Raspberry Pi Forums

Brandon92

Maybe a stupid question, but are you using pull-up resistors?

Brandon92

Hello,

A tvs diode is indeed a good component to get rid of the voltage spikes. And a aditonal rc filter can do also a lot but not everything.

Brandon92

Here you can find the formula the change the adc value to the "real" input voltage. And about the translation to ppm. You need to read the manual / datasheet of that specified sensor. They will tell you the ratio between the output voltage and the PPM.

Brandon92

As a slide remember. You can not use the power adapter and the battery at the same time. If you choose to use that kind of battery. Bad thing will happens. (You can't charge that type of battery in this way) As for the connection, assuming that your power supply is the right one: Place from the posi...

Brandon92

I thought I would share my progress with my 16-channel device to read the which of 24vac lines are on. I only have one column of 4 A3700's wired and even then not 100%. You can see where I'll put the mcp23017. Thank you, forum buddies, for the suggestion to use this chip. You see a mini-usb connect...

Brandon92

The l9110 is capable of delivering a continuous current of 800mA. And it will except a current spike of 2A. But, for a short amount of time.
And it will provide that with the voltage drop, as already mentioned.

By the way, you use a computer. Why are u choosing for a battery and not a power adapter?

Brandon92

@davef Well, it also depends where this PWM signal is used for. As a example, if this signal drives a inductive/ capacitive load. This could generate voltage spikes. That can possibly kill the Rpi. And in the case you can't drive a led with your PWM signal. If it is for example a sense line. Then yo...

Brandon92

Is there a specific reason for you to use in total 6 battery. In stead of one big one? Because I think one big one works also, and easier to manage and connect everything to each other.

Brandon92

How long do you want to last the product on one battery charge. And I believe that only 3 run motors at the same time?

Brandon92

To make a small note. You can not use the 3.3v rail from your Rpi to power your motors. So, you need a extra power supply for that. And how much current draw you motor?

Brandon92

Yes. That is possible.

Brandon92

If I may take a bit of your time to clarify: Was my assumption that each device will take as much amperage as they need? (I am basically trying to pick up facts from posts that I see, but I'm not that good at connecting the dots when it comes to electronics, so I do need some validation :D) Am I in...

Brandon92

Okay. That is good then. I also see that you have enabled the ac coupling option. And you need to turn it in dc coupling.
You can see this because the ground level of your signal is not at the same level as the channel label.

But despite that, your signals are looking good

Brandon92

I hope this diagram is more clear for you, about how to connect it correctly. If you have quistion about this, or I need to check it. Let me know.

: pwmled_con_scope.png (101.62 KiB) Viewed 1863 times

Okay, your resistor is correct.

Brandon92

I am a little bit confused. Is it true that your FTDI USB to TTL UART serial cable is noisy therefore your LUA script uploading using ESPlorer is not reliable? As I mentioned earlier, one TaoBao shop said that many people have noisy USB to TTL cable and one solution is to buy their cable with a big...

Brandon92

Wat is het type nummer dan?

Brandon92

Ehm okay. Let's go back to something simple. Can you build this schematic: https://elinux.org/images/3/31/EGHS-LEDhigh_output2.jpg And connect the one probe to the base and the other to the emiter of the transistor. Amd the gnd to the gnd. And use for r2 the same resistor as you use write now. And i...

Brandon92

This is my final year project and the presentation day is in 2 weeks! I assume that you know this important deadline at the beginning of your project / year. And that the project is longer than 4-10 weeks. So, what did you do / try, in that time base? And what for kind of study are you following?

Brandon92

Ik zou verwachten dat die gegevens in de handleiding van je omvormer staan.

Brandon92

The space/taps are not good in you program, try this one: #!/usr/bin/python import time import RPi.GPIO as GPIO from time import sleep GPIO.setmode(GPIO.BOARD) GPIO_TRIGGER = 11 GPIO_ECHO = 13 Motor1A = 16 Motor1B = 18 Motor1E = 22 Motor2A = 19 Motor2B = 21 Motor2E = 23 GPIO.setup(Motor1A,GPIO.OUT) ...

Brandon92

Okay. And what doesn't work exactly?

Brandon92

I think you get more response if you post the code in this topic. And the exact error that you are getting. Personally I don't want to search for the pace of code that's "not" correct on a website.

Brandon92

That is indeed a option what danjperron mention. There is also a other option to "make" a ideal diode. As showed in this application note.

Brandon92

Hello, Is the last scope image with the fan connected? Because all the signals are not what I would expect. And by looking at your images, the connection looks good. If your Rpi signal is 0V, so the yellow signal on the scope is at the same level as the "B'. If that is the case, I would expect the b...

Brandon92

100A, that sound like a industrial environment. And what is you knowledge about this subject. If I can ask. Because, this is not child's play. And if you really want to measure that kind of current. You need indeed some kind of current probe that you posted in you first post. And like danjperron men...

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