Serial Bus Servos

[danic85]

Instead of using hobby servos for actuation I want to explore the suitability of serial bus servos.

I have ordered the following to replace the standard and micro hobby servos respectively:
https://www.waveshare.com/st3215-servo.htm
https://www.waveshare.com/product/sc09-servo.htm

I have also ordered two types of controller board:
https://www.waveshare.com/product/servo-driver-with-esp32.htm
https://www.waveshare.com/product/bus-servo-adapter-a.htm

The first board includes an ESP32 and therefore may be able to replace the arduino (with increased functionality such as wifi and bluetooth), and the second is an interface to allow UART connectivity to the servos.

Serial bus servos offer the following advantages, relevant to this project:

• Increased torque: 30kg/cm vs 6.5kg/cm for the SG5010. NOTE: 2.3kg/cm vs 3.1kg/cm for the MG92B (a slight drop)
• Position sensing: useful for feedback to detect starting position, to allow smooth movement from power-on, and also sense if they are blocked. Position, Load, Speed, Input Voltage feedback is possible on these servos.
• Serial control: rather than having multiple wires into the robot, they can be connected in a 'chain' as needed, improving modularity and making a cleaner design overall.
• 360 degree (300 for the smaller servo) rotation, ability to switch between angular and rotational movement (ST3215 only).

The goal is to completely redesign the build to allow these servos to be used in place of any hobby servos, focussing on modularity and allowing extension and modification of the design.

This, combined with the CM5 board will allow the new release to improve on the 'buddy' release significantly.

[danic85]

Initial tests will allow me to connect 3 ST3215 and 2 SC09 servos to either controller board and test suitability. The end goal would be to allow the new CM5 board to integrate with the board either via UART or bluetooth / ESP-NOW and replace all existing servos.

I'd also like to allow the 'legs' to be attached in a way that allows quick replacement for variations, so that we can vary the design easily, this is so that we can support multiple designs with the same core components.