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by markatlnk
Wed Nov 24, 2021 6:39 pm
Forum: General discussion
Topic: Will you make microchips like RP2040, but with leads (QFP)?
Replies: 19
Views: 621

Re: Will you make microchips like RP2040, but with leads (QFP)?

The existing RP2040 chip isn't that hard to solder. I created a quick design in KiCad and it seems to work just fine. I would have even hand soldered it if it wasn't for the ground pad in the middle. I had a stencil created that was just the processor and mounted that first. All of the other parts I...
by markatlnk
Sun Aug 01, 2021 3:36 pm
Forum: General discussion
Topic: Internet facing server
Replies: 7
Views: 425

Re: Internet facing server

I have had an internet facing server for years. It was a Pi 2B for a long time, it is a Pi 4 with 2 gig of RAM at this point. The only thing I would suggest other than the security things already mentioned is to run it from a SSD instead of the SD card. When I was running the Pi 2, it used the SD ca...
by markatlnk
Thu Jul 15, 2021 8:01 am
Forum: General discussion
Topic: Argon One m.2 case - temperatures
Replies: 5
Views: 626

Re: Argon One m.2 case - temperatures

I am running the m.2 case with a loaded CPU and a 250G drive in it. Works great and the cpu temp is at 50.1C at the moment. I did adjust it so the fan is just on. Under full load the fan cycles on and off and that was a bit annoying so I just set it to run all the time.
by markatlnk
Fri Jun 18, 2021 6:41 pm
Forum: General discussion
Topic: Can Raspberry Pi appear as serial-port device to a computer over USB
Replies: 9
Views: 386

Re: Can Raspberry Pi appear as serial-port device to a computer over USB

Nice try, but that didn't do it. Really isn't a huge deal, Just saw the first post and thought that would be a more reliable way to talk with my zeroW. I use a mac and sometimes it gets really picky with the NDIS driver network stuff. I just need to get in to setup wifi when on the road. Will be tra...
by markatlnk
Fri Jun 18, 2021 2:10 pm
Forum: General discussion
Topic: Can Raspberry Pi appear as serial-port device to a computer over USB
Replies: 9
Views: 386

Re: Can Raspberry Pi appear as serial-port device to a computer over USB

Using the piOS, it didn't seem to work, I think you still need to start services on ttyGS0. I couldn't find a way to do that from the /boot directory. You need to mount the root (ext4) partition and create a link there. Go to (ROOT)/etc/systemd/system/getty.target.wants and create a symlink ln -s /l...
by markatlnk
Tue Mar 02, 2021 11:57 pm
Forum: General discussion
Topic: Using NPN 2N3904 as a switch for 12v DC fan.
Replies: 35
Views: 1624

Re: Using NPN 2N3904 as a switch for 12v DC fan.

One other thing to think about is the "gain" of the transistor. The 2N3904 can have a gain as low as 30. The output voltage will be 3.3V, the voltage on the base will be about 0.7. That is a 2.6V drop on the resistor of 1K so you get 2.6mA. With a gain of 30, you only get about 78mA of col...
by markatlnk
Sun Jan 31, 2021 2:54 pm
Forum: General
Topic: Silkscreen labels of pins
Replies: 6
Views: 599

Silkscreen labels of pins

I know the board isn't that big, but when you solder pin into it and plug it into a breadboard, you can't see the labels on the pins anymore. If I solder the pins in from the top, then I can't press the BOOTSEL button and the LED is facing down. I might do this anyway as once the development system ...
by markatlnk
Wed Jan 27, 2021 3:05 pm
Forum: General discussion
Topic: Adding RAM to Pi
Replies: 69
Views: 118295

Re: Adding RAM to Pi

I wrote a large program that looks for DNA mutations in over 2,000 different sequences. Ran it on a rather large super computer and it took about 11 hours on 500+ cores. With the 64bit OS on an 8 G Pi I thought it would run. I have a 500G SSD that the OS is running off of. Compiled just fine, I sai...
by markatlnk
Wed Jan 27, 2021 12:52 am
Forum: General discussion
Topic: Adding RAM to Pi
Replies: 69
Views: 118295

Re: Adding RAM to Pi

I wrote a large program that looks for DNA mutations in over 2,000 different sequences. Ran it on a rather large super computer and it took about 11 hours on 500+ cores. With the 64bit OS on an 8 G Pi I thought it would run. I have a 500G SSD that the OS is running off of. Compiled just fine, I said...
by markatlnk
Wed Dec 23, 2020 6:59 pm
Forum: General discussion
Topic: How many RPI do you need?
Replies: 28
Views: 1895

Re: How many RPI do you need?

