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by Z80 Refugee
Sun Jul 15, 2018 10:31 pm
Forum: Automation, sensing and robotics
Topic: Switching ON/OFF High Current Load
Replies: 13
Views: 1154

Re: Switching ON/OFF High Current Load

nuggetchris wrote:
Sun Jul 15, 2018 6:14 pm
If I were to run each magnet simultaneous at half current I would be accepting half force from the magnets.
Are you sure about that? Two magnets each contributing half the normal force, when either one of them can do the job on its own...
by Z80 Refugee
Sun Jul 15, 2018 10:25 pm
Forum: Automation, sensing and robotics
Topic: connecting multiple magnetic switches
Replies: 26
Views: 5505

Re: connecting multiple magnetic switches

So I am suggesting you use 1 resistor and 1 pot for each circuit and I clearly stated you need to set up the voltage output form the potential divider circuit before connecting to the gpio. Do you really want to cloud the education I am trying to provide by arguing your case? Do you have 40+ years ...
by Z80 Refugee
Sun Jul 15, 2018 4:45 pm
Forum: General discussion
Topic: What is a good site to get working roms from?
Replies: 3
Views: 364

Re: What is a good site to get working rooms from?

How about getting the title right, so we know you are talking about ROMs (note capitals) without having to open the thread?
by Z80 Refugee
Sun Jul 15, 2018 4:40 pm
Forum: HATs and other add-ons
Topic: Relay' connected to Rpi Zero W - causes it to freeze
Replies: 29
Views: 2884

Re: Relay' connected to Rpi Zero W - causes it to freeze

1. I use common relays that operate at 5VDC, and triggered by gpio 3.3V. I do not think that labeling it as "Arduino" or "Raspberry Pi" does not make any technical difference. It absolutely does, as several of us have said many times over. For some reason people see a 5V pin on the GPIO and assume ...
by Z80 Refugee
Sun Jul 15, 2018 10:16 am
Forum: Troubleshooting
Topic: Crashing RPi when doing "heavy" stuff
Replies: 13
Views: 972

Re: Crashing RPi when doing "heavy" stuff

Nobody has mentioned the possibility that the workload is causing the PSU to glitch.
by Z80 Refugee
Sun Jul 15, 2018 10:13 am
Forum: HATs and other add-ons
Topic: Hardware Specification of the RPi's
Replies: 22
Views: 2075

Re: Hardware Specification of the RPi's

I don't think there's anything special about the RPi which would make it any different from typical electronics assemblies: as long as the humidity does not condense on the board, it should be OK. That said, I am lead to understand the Compute Module version has full testing/specifications (I have n...
by Z80 Refugee
Sun Jul 15, 2018 10:04 am
Forum: Automation, sensing and robotics
Topic: connecting multiple magnetic switches
Replies: 26
Views: 5505

Re: connecting multiple magnetic switches

if you are going to be using switch on cable runs that long I would suggest you use 5v and an adjustable potential divider circuit for each of your switches, I did it this way on a similar project I did using a pi and had no trouble with voltage drop or false triggering. This is crazy. There is abs...
by Z80 Refugee
Sun Jul 15, 2018 9:14 am
Forum: Automation, sensing and robotics
Topic: Switching ON/OFF High Current Load
Replies: 13
Views: 1154

Re: Switching ON/OFF High Current Load

Hi! For a project I am designing a system of very high-power electromagnets. Each electromagnet is fed a current of around 75A. What voltage? AC or DC? To allow them to cool, I alternate between feeding power between one and the other around every 10 seconds or so. That's nuts. Run both magnets at ...
by Z80 Refugee
Sun Jul 15, 2018 1:35 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: ADC for analog video (possible?)
Replies: 27
Views: 3020

Re: ADC for analog video (possible?)

Fair enough. Thinking some more, there are plenty of video cameras which record to MP4 using similar technology. The difference is the size of the resulting file: the best compression requires significant processing, so they settle for larger files to achieve the throughput.
by Z80 Refugee
Sun Jul 15, 2018 1:26 am
Forum: HATs and other add-ons
Topic: Relay' connected to Rpi Zero W - causes it to freeze
Replies: 29
Views: 2884

Re: Relay' connected to Rpi Zero W - causes it to freeze

Would everybody PLEASE stop buying Arduino boards thinking they will work with the RPi?!!! Yes, they can probably be made to work, but may require modification or even additional adapter circuitry, and connecting just any Arduino board to an RPi without knowing what you are doing risks damage to the...
by Z80 Refugee
Sat Jul 14, 2018 10:32 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: ADC for analog video (possible?)
Replies: 27
Views: 3020

Re: ADC for analog video (possible?)

PiGraham wrote:
Sat Jul 14, 2018 8:06 am
It does both. If you use raspivid to record a video it uses H264 hardware encoder to compress it.
Sure, but that isn't going to be real-time, is it? The accelerator hardware can provide real-time decoding.
by Z80 Refugee
Sat Jul 14, 2018 10:28 am
Forum: Automation, sensing and robotics
Topic: Controlling homemade solenoids using Rpi Z W
Replies: 53
Views: 4331

Re: Controlling homemade solenoids using Rpi Z W

Given that the PI can only output 0.10 mA at 3.3V That's not relevant. To turn on a transistor you need less that 1V, and the RPi is capable of driving 16mA. the solenoid needs 400mA to function At last we have a figure for the solenoid current! Now we are getting somewhere. With 16mA* to switch 40...
by Z80 Refugee
Fri Jul 13, 2018 9:41 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: ADC for analog video (possible?)
Replies: 27
Views: 3020

Re: ADC for analog video (possible?)

