/* 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; } }