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by cloudapplepi
Thu Jun 27, 2019 5:44 pm
Forum: Automation, sensing and robotics
Topic: Dashboard thermal camera (human/animal detection)?
Replies: 0
Views: 299

Dashboard thermal camera (human/animal detection)?

At the moment not (yet) planning this since I should first finish my robot project, but just wanted to gather some information and ideas for the following: Idea: A camera system (dashboard cam) used in a car to detect humans and animals in long range. Could be a either a high resolution camera or a ...
by cloudapplepi
Tue Feb 19, 2019 8:53 am
Forum: Automation, sensing and robotics
Topic: Fuse between motor driver board and power source?
Replies: 12
Views: 793

Re: Fuse between motor driver board and power source?

Fuses come in many different shapes, sizes, and materials, depending on where they're going to be used. So, here in the UK (your profile doesn't indicate where you are) plug-tops have a fuse that has to be removed from the socket before you can change it. It's got a ceramic body that won't shatter ...
by cloudapplepi
Sat Feb 16, 2019 1:28 pm
Forum: Automation, sensing and robotics
Topic: Fuse between motor driver board and power source?
Replies: 12
Views: 793

Re: Fuse between motor driver board and power source?

Why is it that rechargable batteries provide more current or in other words why do they have a lower internal resistance? You want a lesson in chemistry? Primary cells are designed to hold their charge for long periods so they don't have to be replaced too often, and the circuits they feed are gene...
by cloudapplepi
Sat Feb 16, 2019 1:23 pm
Forum: Automation, sensing and robotics
Topic: Fuse between motor driver board and power source?
Replies: 12
Views: 793

Re: Fuse between motor driver board and power source?

Thanks for the replies. Yes, I use non-rechargable batteries indeed. Why is it that rechargable batteries provide more current or in other words why do they have a lower internal resistance? Then this would also mean that I should rather use a 20A fuse when I use rechargable batteries and the 5A fu...
by cloudapplepi
Sat Feb 16, 2019 10:48 am
Forum: Automation, sensing and robotics
Topic: Fuse between motor driver board and power source?
Replies: 12
Views: 793

Re: Fuse between motor driver board and power source?

Thanks for the replies. Yes, I use non-rechargable batteries indeed. Why is it that rechargable batteries provide more current or in other words why do they have a lower internal resistance? Then this would also mean that I should rather use a 20A fuse when I use rechargable batteries and the 5A fus...
by cloudapplepi
Fri Feb 15, 2019 1:03 pm
Forum: Automation, sensing and robotics
Topic: Fuse between motor driver board and power source?
Replies: 12
Views: 793

Fuse between motor driver board and power source?

Hi (again). I'm working on a robot, based on the Devastator platform ( Link ) and I use a 7 A Dual DC motor driver board with it (this one) . In the instructions of this motor driver it says to use a 20A fuse between the board and the power source (in my case batteries; 6 x 1.5 V AA). I'm using a fu...
by cloudapplepi
Wed Feb 13, 2019 9:06 am
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

I don't know if this will help the understanding, but I'll have a go. Imagine a longish metal rod. Put one end in a flame (5V) and the other end in a bucket of ice (0V). About 2/3 of the way along that rod from the cold end it will be quite warm (3.3V). That's where you connect to it. The rod is li...
by cloudapplepi
Wed Feb 13, 2019 8:12 am
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

Well, I hope my ramblings clarified a few points for you. as one resistance alone doesn't change the 5V at all? Be careful how you interpret what I said in relation to your simple circuit. The one resistor R1 connected between Echo and PIn 18 wouldn't change the voltage ONLY BECAUSE there is no cur...
by cloudapplepi
Wed Feb 13, 2019 8:05 am
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

With the 3.3v gpio any voltage above 1.8 - 2.0V should be seen as a high input, when assembling a potential divider using resistors I normally aim for 2.9V on the gpio pin , this allows a little leeway for the resistor tolerances, because no resistor is ever its stated value. If you want to see how...
by cloudapplepi
Tue Feb 12, 2019 2:32 pm
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

