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by Brandon92
Fri Oct 15, 2021 5:07 pm
Forum: Beginners
Topic: Li-Ion battery power for Raspberry Pi 4 advice needed
Replies: 11
Views: 472

Re: Li-Ion battery power for Raspberry Pi 4 advice needed

Okay, you can post your schematic if you want us to take a look at it.
by Brandon92
Fri Oct 15, 2021 4:39 pm
Forum: Beginners
Topic: Li-Ion battery power for Raspberry Pi 4 advice needed
Replies: 11
Views: 472

Re: Li-Ion battery power for Raspberry Pi 4 advice needed

You can also not discharge the battery to much, this will damage the battery or even be dangerous. Depending on the exact type you can not discharge it below a certain voltage.
Also, how are you going to charge them?
by Brandon92
Fri Oct 15, 2021 1:07 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi 4 / Arduino Due / MCP4725 I2C Question
Replies: 3
Views: 311

Re: Pi 4 / Arduino Due / MCP4725 I2C Question

Can you give us a diagram of how you connected everything together
by Brandon92
Thu Oct 07, 2021 6:12 pm
Forum: Automation, sensing and robotics
Topic: Pressure monitoring using MPX2010GP and ADS1115
Replies: 10
Views: 647

Re: Pressure monitoring using MPX2010GP and ADS1115

What did you change so that it is working now?
Could be helpful for others as well
by Brandon92
Thu Oct 07, 2021 6:09 pm
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

I think indeed the first step is to test if it is possible to detect the tubes with optics. With the develop board that is provided by the manufacture. Also we have found one type that could work. But the best think is to take a look at a couple and to which one is the best for this applications. Th...
by Brandon92
Wed Oct 06, 2021 5:10 am
Forum: Troubleshooting
Topic: LTE USB Modem does not always work
Replies: 3
Views: 263

Re: LTE USB Modem does not always work

The LTE dongle use a lot of current when it is transmitting data. These pulse current are to large for the Rpi and are limited by the Rpi. So the voltage for the dongle will drop below a certain level. And eventually the dongle will crash.

By the way. A USB 3 (or higher) hub should work fine for you.
by Brandon92
Tue Oct 05, 2021 8:16 pm
Forum: Troubleshooting
Topic: LTE USB Modem does not always work
Replies: 3
Views: 263

Re: LTE USB Modem does not always work

Did you insert the LTE USB Modem direct into the USB port of the Rpi. If this is the case than it will not work. You need to use a different power supply for the LTE USB Modem. For example a powered USB hub. As stated here Power supply Very high-current devices, or devices which can draw a surge cur...
by Brandon92
Mon Oct 04, 2021 7:27 pm
Forum: Off topic discussion
Topic: Alternate Power Supply to Raspberry Pi 4 Model B
Replies: 7
Views: 794

Re: Alternate Power Supply to Raspberry Pi 4 Model B

You don't need to use the USB-C connector, there are 5V and GND connections on the 40 pin GPIO connector that are also fine for powering the Pi. It is worth noting that this is not possible on the Pi 400. On that model the GPIO 5V pins are switched and can not be used to power the Pi. Is this true,...
by Brandon92
Sun Oct 03, 2021 11:58 am
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

We decontaminate the racks using an ethanol/isopropanol mixture (70/30, I think). Typical plastics, including FDM materials such as polylactic acid, are resistant to it (we tested). Any residual disinfectant should not be electrically of concern, as alcohols are poor conductors (MOhms/cm). Okay, I'...
by Brandon92
Sun Oct 03, 2021 9:46 am
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

I think there are (for now) two direction we can go: optical detection or using switch. And the big question is what we are going to use. I think the big question for now is. Does it need to be easy cleanable or doesn't it matter. Switch When it has to be easy to clean than a normal switch is not a ...
by Brandon92
Sat Oct 02, 2021 6:28 pm
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

As a quick example. You can connect the 24 VCNL3020 to 4 TCA9548A then you can control and read every sensor on the I2C bus. Then you can also use the 24 Interrupt output of the sensor to go to a digital pin of the Rpi. But you can also connect them al to each other. And when that pin is changing. Y...
by Brandon92
Sat Oct 02, 2021 5:36 pm
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

all things considered, this one may be a good choice for my application. I don^t understand whether the proximity trigger is tunable. 20mm would be OK, but if it trips already at 200mm it cannot be used: https://www.vishay.com/docs/84150/vcnl3020.pdf That sensor can measure the distance between 1 t...
by Brandon92
Sat Oct 02, 2021 1:41 pm
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

this would be the idea: https://imgur.com/iIBWLm3 In the basic this idea could work. However cleaning them would be a nightmare or when someone would spill something over the switches. The cleaning solution / or the spill could also damage the switch itself. Maybe you need to take a look at a optic...
by Brandon92
Fri Oct 01, 2021 8:18 pm
Forum: General programming discussion
Topic: AD9850 phase calculation
Replies: 7
Views: 506

