Hardware Reference
In-Depth Information
246 Start: word = 0;
247 count = 0;
248
249 /
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250
Wait for a space of 46 ms :
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251
/
252 do {
253 v = wait_change(&ms);
254 } while ( ms < 46.5 );
255
256 /
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257
Wait for start : 4.5ms high, then 4.5ms low :
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258
/
259 for ( v=1;; ) {
260 if ( v )
261 v = wait_level(0);
262 v = wait_level(1);
263 v = wait_change(&ms); /
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High to Low
/
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264 if ( !v && ms >= 4.0 && ms <= 5.0 ) {
265 v = wait_change(&ms);
266 if ( v && ms >= 4.0 && ms <= 5.0 )
267 break ;
268 }
269 }
270
271 /
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272
Get 32 bi t code :
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273
/
274 do {
275 /
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Wait for line to go low
/
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276 v = wait_change(&ms);
277 if ( v || ms < 0.350 || ms > 0.8500 )
278 goto Start;
279
280 /
Wait for line to go high
/
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281 v = wait_change(&ms);
282 if ( !v || ms < 0.350 || ms > 2.0 )
283 goto Start;
284
285 b = ms < 1.000 ? 0 : 1;
286 word = (word << 1) | b;
287 } while ( ++count < 32 );
288
289 /
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290
Eliminate key stutter :
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291
/
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