Raspberry Pi Forums

paddyg

From your description of what you want to happen I would have thought the loop should record the times that objects pass each sensor and the logic count accordingly i.e if tm1 > tm2 and (tm1 - tm2) < MAXTM: count += 1 elif tm2 > tm1 and (tm2 - tm1) < MAXTM: count -= 1 You also need to take into acco...

paddyg

Also your code has lots of repetition in it which is a good indication that you will find it difficult to figure out logic, debug problems etc etc. In your situation I would opt for using a 'class' to represent each door and have a list of them. I know this might be more advanced than you want to ta...

paddyg

I think Flask has to run in the main thread. If that's an issue you can put it in its own process and communicate via queue objects. I will see if I can find a github repo I once worked on which did that kind of thing. Paddy here's the link, if you can make anything of it. Feel free to ask, though i...

paddyg

I suspect nobody has replied because they are rather confused by the equation and explanation. My advice would be to do a bit of simple programming, maybe follow an introduction to python course. Most programming languages will do arithmetic operations in approximately BODMAS order so in your exampl...

paddyg

John, sounds like progress of some kind. Does it work ok if you comment out all the gpio stuff and just use the tk buttons? Try to add code back in a bit at time to narrow down the point where it stops working.
Paddy

paddyg

That's odd. I can't reproduce that error but I do get errors further on. Essentially a) the functions need to be defined before allocating to buttons (obviously!!) b) when_pressed is used differently, basically set equal to a function. See my revised code at the bottom which I've just checked on thi...

paddyg

Hi, I've not had chance to sort this out but did have a look around last night. Using OMXPlayer (the python wrapper module) I found that I could get useful info and control when only one instance of omxplayer was instantiated but when I created a second one then they both returned the same negative ...

paddyg

busy now but will look later. I would expect you to need to use the subprocess module to run OMXPlayer twice. That's slightly trickier but not too bad

paddyg

The thing most likely to cause confusion for the python interpreter is using the same names for different things. Python will let you do this and will attempt to work out what to do but it will almost certainly confuse you! Typical issues are naming the program or imported file with a name that clas...

paddyg

You only have to wait a hundredth of a second plus whatever the response time of the mote is. You could have a toggle variable that you set with the GPIO button def LightThread(): global lights_on, lights_hide # don't need to have this line as you're not updating these but it makes it explicit while...

paddyg

Global variables usually work ok with Threads, or you can pass an object type of argument (i.e. an instance of a class or a list, but not a simple boolean) to the thread or you can use a Queue. Maybe post your code?

paddyg

Well most people will be put off by your un-formatted post. You need to use code tags (see sticky post at the top). Unless you have a very strong reason not to (and I couldn't see one in your code) you should use python3. i.e. import tkinter as tk. w.r.t your GPIO question you should, IMO, use https...

paddyg

maybe cputemp() is creating new instances of Text objects that somehow evade garbage collection (I've come across this with tk before) You should create one instance of your temerature Text and update that each loop along the lines of this example https://lawsie.github.io/guizero/blocking/

paddyg

When I've done similar things I've done the database connection at the beginning of the program when it starts so that conn and c are available to all functions (the alternative would be to make them 'belong' to your UI class and create them when you set it up (so they would be self.conn and self.c)...

paddyg

Well spotted. I just used code that you posted but you just posted some code from Matt Richardson that you didn't understand! Hopefully you've learned something in the process.

paddyg

Well google (or other search engine) 'should I connect 5V to raspberry pi gpio, even through a resistor' and see what other people think. Strange that your system doesn't work, it works fine for me as you can see on the video, and also when I put in the pull_up_down argument in and touched pin12 the...

paddyg

Hmm 5V sounds a lot!!

The best way is to use internal pull up like you do in some of your code snippets and keep even 3V3 away.

paddyg

Did yo check program on your system ? Fair cop, I just assumed that if the GPIO stuff worked ok for you then my code would probably be ok too. So I quickly copied the code to my Raspberry Pi to test it. Surprise, surprise it works fine! https://youtu.be/YQvqGKlydx0 EDIT - kids, don't do what I'm do...

paddyg

Really you should heed our earlier advice and get comfortable with simpler programming concepts before becoming too confused with this kind of thing but here is a minimalist web page that polls another web page every 1000ms. The other web page runs your GPIO checking. There are various javascript li...

paddyg

When you say 'press the push button' I assume (having read and understood @topguy's explanation above) that you mean 'press the push button and hold it down while I refresh the page'. In which case it's not clear why it's not working. I would put in print() statements a various places to try to trac...

paddyg

presumably http://192.168.0.101:5000/readPin12

paddyg

What url are you typing into the browser? When you say 'refresh' it sounds like you are just reloading main.html. If you want the pin status on the main page you will (obviously) have to put the gpio reading code into that function (hello()). Otherwise you will have to enter the route to readPin12()...

paddyg

Well, if you don't want a variable pin number then it's not a 'variable'. Most (all) languages can't cope with variables named '12'. At this point I should say that if you are just getting into programming then learning to make interactive web pages is a bad place to start. A sound investment on you...

paddyg

he uses a system now pretty universal with dynamic Web apps where routing to different 'pages' and arguments are passed in the url. In the example you posted putting pin in angle brackets does the magic @app.route("/readPin/<pin>") def readPin(pin): try: means you can feed a url such as .../readPin/...

paddyg

As @topguy says, web pages aren't normally 'running' like a python loop, you have to manually refresh them to see if any changes have happened. You can put some javascript on your display page that can loop and read an information serving page but generally speaking the way web pages work takes a wh...

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