Rosmo robot

Creating modular open hardware robot components

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Modular Open Hardware robot bits.

Open-hardware robots for ROS2/ MicroRos & SimpleFOC 

A ‘grown-up toy’ micro-robot that can be assembled without soldering, with components available worldwide. For serious hobbyists, universities, R&D. Aiming at RVR niche

Modular robotics components for Brushed & BLDC motors.

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OctoCore ESP32 dev board

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OctoCore ESP32 dev board

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  • 1 × BOM: Passive Components / Misc. Passive Components

  • Pico shields - Feather, Micromod, MikroBUS

    Samuk12/01/2023 at 15:34 0 comments

    Still obsessing over a modular stackable system.

    M10cube or Ruslan's building set both start from first principles, if we design everything from scratch how does it look.

    I'm interested in a more pragmatic approach; How can we make what already exists work better together?

    I've played with the M5stack format and kicked around using the Beagleboard pinout

    Arguably the Pi Pico format is becoming a 'default' footprint for microcontroller work. It at least has the benefit of having plenty of pins.  It's a very narrow board though, not much room to play with.

    So how does it look if we stick with the pico pinout (and maybe get a bit opinionated about how it's used, but break out the width to 28mm spacing?

    The 'pico' one

    Would be used as the compatibility layer between the narrow and wide spacing.

    They could use short pins

    They would be compatible with existing open hardware pico bits

  • XRP-X4

    Samuk11/25/2023 at 00:12 0 comments

    Did a bit more playing around with

  • XRP-X4

    Samuk09/18/2023 at 18:08 0 comments

    I like the new XRP robot board from Sparkfun.

    It's developed for

    They have a nice curriculum for it

    There's a bom and a basic PCB linked from for the 4wd version

  • Simple bot

    Samuk03/21/2023 at 07:57 0 comments

    Once we have the main 'Rosmo' chassis working, We may revisit smaller cheap(er) robots

    These would again be based on the Micromod perhaps doing an ESP32 S3 micromod chip.

    The micromod would sit in a stackable carrier developed here

    On the board

    - 9v > 3v3 conversion,

    - £3 TB6612FNG motor driver 

    - Pins at front are SPI & I2C in Breakout garden format

    - Not much else

    The Escornabot code based on five buttons seems good for young kids. We could adapt their button board to the 60pin stack

    The MCU stack could be based on the Micromod:

  • Schematic complete, routing begins

    Samuk03/11/2023 at 22:07 0 comments

    Did some playing around with some 3D models

    Opened some GitHub issuesto track the changes we need to make to the existing Smartcar lib. 

  • Smartcar 2.0

    Samuk02/10/2023 at 23:28 0 comments

    Playing around with the stacking concept in a slightly larger footprint.


    Doing a brushed version first, then swapping out the motors board for a BLDC version later


  • Putting it all together

    Samuk10/05/2022 at 17:08 0 comments

    Rosmo is a project to make small openhardware robots for educational and hobbyist use. We aim to design capable robots which can be assembled without soldering. It’s a modular set of open-hardware components that can be assembled into robots of different complexity and price. It’s all based on ESP32 so should support MicroROS work.

    We value modularity. The project started working with the M5stack system. The robot you see above is the culmination of that work. We built a chassis, ESP32dev board and ESC in this 5cmx5cm profile. We learnt a lot doing this. Unfortunately the parts crisis has meant that the ESC is not obtainable until at least 2023. We continue to test and develop using the small numnber of ESC boards we have produced.

    We also identified some issues with the M5stack system, in particular the header is hard to obtain at resonable prices. We’ve therefore pivoted our work to work with the Feather footprint to give a wider array of add-on boards. Whilst the Feather is great it is very small, so we’re also working with some slightly larger daughter boards using our own pinout in 6cm x ~5-10cm.

    We have some early drafts of this work underway with the Feather:bit board the intention is to use this board in two versions of a ~10cm x ~10cm robot.

    The first variation is Rosmo:Bot which uses cheaper brushed motors. Brushed

    The pinout at the rear is for daughter boards


    The second variation will be ‘Rosmo:BLDC’ using Brushless motors. We have a chassis and plan to use it initially with a very overpowered rp2040 ESC

    ROSmo BLDC

    The idea is the Rosmo:Bit PCB can be ‘upgraded’ by removing the wheels and attaching it to this chassis. It will provide mounting for the Microcontroller, sensors. In time we hope to use or develop smaller and cheaper SimpleFOC driver boards that are more suitable for this small robot.

    Software wise our intention is to run MicroROS/ROS2 on both the Rosmo:bot and Rosmo:BLDC. Initial work has started using Linorobot2. We’re waiting on a couple of upstream bugs to be fixed before this can progress.

    We’re also interested in supporting Smartcar_shield firmware on Rosmo:bot

  • Brushed motor board

    Samuk09/19/2022 at 20:19 0 comments

    This project is primarily about BLDC (brushless) motors.

    Since our ESC cannot be made at the moment (parts crisis) we've been playing around with a brushed version too

    Files are here:

    See how that fits together with our BLDC chassis here:

  • Parts are hard

    Samuk09/11/2022 at 20:27 0 comments

    So the parts for our ESC are unavailable

    Until we can get more we're going to play with an overpowered Pi2040 based board.

    Done a new chassis for it, waiting on some bits to arrive

  • More model tweaks

    Samuk06/28/2022 at 13:48 0 comments

    So I think we've finally got the body fitting correctly

    The encoders fit now too

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