6by9 wrote:
Fri Jul 13, 2018 11:00 am
The Pi has hardware acceleration for H264 or MJPEG video encoding.
I think you mean video decoding.
by Z80 Refugee
Fri Jul 13, 2018 9:39 pm
Forum: Automation, sensing and robotics
Topic: Two 6V motors through RPi3B
Replies: 19
Views: 1506

Re: Two 6V motors through RPi3B

Incidentally, you don't actually need to connect pins 1 and 9 to GPIO outputs, they could just go to 5V. The same effect (cutting the current through the motor) can be achieved (in your configuration) by making the inputs both high or both low.
by Z80 Refugee
Fri Jul 13, 2018 9:29 am
Forum: Automation, sensing and robotics
Topic: Controlling homemade solenoids using Rpi Z W
Replies: 53
Views: 4331

Re: Controlling homemade solenoids using Rpi Z W

Yeah, well, I just get the impression you are posting without reading the other posts.
by Z80 Refugee
Fri Jul 13, 2018 9:27 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: ADC for analog video (possible?)
Replies: 27
Views: 3020

Re: ADC for analog video (possible?)

Video streaming is not the same as broadcast digital video or the digitised output of an analogue video signal. Video streaming supplies data on demand, so the display device requests the next packet of data only when it is ready for it. Broadcast and digitised video comes in at full speed, whether ...
by Z80 Refugee
Fri Jul 13, 2018 9:18 am
Forum: Automation, sensing and robotics
Topic: Controlling homemade solenoids using Rpi Z W
Replies: 53
Views: 4331

Re: Controlling homemade solenoids using Rpi Z W

PiGraham wrote:
Fri Jul 13, 2018 9:13 am
The diodes are wrongly connected in any case. They should go across the coil, not in series with it.
I already said that.
PiGraham wrote:
Fri Jul 13, 2018 9:13 am
The button is clearer and definitely seems to switch to GND with a pull-up to 5V. Still bad practice.
I already said that.
by Z80 Refugee
Fri Jul 13, 2018 9:17 am
Forum: General discussion
Topic: Problem with connecting raspberry to Linux
Replies: 34
Views: 2441

Re: Problem with connecting raspberry to Linux

Clearly I don't understand your description of what you are trying to do. I'm working in the dark, because you haven't told me in what way what I wrote in post 2 is wrong.
by Z80 Refugee
Fri Jul 13, 2018 9:14 am
Forum: Beginners
Topic: Force Raspberry Pi to cast Wifi
Replies: 4
Views: 279

Re: Force Raspberry Pi to cast Wifi

I know the Pi (version 3) is capable of casting its own Wifi network, but only if it doesn't see any other Wifi networks for a certain period of time. That doesn't sound right. I'm not an expert on this, but I would expect a Wi-Fi adapter to be configured for a particular operating mode (connecting...
by Z80 Refugee
Fri Jul 13, 2018 9:10 am
Forum: C/C++
Topic: GPIO ouput pin giving High & Low output in Raspberry Pi 3
Replies: 1
Views: 447

Re: GPIO ouput pin giving High & Low output in Raspberry Pi 3

My guess: your GPIO pins are now inputs, so the lines are floating and giving misleading results when you use logic-level rather than analogue monitoring. Check your code initialises everything at the start, so that pins you intend to be outputs are specified as outputs. From power-up, they will be ...
by Z80 Refugee
Fri Jul 13, 2018 9:04 am
Forum: General discussion
Topic: Problem with connecting raspberry to Linux
Replies: 34
Views: 2441

Re: Problem with connecting raspberry to Linux

Because this is a university computer and I don't have a router in this room. Okay, so where do you propose to get a second Ethernet port from? If you had a second Ethernet port, you would need to configure the computer to bridge the network on Port 1 to be available on Port 2. Without a second por...
by Z80 Refugee
Fri Jul 13, 2018 8:57 am
Forum: General discussion
Topic: Problem with connecting raspberry to Linux
Replies: 34
Views: 2441

Re: Problem with connecting raspberry to Linux

I need to connect Raspberry Pi 4 to Linux computer. I need a connection to a computer which has an internet connection, because here is no wifi. It should be a ssh connection via ethernet cable. So you want to access the Internet from the RPi, and aim to use an existing computer with an Internet co...
by Z80 Refugee
Fri Jul 13, 2018 6:24 am
Forum: Automation, sensing and robotics
Topic: Two 6V motors through RPi3B
Replies: 19
Views: 1506

Re: Two 6V motors through RPi3B

WILL THIS PINOUT OVERLOAD MY PI? No. this be problem if I am using a LiPO (boosted to 5V) directly to the pi?! No. The problems you might encounter are if the battery voltage drops below 5V, or if the motor currents are too high for the breadboard (or the contact between the wires and the breadboar...
by Z80 Refugee
Fri Jul 13, 2018 6:06 am
Forum: Automation, sensing and robotics
Topic: Controlling homemade solenoids using Rpi Z W
Replies: 53
Views: 4331

Re: Controlling homemade solenoids using Rpi Z W

If all you are trying to demonstrate is some balls moving up and down, maybe. For a reasonable reproduction of a Braille output device, you need to realise that people who can read Braille will find two characters per second excruciatingly slow.
by Z80 Refugee
Thu Jul 12, 2018 11:55 pm
Forum: Beginners
Topic: how to run .exe file on raspberry pi 3
Replies: 4
Views: 3053

Re: how to run .exe file on raspberry pi 3

.exe files are normally associated with Microsoft Windows (or MS-DOS). The RPi runs a version of Linux (not Windows), and even if you are using Windows 10 IoT Core it still won't run .exe files. The only executables you can run are either specific versions for RaspbianOS (or whatever operating syste...

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