Full-range PWM commands in Lacquey firmware

[PeterBowman]

Commit cfd8d88#diff-68eeea6c71ceb478044ee0f4dc44b6a0 (#211) adds a new PWM control layer around the LacqueyFetch device, resembling more closely its internal way of actuating the motor. However, our firmware is severely limited in that only full-positive (+100%), full-negative (-100%) and stop (0%) commands are forwarded, thus ignoring the whole [-1,1] value range (source):

yarp-devices/firmware/LacqueyFetch/main.cpp

Lines 76 to 92 in 8726fa3

	switch(data){
	case 0xA0: // open hand
	m.speed(1.0);
	break;
	case 0xC0: // close hand
	m.speed(-1.0);
	break;
	case 0xF0: // loose hand
	m.speed(0.0);
	break;
	default: // loose hand
	m.speed(0.0);
	break;
	}

Here, data is a char. Make it a 32-bit float so that it matches 38176f1.

[jgvictores]

Related:

• Promote TextilesHand to a control board device #234 (comment)
• Comment on http://www.yarp.it/SerialServoBoard_8h_source.html at Promote TextilesHand to a control board device #234 (comment)

* Not prioritary, just to point out. For starters, SerialServoBoard looks PositionControl-oriented, whereas we both agreed on exposing the more native PWM interface.

[jgvictores]

Returning to the scope of the issue, yes, I totally agree we should recover the full range at firmware level.

• This was once available in the Serial/USB setup we once had (mentioned at Promote TextilesHand to a control board device #234 (comment)).
• Obviously required at firmware level, to have this available via Canbus too.

[rsantos88]

Updated Lacquey firmware:
https://os.mbed.com/users/raulsr988/code/LacqueyFetch/rev/f31b6ddb9cd3/

[rsantos88]

Note: Currently the previus firmware is installed on the Mbed.
Waiting to install the latest changes (38176f1) in Teo to be tested completely. Right now the tests have been done under Pcanview, sending messages directly to the Mbed. All works correctly. I'll close this issue

[PeterBowman]

Just one more thing to finally mark this as closed: merge this change into firmware/LacqueyFetch/ (also update README).