1 // Copyright 2024 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 15 #include "pw_digital_io/polarity.h" 16 #include "pw_digital_io_linux/digital_io.h" 17 #include "pw_log/log.h" 18 #include "pw_status/try.h" 19 20 using pw::digital_io::LinuxDigitalIoChip; 21 using pw::digital_io::LinuxInputConfig; 22 using pw::digital_io::Polarity; 23 using pw::digital_io::State; 24 InputExample()25pw::Status InputExample() { 26 // Open handle to chip. 27 PW_TRY_ASSIGN(auto chip, LinuxDigitalIoChip::Open("/dev/gpiochip0")); 28 29 // Configure input line. 30 LinuxInputConfig config( 31 /* gpio_index= */ 5, 32 /* gpio_polarity= */ Polarity::kActiveHigh); 33 PW_TRY_ASSIGN(auto input, chip.GetInputLine(config)); 34 PW_TRY(input.Enable()); 35 36 // Get the input pin state. 37 PW_TRY_ASSIGN(State pin_state, input.GetState()); 38 PW_LOG_DEBUG("Pin state: %s", 39 pin_state == State::kActive ? "active" : "inactive"); 40 41 return pw::OkStatus(); 42 } 43