+void ramp_up(unsigned char channels)
+{
+ unsigned char step = 0;
+
+ do {
+ pwm_set(channels, step++);
+ delay();
+ } while (step != 0);
+}
+
+void ramp_down(unsigned char channels)
+{
+ unsigned char step = 255;
+
+ do {
+ pwm_set(channels, step--);
+ delay();
+ } while (step != 255);
+}
+
+void ramp_up_down(unsigned char channels)
+{
+ ramp_up(channels);
+ ramp_down(channels);
+}
+