Update - Summer 16

A project log for Moti, a smart servo

Moti is a smart servo that simplifies the design of intricate robots.

Nicholas StedmanNicholas Stedman 06/25/2016 at 19:010 Comments

I haven't posted an update in a long time, and people suspect that the project is dead. Actually, it isn't. I got busy at my job for most of 2015. But things died down a bit this year, and so I've been pushing ahead on the project, revising both the circuit and firmware.

What's changed? Most significantly, I switched from using the atmega328 to using samd21 (ARM cortex m0+). This allowed me to resolve a bunch of nagging problems. For one, now you can program the servo directly over USB, rather than having to purchase an FTDI dongle. Secondly, I was running out of flash space and RAM on the 328, and so now there's 8 times more of each, as well as 3 x speed jump, and 32 bit instruction. Thirdly, because of the performance gains Moti can now effectively make use of an RTOS to schedule events, which makes it easier to program because many tasks automatically happen in the background. Fourthly, The magnetic encoder has also been redesigned so that board is integrated into a case. I hope to sell these soon enough as their own thing for anyone looking for 360 degree sensing.

In the following video I go over these topics, plus demonstrate some of the performance characteristics of project. Let me know your thoughts.