Hitec Multi-protocol Interface spec?
Hitec Multi-protocol Interface spec?
by subpilot
Mon Mar 06, 2006 6:39 am
Anybody know where I can get the spec for the Hitec HMI (Multi-protocol Interface )?
by bauermech
Mon Mar 06, 2006 4:08 pm
This just touches on the subject... I'll try and dig deeper later on...
http://www.robonova.de/store/down/downl ... g_8498.pdf
http://www.robonova.de/store/down/downl ... g_8498.pdf
by limor
Wed Nov 15, 2006 2:29 am
I wanted to share some new info about the RN1's mysterious HMI interface. Remember that the 8498 supports two types of protocols. One is a RC compatible PWM with some extra position feedback when sending a short pulse (see the FAQ). The second is a serial interface called Hitec Multi-protocol Interface.
This protocol alegedly supports RS232 when connected to a PC using the yet-unavailable PC serial interface. According to Hitec the HMI allows for:
- Firmware upgrade
- Setting of the servo's holding-position Compliance function parameters (gain, deadband etc.)
In addition Hitec mentions the possibility of linking 128 servos in Daisy-chain (probably RS485 interface like the Bioloid) and being able to serially communicate with each servo and get voltage, current and position of each servo. Some reverse engineering of this was attempted by Ibbotson.
If Hitec kindly exposed this information, it would transform the 8498 servo into a very attractive control research tool (like the competing Robotis servos), allowing advanced hobbyists and researchers to device their own feedback control techniques rather than only rely on goto-position-and-hold sequences.
Good news is that I have another piece of the puzzle - some information about the serial protocol. Check it out: http://robosavvy.com/Builders/limor/HMI_Info.html
This protocol alegedly supports RS232 when connected to a PC using the yet-unavailable PC serial interface. According to Hitec the HMI allows for:
- Firmware upgrade
- Setting of the servo's holding-position Compliance function parameters (gain, deadband etc.)
In addition Hitec mentions the possibility of linking 128 servos in Daisy-chain (probably RS485 interface like the Bioloid) and being able to serially communicate with each servo and get voltage, current and position of each servo. Some reverse engineering of this was attempted by Ibbotson.
If Hitec kindly exposed this information, it would transform the 8498 servo into a very attractive control research tool (like the competing Robotis servos), allowing advanced hobbyists and researchers to device their own feedback control techniques rather than only rely on goto-position-and-hold sequences.
Good news is that I have another piece of the puzzle - some information about the serial protocol. Check it out: http://robosavvy.com/Builders/limor/HMI_Info.html
by beermat
Wed Nov 15, 2006 5:09 am
HMI has always puzzled me, although I never looked into it. So, is the story that although they say it is there, there is nothing out there that uses HMI in any way? The whole daisy chaining aspect, for instance - that's useful and powerful, but after all this time, none of the aspects of HMI are in use in any form?
