1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/bash/gpio.sh Sat Nov 05 17:32:57 2016 +0100
1.3 @@ -0,0 +1,108 @@
1.4 +#!/bin/bash
1.5 +
1.6 +# GPIO.sh
1.7 +# Copyright © 2016 František Kučera (frantovo.cz)
1.8 +#
1.9 +# This program is free software: you can redistribute it and/or modify
1.10 +# it under the terms of the GNU General Public License as published by
1.11 +# the Free Software Foundation, either version 3 of the License, or
1.12 +# (at your option) any later version.
1.13 +#
1.14 +# This program is distributed in the hope that it will be useful,
1.15 +# but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 +# GNU General Public License for more details.
1.18 +#
1.19 +# You should have received a copy of the GNU General Public License
1.20 +# along with this program. If not, see <http://www.gnu.org/licenses/>.
1.21 +
1.22 +# GPIO.sh is a set of functions for controlling GPIO pins of Raspberry Pi or similar computer
1.23 +
1.24 +_gpio_valid_port() {
1.25 + case $1 in 0|1|4|7|8|9|10|11|14|15|17|18|21|22|23|24|25)
1.26 + return 0;;
1.27 + *)
1.28 + return 1;;
1.29 + esac
1.30 +}
1.31 +
1.32 +# export -f _gpio_valid_port
1.33 +# seq 0 30 | xargs -n1 bash -c 'printf "%4s" "$0: "; _gpio_valid_port $0 ; if [ $? -eq 0 ]; then echo "valid port number"; else echo; fi'
1.34 +
1.35 +
1.36 +_gpio_log_error() {
1.37 + # TODO: $(date --rfc-3339=seconds) or ● ?
1.38 + echo -e "\e[1;31m$1\e[0m"; > /dev/stderr;
1.39 +}
1.40 +
1.41 +_gpio_log_warning() {
1.42 + echo -e "\e[2;33m$1 \e[0m"; > /dev/stderr;
1.43 +}
1.44 +
1.45 +
1.46 +# open (export) the port and set its direction
1.47 +# parameters:
1.48 +# port number
1.49 +# direction: in/out
1.50 +gpio_open() {
1.51 + local port="$1";
1.52 + local direction="$2";
1.53 + if [ $# -ne 2 ] || [[ "$direction" != @("in"|"out") ]]; then _gpio_log_error "usage: ${FUNCNAME[0]} <port> <in|out>"; return 1; fi
1.54 + if ! _gpio_valid_port "$port"; then _gpio_log_error "invalid port number: $port"; return 1; fi;
1.55 +
1.56 + if [ -d "/sys/class/gpio/gpio$port" ]; then
1.57 + _gpio_log_warning "port $port is already exported → will just set direction: $direction";
1.58 + else
1.59 + echo "$port" > "/sys/class/gpio/export" || return 1;
1.60 + fi;
1.61 +
1.62 + echo "$direction" > "/sys/class/gpio/gpio$1/direction";
1.63 +}
1.64 +
1.65 +
1.66 +# close (unexport) the port and set its direction
1.67 +# parameters:
1.68 +# port number
1.69 +gpio_close() {
1.70 + local port="$1";
1.71 + if [ $# -ne 1 ]; then _gpio_log_error "usage: ${FUNCNAME[0]} <port>"; return 1; fi
1.72 + if ! _gpio_valid_port "$port"; then _gpio_log_error "invalid port number: $port"; return 1; fi;
1.73 +
1.74 + if [ -d "/sys/class/gpio/gpio$port" ]; then
1.75 + echo "$port" > "/sys/class/gpio/unexport";
1.76 + else
1.77 + _gpio_log_error "port $port is not open";
1.78 + return 1;
1.79 + fi;
1.80 +}
1.81 +
1.82 +# reads value of given port
1.83 +# parameters:
1.84 +# port number
1.85 +gpio_read() {
1.86 + local port="$1";
1.87 + if [ $# -ne 1 ]; then _gpio_log_error "usage: ${FUNCNAME[0]} <port>"; return 1; fi
1.88 + if ! _gpio_valid_port "$port"; then _gpio_log_error "invalid port number: $port"; return 1; fi;
1.89 +
1.90 + if ! cat "/sys/class/gpio/gpio$port/value"; then
1.91 + _gpio_log_error "unable to read value of port $port";
1.92 + return 1;
1.93 + fi
1.94 +}
1.95 +
1.96 +# writes the value to given port
1.97 +# parameters:
1.98 +# port number
1.99 +# value: 0/1
1.100 +gpio_write() {
1.101 + local port="$1";
1.102 + local value="$2";
1.103 + if [ $# -ne 2 ] || [[ "$value" != @("0"|"1") ]]; then _gpio_log_error "usage: ${FUNCNAME[0]} <port> <0|1>"; return 1; fi
1.104 + if ! _gpio_valid_port "$port"; then _gpio_log_error "invalid port number: $port"; return 1; fi;
1.105 +
1.106 + if ! echo "$value" > "/sys/class/gpio/gpio$port/value"; then
1.107 + _gpio_log_error "unable to write value $value to port $port";
1.108 + return 1;
1.109 + fi
1.110 +}
1.111 +