Servos not serving

[Tabsoft]

Alain,

I guess I'm missing something in your "Pause Refresh - Pulse - Pulse - Pulse" statement.
The "Pause" amount for loop # 1 will be "20 - 240 - 240 - 240 = 68ms"
For loop #2 it will be "20 - 239 - 239 - 239 = 71ms"

So to turn 90deg it will take 15.16 seconds?
Is this right?

Total Pause (ms):	   15.16
Total Pause(Value): 15160

Pulse	Pause 
Value Value
----- -----
240	68
239	71
238	74
237	77
236	80
235	83
234	86
233	89
232	92
231	95
230	98
229	101
228	104
227	107
226	110
225	113
224	116
223	119
222	122
221	125
220	128
219	131
218	134
217	137
216	140
215	143
214	146
213	149
212	152
211	155
210	158
209	161
208	164
207	167
206	170
205	173
204	176
203	179
202	182
201	185
200	188
199	191
198	194
197	197
196	200
195	203
194	206
193	209
192	212
191	215
190	218
189	221
188	224
187	227
186	230
185	233
184	236
183	239
182	242
181	245
180	248
179	251
178	254
177	1
176	4
175	7
174	10
173	13
172	16
171	19
170	22
169	25
168	28
167	31
166	34
165	37
164	40
163	43
162	46
161	49
160	52
159	55
158	58
157	61
156	64
155	67
154	70
153	73
152	76
151	79
150	82
149	85
148	88
147	91
146	94
145	97
144	100
143	103
142	106
141	109
140	112
139	115
138	118
137	121
136	124
135	127
134	130
133	133
132	136
131	139
130	142
129	145
128	148
127	151
126	154
125	157
124	160
123	163
122	166
121	169
120	172

[Acetronics2]

Alain,

I guess I'm missing something in your "Pause Refresh - Pulse - Pulse - Pulse" statement.

you're right ! I missed time scaling

should be

Pause Refresh - ((pulse + pulse + pulse)/100)

note Refresh could simply be 15ms ( as precise 50 Hz repeating signal is not compulsory - only the 1.2 - 2.4 ms "1" level - )

your travel time will simply be ...

(240-120)* 20ms = 2.4 seconds ...

[queenidog]

Just wanted to say thanks to all for your insightful comments and programming hints. I printed off the stuff for later perusal and comparison to my program. I'm a "minimalist", I program with the least amount of code required (thus don't always initialize) and even build circuits with low parts counts. That's where I get into trouble...

Thanks again.

[Tabsoft]

If you want the duty cycle to be as close to 50Hz you can do this to account for the Pulsout statements, Low xx statements, For/next logic and the Pause statement.

Change the Refresh constant value to 20000 'microseconds

Then use this for the pause.

Pauseus Refresh - (((pulse + pulse) + (pulse / 3)) * 10)

This should keep the total duty cycle time to 20ms +/- (~100) microseconds.

[Dave]

Queenidog, Here is a program I wrote some time ago for a couple of kids to test some servos for there robot in the FIRST competition. It is a minimalist program I wrote during lunch one day. It might help. Oh I forgot, Also attached is a schematic I updated a couple of years ago. Enjoy...