New more simple code for lacquey-fetch adapted to the new firmware

[rsantos88]

Only one byte to send the order of the hand movement. Hand values sended to mbed:

• 0 loose hand
• 1 open hand
• -1 close hand

[coveralls]

Coverage remained the same at ?% when pulling a101bc52e883dd4f84788212b6104dc28b0e6d4e on mbed-lacquey-fetch into 0b4aaafca4da7bee67bc3b8be26cb2dec7da5aab on develop.

[jgvictores]

There was a reason for sending more than 3 different values: being able to control the grip torque.

Obviating that fact (it has passive compliance anyway), some of the minimum requirements would be the following:

• [ ] It seems the following line could be reduced to uint8_t msg_position_target[]= {0x00} (remove comment on 8 bytes): https://github.com/roboticslab-uc3m/yarp-devices/blob/a101bc52e883dd4f84788212b6104dc28b0e6d4e/libraries/YarpPlugins/LacqueyFetch/IPositionControl2RawImpl.cpp#L36
• [ ] Move https://os.mbed.com/users/raulsr988/code/LacqueyFetch/file/3b3e8f8352a8/main.cpp to https://github.com/roboticslab-uc3m/yarp-devices/tree/develop/firmware/LacqueyFetch
• [ ] Are the other two files in https://os.mbed.com/users/raulsr988/code/LacqueyFetch required?
• [ ] Document the mbed firmware registering/compiling/downloading/uploading process in https://github.com/roboticslab-uc3m/yarp-devices/blob/develop/firmware/LacqueyFetch/README.md
• [x] Change -1 to 2 and use unsigned chars (only 8-bit assured by C) on both ends. ((see comment on legacy protocol, below))

[rsantos88]

In views of the legacy-PIC code, protocol will be:

0xA0 -> Mantener abriendo
0xC0 -> Mantener cerrando
0xF0 -> Parar (dejar de actuar, enable a 0)

[rsantos88]

Now, the mbed firmware of lacqueyFetch is compatible with the code of the old hand PIC. Therefore, tt's not necessary to do this PR. See the changes here: https://os.mbed.com/users/raulsr988/code/LacqueyFetch/rev/8ebb11ba21be/ It works fine.

[jgvictores]

Okay, perfect! Thanks, closing!!