Some more detail on the programming protocol for the HFP-10 and the HS-5475HB Servo Protocol.

To start the serial communication, power up the servo, respond to the first "+" with a "+" in reply. After a couple of seconds you get another "+", and then you can use the commands. Comands are ignored till then.

Commands are acked with a "++", or a response. bad checksum are nacked with a "-" and communication ceases and must be restarted.

The "a" and "b" commands appear to read and write to eeprom respectively.

Not really sure about the "d" commands. The "e" and "f" are used during endpoint programming.

The address space seems to have two similar tables from 0 to 0x1C and 0x30 to 0x4C. maybe this is an alternate parameter set, but the HFP10 (mine is version 1.02) does not seem to modify the second set.

The set direction command writes to addresses 0x13, 0x14,0x19, 0x1a, 0x1b, and 0x1c, though only 0x1b changes value as 0 or 1.

The set speed write to locations 06 and 0x1c, where 06 is the speed and for the 5475 servo 0x1c is (0xfa-speed). for the 5245 servo the location 0x1c is different.

I will gather some more information. And also to change some settings. It would be useful to see the values for other servos of same and different model.

The value written to location 0x1C changes for the direction change too. This seems to be because the location 0x1c is the checksum of the contents of the locations 0 through 0x1b. So this location is always changed.

This probably explains why the whole parameter set is read for even a small change, since it recalculates the checksum

Sounds like you are making some good progress Richard!

And deffinately needed a new thread.

The checksum location for all settings is an interesting way of doing things, also the fact that setting locations are different for various servos is kind of odd. I can only assume they do not all use the same micro, and so memeory ranges are different?

M@