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+/* usdist.c */
+/* io - Input & Output with Artificial Intelligence (ai) support on AVR. {{{
+ *
+ * Copyright (C) 2010 Nicolas Schodet
+ *
+ * APBTeam:
+ * Web: http://apbteam.org/
+ * Email: team AT apbteam DOT org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * }}} */
+#include "common.h"
+#include "usdist.h"
+
+#include "modules/adc/adc.h"
+#include "modules/utils/utils.h"
+#include "io.h"
+
+uint16_t usdist_mm[USDIST_NB];
+
+void
+usdist_init (void)
+{
+ adc_init ();
+}
+
+void
+usdist_update (void)
+{
+ uint8_t i;
+ /* Simple algorithm, just make a conversion for every sensor. This should
+ * be improved because it takes too long. */
+ for (i = 0; i < USDIST_NB; i++)
+ {
+ adc_start (i);
+ while (!adc_checkf ())
+ ;
+ uint16_t v = adc_read ();
+ /* Our sensors return a value between 1 and 5 V proportional to the
+ * distance between calibrated values. */
+ if (v <= 1024 / 5)
+ usdist_mm[i] = USDIST_MM_MIN;
+ else
+ usdist_mm[i] = USDIST_MM_MIN
+ + (uint32_t) (v - 1024 / 5) * (USDIST_MM_MAX - USDIST_MM_MIN)
+ / (4 * 1024 / 5);
+ if (usdist_mm[i] >= USDIST_MM_TOO_FAR)
+ usdist_mm[i] = 0xffff;
+ }
+}
+