstops connectors, maybe these days things that could be added could include:
1) on board power supply - preferably a relatively well powered bucks converter such as LM2596 [
www.ti.com]
this on board power supply would need to provide power to the 'controller board' as well as drive other power hungry pheriperials such as a servo motor for bed tramming.
possibly needing more than 1 voltage levels as well, e.g. both 3.3v and 5v. e.g place a 'ldo' between 5v and 3.3v rail.
3) interfacing for 3.3v to 5v (or some other (higher) voltages) - this is a pain with 3.3v microcontrollers really. Nearly all of them requires a level shifter (e.g. those 74HCTxxx as level shifters) to drive 5v logic level mosfets. this prossibly needs to be better thought out as well as we'd need to be able to better adjust the Vgs operating points for the mosfets. the resistances of pcb 'heated beds' are pretty much unpredictable these days.
4) possibly add other peripherals on board that has become popular with the 'standard model' of 3d printers. e.g. servo drivers and sensors for bed tramming (auto levelling), probes such as filament run-out sensors, filament change support, fans, leds, etc.
5) one common thinking is that these days 3d printers should after all be *enclosed*, not so much for the prints, but that 3d printing has *emissions*
[
www.ncbi.nlm.nih.gov]
so it is good to think in terms of support for an enclosed environment, such as those 'tent' style enclosures. that is where led (it is often dark in the enclosure) and possibly additional temperature sensors may become relevant as well.
6) and most important, it is no longer shields but that most likely the interfacing connectors are 'dupont' pins, and connectivity between the 'RAMPS' board and 'controller' boards would be cables such as 'dupont' wires. it seemed it has become rather common that on boards it is 'male' pins, and all connecting cables using 'female' pins and shells.
RAMPS has pretty much become a 'standard model' of a 3d printer at least a 'virtual' one.
the idea is to have a *generic* board of these most commonly used peripherals on its own board so that this 'RAMPS' board can be connected to *any* development boards.