Re: AD9850 phase calculation

Did you have a look at the datasheet of your chip. In that datasheet the following is told about the 5 bit data: The device also provides five bits of digitally controlled phase modulation, which enables phase shifting of its output in increments of 180°, 90°, 45°, 22.5°, 11.25°, and any combination...
by Brandon92
Fri Oct 01, 2021 7:53 pm
Forum: Automation, sensing and robotics
Topic: evaluation of 24 digital inputs
Replies: 61
Views: 3342

Re: evaluation of 24 digital inputs

Is it a school project?
And you need to give us more information about your project to give you a detailed answer.
by Brandon92
Fri Oct 01, 2021 7:48 pm
Forum: Automation, sensing and robotics
Topic: Pressure monitoring using MPX2010GP and ADS1115
Replies: 10
Views: 647

Re: Pressure monitoring using MPX2010GP and ADS1115

What for multimeter did you use, and how did you measured it. Because the full scale change what the sensor can do is only 0.025V (25 mV)), see figure 9 in the datasheet. And this is the voltage difference between the two output of the sensor. So you need to connect the pressure sensor deferential t...
by Brandon92
Fri Oct 01, 2021 7:20 pm
Forum: Off topic discussion
Topic: Power-on delay with 555 Timer for Raspberrypi
Replies: 20
Views: 1535

Re: Power-on delay with 555 Timer for Raspberrypi

A micro-controller is not a replacement for a 555 in many cases. It has a much wider power supply operating range and can drive higher currents when needed. I agree. Micro can replace most devices like this only 99% of the time. lol As far as drive ability an AVR chip with paralleled pins can suppl...
by Brandon92
Sun Feb 28, 2021 2:12 pm
Forum: Beginners
Topic: PWM AC Dimmer
Replies: 25
Views: 7835

Re: PWM AC Dimmer

The leading edge methode is not ideal to dim those lights. You need a trailing edge dimmer for those light. Also some led are not dimmable at all. And zero cross detection is not the problem, in fact you need that. Here you can find more information about it: https://www.lamps-on-line.com/leading-tr...
by Brandon92
Fri Feb 26, 2021 7:18 pm
Forum: Beginners
Topic: PWM AC Dimmer
Replies: 25
Views: 7835

Re: PWM AC Dimmer

What is the exact light that you are using. It is possible that the light will not dim via the "Leading Edge Dimmer" methode.
by Brandon92
Fri Jan 08, 2021 9:28 pm
Forum: Automation, sensing and robotics
Topic: Problem measuring DC current with ADS712 (with code)
Replies: 8
Views: 537

Re: Problem measuring DC current with ADS712 (with code)

What is the type of load that you have connected to the ADS712 when you see the strange behavior. And how did you connected everything together. Did you add for example some decouple capacitors at various places? And are you using long wires.
by Brandon92
Wed Jan 06, 2021 6:44 pm
Forum: General discussion
Topic: Reading an engine's RPMs with raspberry pi
Replies: 20
Views: 1822

Re: Reading an engine's RPMs with raspberry pi

Okay, unfortunately the input current is not stated in that datasheet. So I can not tell you if this is going to work for you. Also because I didn't do if for myself. I would make one that use as less as current as possible. Or if you know how much current that sensor can deliver you can design it t...
by Brandon92
Tue Jan 05, 2021 6:32 pm
Forum: General discussion
Topic: Reading an engine's RPMs with raspberry pi
Replies: 20
Views: 1822

Re: Reading an engine's RPMs with raspberry pi

Thanks Brandon92, altering the signal too much is exactly what I am trying to avoid. In a similar vein, this circuit was suggested to me: electrical diagram.JPG I am no expert though so I've been trying to make sure I understand how to wire this up. If I use this approach though there would be no n...
by Brandon92
Mon Jan 04, 2021 5:43 pm
Forum: General discussion
Topic: Reading an engine's RPMs with raspberry pi
Replies: 20
Views: 1822

Re: Reading an engine's RPMs with raspberry pi

The "problem" with a (led) optocoupler is that the leds use a reasonable amound of power (current). And I don't know if the output of that sensor can handle that. If you load the sensor to much it could be damaged and/or the output of that sensor could be change to much that your car can't...
by Brandon92
Thu Dec 31, 2020 4:12 pm
Forum: General discussion
Topic: Reading an engine's RPMs with raspberry pi
Replies: 20
Views: 1822

Re: Reading an engine's RPMs with raspberry pi

Is that tacho sensor also going to a other part of the car that control the car. When you connect something in parallel you will change the signal slightly. And if that signal is changed to much the car doesn't react to it as it should. At the Rpi side it is importend that when it crashed or somethi...
by Brandon92
Fri Dec 25, 2020 1:08 pm
Forum: Troubleshooting
Topic: How do I power a 12v device and power my pi with a 12v battery
Replies: 14
Views: 731

Re: How do I power a 12v device and power my pi with a 12v battery

The IRF520 has a maximal gate threshold voltage of 4 V and a minimum of 2 V. So it is possible that the MOSFET will not be turned on when the gate voltage is 3.3 V. When the gate voltage is 4.5 V it can switch only a current of 1 A by drain-to-source voltage of 10 V. The relay board is good if you h...

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