Project Logs

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• Putting it all together

  Samuk • 10/05/2022 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.

  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

  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

  Samuk • 09/19/2022 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: https://github.com/rosmo-robot/micro-bot/tree/master/Hardware/V3

  
  See how that fits together with our BLDC chassis here: https://rosmo.io/
  

• Parts are hard

  Samuk • 09/11/2022 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

  Samuk • 06/28/2022 at 13:48 • 0 comments

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

  
  The encoders fit now too

• More bodywork

  Samuk • 05/19/2022 at 23:30 • 0 comments

  More 3D work happening.

  Got a WebUI installed too, it doesn't yet do anything.
  

• Time for some software

  Samuk • 05/17/2022 at 12:07 • 0 comments

  For the first time we got all the major components of Rosmo together and plugged them in.

  Various packages are in transit to Italy, Austria, Japan and Brazil so our early adopters can get their hands on them.
  

  We probably need to do some cases.. (and use shorter headers!)

  More photos on Twitter
  

• Rosmo V2

  Samuk • 05/17/2022 at 11:32 • 0 comments

  So we decided to do a re-design of the body. This time we reached out to the FreeCAD community and built it in Freecad.

  f

  It's almost there, just a few further tweaks.  The files are available in our Github repo
  

• AS5048A Encoder Board available on Tindie $15.00

  Samuk • 05/04/2022 at 21:01 • 0 comments

  The encoders we needed for this project weren't available, so Richard made some:

  Ideal for small robots and motor control applications, this small sensor board measures the orientation of a nearby magnet (contactless measurement). It uses an SPI interface for communications, and can return angle values to 14bit precision – that’s 16384 counts per revolution, or 0.022° degrees.

  Its tiny 21mm x 17mm dimensions mean it will fit any project, and can be easily mounted even to tiny motors or actuators using the 2.2mm holes.

  They are now available on Tindie
  

• Ottocore v2.1 getting made

  Samuk • 05/04/2022 at 20:55 • 0 comments

  So following on from the Opencore 1.0 board

  The Octocore boards have been made!
  

• Motors move

  Samuk • 03/09/2022 at 13:21 • 0 comments

  Motors move for the first time

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