Skip to main content

Can sysfs gpio descriptors stay open as long as wrapper class lives?

I'm trying to write a basic wrapper gpio class that will handle read and write to gpio pins in a nvidia jetson, using linux sysfs interface, with python. I want to keep /sys/class/gpio/gpioXXX/value open as a file to avoid repeating file open/close using with open(...) as f approach. The reason for my approach is that I will keep changing the value in my process (to toggle a LED on-off) regularly. I'm thinking of closing it once the wrapper class gets deleted. The thing is that I know that opening files without close counterparts can cause resources leaks and that makes me anxious.

class GPIOWrapper:
    def __init__(self):
        self.fd = open("/sys/class/gpio/gpioXXX/valu","w+") 

    def set(self,val):
        self.fd.write(str(val)): # 0  or 1
        self.fd.flush()

    def read(self):
        return self.fd.read()

    def __del__(self): 
        self.fd.close()

What I'm asking is if the above approach valid? Or is it risky and I should stick with:

class GPIOWrapper:

    def set(self,val):
        with open("/sys/class/gpio/gpioXXX/value","w")) as fd:
            fd.write(str(val)): # 0  or 1

Furthermore, can there be side effects of keeping a file descriptor open to gpio pins indefinitely? I can't think of any but I'm new to programming peripherals. My aim is to keep this class general for any device that could use gpio in future (not just LEDs).
Thank you for your attention and help.



source https://stackoverflow.com/questions/69397609/can-sysfs-gpio-descriptors-stay-open-as-long-as-wrapper-class-lives

Comments

Popular posts from this blog

Why is my reports service not connecting?

I am trying to pull some data from a Postgres database using Node.js and node-postures but I can't figure out why my service isn't connecting. my routes/index.js file: const express = require('express'); const router = express.Router(); const ordersCountController = require('../controllers/ordersCountController'); const ordersController = require('../controllers/ordersController'); const weeklyReportsController = require('../controllers/weeklyReportsController'); router.get('/orders_count', ordersCountController); router.get('/orders', ordersController); router.get('/weekly_reports', weeklyReportsController); module.exports = router; My controllers/weeklyReportsController.js file: const weeklyReportsService = require('../services/weeklyReportsService'); const weeklyReportsController = async (req, res) => { try { const data = await weeklyReportsService; res.json({data}) console...

How to show number of registered users in Laravel based on usertype?

i'm trying to display data from the database in the admin dashboard i used this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count(); echo $users; ?> and i have successfully get the correct data from the database but what if i want to display a specific data for example in this user table there is "usertype" that specify if the user is normal user or admin i want to user the same code above but to display a specific usertype i tried this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count()->WHERE usertype =admin; echo $users; ?> but it didn't work, what am i doing wrong? source https://stackoverflow.com/questions/68199726/how-to-show-number-of-registered-users-in-laravel-based-on-usertype

The number of nodes and edges I calculated manually and by a method provided by networkx library dont match

I am trying to analyse a graph using networkx library in Python. I have implemented a function that returns the nodes and edges of that graph. After that I counted the number of nodes and edges by implementing the len() function for nodes and edges, which gave me 17 for both nodes and edges. However, when I used the method graph.number_of_nodes() of networkx library it gave me 53. My code: import pandas as pd import networkx as nx import matplotlib.pyplot as plt header_list = ["a","b","w"] E =pd.read_csv("aves-barn-swallow-contact-network.edges",sep=" ",header= None,names=header_list) # print(E.head()) # prints first few rows of the csv file G = nx.from_pandas_edgelist(E,"a","b",["w"]) nx.draw(G) plt.show() class GraphAnalyse: #finding nodes and edges def nodeEdge(self,Graph): nodes = Graph.nodes() edges = Graph.edges() ...