Missing a white line detection case

[poupryc]

Four cases must be managed by this function (which should perhaps be renamed).

• no white line is detected
• the right sensor detects a white line
• the left sensor detects a white line
• both sensors detects a white line

the last case seems to be forgotten

PS: maybe add an enum to make the return values clearer

sumobot-code/code/basic/sumobot.ino

Lines 364 to 374 in 11e8458

	int ligneBlanche()
	{
	// si le capteur de ligne blanche avant gauche ou droit est activé
	if (analogRead(TCRT_G) <= SEUIL_GAUCHE) {
	return AV_GAUCHE;
	} else if (analogRead(TCRT_D) <= SEUIL_DROIT) {
	return AV_DROIT;
	} else {
	return 0;
	}
	}