// ucoolib - Microcontroller object oriented library. {{{ // // Copyright (C) 2013 Nicolas Schodet // // Permission is hereby granted, free of charge, to any person obtaining a // copy of this software and associated documentation files (the "Software"), // to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, // and/or sell copies of the Software, and to permit persons to whom the // Software is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER // DEALINGS IN THE SOFTWARE. // // }}} #include "usdist.hh" namespace ucoo { UsDist::UsDist (UsDistControl &ctrl, Adc &adc, Io &io, int distance_min, int distance_max, int distance_too_far, int resolution) : adc_ (adc), io_ (io), next_ (0), distance_min_ (distance_min), distance_max_ (distance_max), distance_too_far_ (distance_too_far), resolution_ (resolution), distance_ (-1) { next_ = ctrl.sensors_; ctrl.sensors_ = this; if (resolution_ == -1) resolution_ = adc_.get_resolution (); } void UsDist::enable () { io_.set (); } void UsDist::disable () { io_.reset (); } int UsDist::read () { int v = adc_.read (); // The sensor returns a value between 4 and 20 mA proportional to the // distance between calibrated values. Ignore faulty sensors. const int max = resolution_; const int min = max / 5; if (v <= min / 4) distance_ = -1; else if (v <= min) distance_ = distance_min_; else distance_ = distance_min_ + ((v - min) * (distance_max_ - distance_min_) / (max - min)); if (distance_too_far_ != -1 && distance_ > distance_too_far_) distance_ = -1; return distance_; } UsDistControl::UsDistControl (int period) : period_ (period), sensors_ (0), current_ (0), wait_ (0) { } bool UsDistControl::update () { bool new_measure = false; if (wait_) wait_--; else { if (current_) { current_->disable (); current_->read (); new_measure = true; current_ = current_->next_; } if (!current_) current_ = sensors_; current_->enable (); wait_ = period_ - 1; } return new_measure; } } // namespace ucoo