Partie interactive du site pédagogique ELECINF344/ELECINF381 de Télécom ParisTech (occurrence 2011).


[CASPER] Remote control on Casper

Today, we made some improvements in the way casper moves. Now, it will reach a specified target (direction + bending) passing by every intermediary position, preventing casper from brutal moves… Moreover, we added a way of specifying the movement’s speed.

Besides, now we can control Casper remotely. We are currently using a Zigbee module but eventually it will be controlled by a wired UART connexion with the BeagleBoard. We specified the following protocol :

Command format :

x represents a number
A command can’t exceed 10 chars

S : start
E : end
A : absolute command indicator
R : relative command indicator
X : special command indicator

Absolute command :

xxx.xx : direction xxx (0 to 360) – bending xx (0 to 90)

Example :       > SA145-90E
Casper moves to direction 145°, bending 90°

Relative command :


Exemples :      > SR+300-10E
Casper’s direction increases by 300° and bending decreases by 10°

Special commands :
0 : YES
1 : NO
2 : 180°
3 : 360°

Example : > SX0E : Casper says mechanically yes.

Tomorrow, we will add speed management to these commands.