@cloudapplepi - I'll have a go at trying to explain, because I think Brandon mis-interpreted your "removal of R1" suggestion as to have no connection (open-circuit), whereas I think you were intending to replace it with a straight wire (short-circuit) ....? So I'll assume this was your thought proc...
by cloudapplepi
Tue Feb 12, 2019 12:46 pm
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

This convention to assume that the current goes from - to + when it physically the other way around is something I don't really understand. :? Blame the 18th & 19th century physicists for this. They could see strange things happening when they connected differing metals, with chemicals between them...
by cloudapplepi
Tue Feb 12, 2019 12:40 pm
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

Yes, physical the current flow from - to +. But we dicided to make it goes from + to -. To make it easier for or self. (Easier to calculate for example, you don't need to thing much about the - sing.) Anyway, this explanation we use the convention way. So, let's assume that a F1 car is the current ...
by cloudapplepi
Mon Feb 11, 2019 10:56 pm
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Re: Ultrasonic sensor and voltage division

Thanks for the replies. Much appreciated. Well, if you look at the electrons. They indeed move from the (-) to the (+). However, by convention we decide that the current flows from (+) to (-). More info So, in your case, (if we make the input of the Rpi infinity), the current will go from "power sup...
by cloudapplepi
Mon Feb 11, 2019 6:57 pm
Forum: Automation, sensing and robotics
Topic: Ultrasonic sensor and voltage division
Replies: 19
Views: 1182

Ultrasonic sensor and voltage division

I have a question which probably is stupid, but I just don't understand this. I intend to connect a ultrasonic sensor (HC-SR04) to a robot. There are many guides, I could do it, but I don't understand one thing regarding the resistances. So to my understanding Ground (-) and Echo (+) basically form ...
by cloudapplepi
Fri Dec 07, 2018 11:44 am
Forum: Automation, sensing and robotics
Topic: Can't get robot motors to work (code issue?)
Replies: 6
Views: 677

Re: Can't get robot motors to work (code issue?)

So all you need to do is check for your characters for forwards,backwards,left & right and if non of them are found then execute a stop. like this # Get the curses window, turn off echoing of keyboard to screen, turn on # instant (no waiting) key response, and use special values for cursor keys scr...
by cloudapplepi
Fri Dec 07, 2018 10:34 am
Forum: Automation, sensing and robotics
Topic: Can't get robot motors to work (code issue?)
Replies: 6
Views: 677

Re: Can't get robot motors to work (code issue?)

Just noticed though that the tracks are moving to different directions. :D That can be solved easily, the motor that's running the wrong , just swap the 2 wires round were the motor connects to the motor driver board. Yes, I did exactly that. :-) Now it's driving nicely, but I try to figure out how...
by cloudapplepi
Thu Dec 06, 2018 12:46 pm
Forum: Automation, sensing and robotics
Topic: Can't get robot motors to work (code issue?)
Replies: 6
Views: 677

Re: Can't get robot motors to work (code issue?)

Thanks @pcmanbob. The 3.3 V thing as the issue. :D I just moved the wire from the Raspberry's 5V pin to a 3.3 V pin. Now it works and I can control the motors. I actually thought about it at some point, but completely forgot about it. :D Just noticed though that the tracks are moving to different di...
by cloudapplepi
Wed Dec 05, 2018 7:06 pm
Forum: Automation, sensing and robotics
Topic: Can't get robot motors to work (code issue?)
Replies: 6
Views: 677

Can't get robot motors to work (code issue?)

Hi. I have assembled a robot tank consisting of the following parts: Devastator robot tank kit: https://www.dfrobot.com/product-1477.html A 7A Motor driver: https://www.dfrobot.com/product-1534.html A Raspberry PI3B+ I think everything should be connected properly, also the Raspberry Pins. The Rasbe...

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