What it will do
Serial bus servos such as the ST3215 talk half-duplex TTL serial on a shared line, with every servo on the bus given its own ID. That is a good protocol for servos and an awkward one to add to a robot whose sensors already live on I²C. Kookabus-02 does the translation: your controller writes positions and reads feedback over the Kookabus connector, and the board drives the servo bus and supplies servo power.
The ST3215 is a 12 V bus servo with a 360° magnetic encoder and position, speed, load and temperature feedback. Servos that speak the same Feetech-style protocol should work in the same way.
Planned specifications
These are the design targets. They will be replaced with measured figures when the board ships.
| Servo ports | 4, each a 3-pin servo bus header |
|---|---|
| Servo types | ST3215 and compatible Feetech-protocol serial bus servos |
| Servo bus | Half-duplex TTL serial, 1 Mbps |
| Servo power input | 6 to 12.6 V, matching the ST3215 supply range. Sized for a 3S pack or the LOAD output of a Kookabus-01 through a regulator. |
| Control interface | I²C over the standard Kookabus 4-pin connector, 2 connectors for chaining |
| Address | Selectable with solder jumpers A0 and A1 |
| Feedback | Position, speed, load, voltage and temperature per servo, readable over I²C |
| Other | Servo ID assignment and bus scan without a separate programmer |
Meanwhile
- Kookabus-01 is available now. Its site has the connector and addressing scheme every Kookabus board shares. Read the Kookabus-01 site.
- Building with ST3215 today? Design your servo power around 12 V and 3-pin bus headers, and Kookabus-02 will drop in later.