I agree with just one more concept. I have 25 although several have wandered off to students and I really don't expect them back. I teach so that is really a good thing. The latest one is an 8G pi4 with a 500G SSD (no SD card) running the 64 bit version of the OS. It has been rock stable. Almost a y...
by markatlnk
Tue Dec 08, 2020 4:00 pm
Forum: General discussion
Topic: Is 15.4W Enough Power from PoE Port for RPi 4B?
Replies: 22
Views: 1642

Re: Is 15.4W Enough Power from PoE Port for RPi 4B?

I have several Pi 4 machines running off of cheap POE adapters just used a micro USB to USB-C converter. Most have an external SSD instead of SD cards for the os. haven't had an issue with any of them. One also has one of those low cost fan coolers on it, again no problems. I do have a Pi 3 with the...
by markatlnk
Thu Dec 03, 2020 2:07 am
Forum: General discussion
Topic: Comparison between A73 cortex vs desktop CPU's
Replies: 20
Views: 1714

Re: Comparison between A73 cortex vs desktop CPU's

By increasing the number of transistors you can do a bunch of things that would speed up execution. But running those extra transistors take more power. It also takes power to switch a signal from a logic low to a logic high or high to low. So each time it switches it needs a bit of energy. When you...
by markatlnk
Fri Nov 06, 2020 7:36 pm
Forum: General discussion
Topic: Getting wires into an airtight box
Replies: 13
Views: 740

Re: Getting wires into an airtight box

If it is an insulated wire, especially stranded, you get leakage. I suggest epoxy a small solid piece of wire through and connect on both sides.

Mark
by markatlnk
Sun Aug 02, 2020 1:33 pm
Forum: General discussion
Topic: Ice tower pi4
Replies: 11
Views: 1783

Re: Ice tower pi4

I have a couple of those coolers, they work great. It came with a simple pad that I used and it is fine. Running the 64bit OS on an 8G Pi4 with no SD card and a 500G SSD for the hard drive. It is not overclocked and just checking it is running 43.3C at the moment, but the office is really toasty on ...
by markatlnk
Thu May 14, 2020 1:32 pm
Forum: Python
Topic: Pi 4 with Kivy works but touchscreen gives double hits
Replies: 0
Views: 292

Pi 4 with Kivy works but touchscreen gives double hits

I have two nearly identical systems, one is a pi 3 the other is the pi4. Both systems have the Raspberry Pi 7" display touchscreen. Both systems are up to date on everything. Both are running without a desktop environment. I managed to follow instructions on https://kivy.org/doc/master/installa...
by markatlnk
Thu Apr 02, 2020 8:51 pm
Forum: General discussion
Topic: How to set GoDaddy domain to show my Raspberry Pi hosted website?
Replies: 5
Views: 1683

Re: How to set GoDaddy domain to show my Raspberry Pi hosted website?

I have had this running for years. The only difference is I pay my internet provider (Allo) for a static IP address. That makes things a bit easier.

You can go look at it if you wish at zjunk.net

Mark
by markatlnk
Fri Mar 27, 2020 2:28 pm
Forum: General discussion
Topic: [REQUEST] - Mail server (Exchange alternative)
Replies: 5
Views: 1748

Re: [REQUEST] - Mail server (Exchange alternative)

I am running a full dovecot system with postfix as my outgoing MTA. Been running it for years on a pi 2 and it does just fine. Updated to a pi 4 last December. It also runs a full Wordpress blog system. You will need to deal with the huge amount of spam. I think my email gets something like 200+ spa...
by markatlnk
Fri Mar 27, 2020 2:16 pm
Forum: General discussion
Topic: Installing Folding@Home client to fight Corona/COVID-19
Replies: 5
Views: 3560

Re: Installing Folding@Home client to fight Corona/COVID-19

I have the project running on a 6 core 2018 MacBook Pro, but even it only gets one project every couple of days. Even those complete in a couple of hours. So it is running less than 20% of the time. I do have a pi running Seti@home, but that is shutting down work at the end of this month. I understa...
by markatlnk
Tue Feb 18, 2020 12:59 am
Forum: General discussion
Topic: Question: Pi 4 as a web server
Replies: 11
Views: 1303

Re: Question: Pi 4 as a web server

My server only boots from the SD card, its main / directory is on the SSD. It is the same way I did it on the Pi2. The /boot directory is all that is needed there. There are ways to get it to boot from the SSD, but I never bothered. The SD card isn't written to except for updates, so it shouldn't ev...
by markatlnk
Sat Feb 15, 2020 2:57 pm
Forum: General discussion
Topic: Question: Pi 4 as a web server
Replies: 11
Views: 1303

Re: Question: Pi 4 as a web server

I have been running a web site with email system on a pi for many years. I updated it from a pi2 to a pi4 last year. I have a static IP with 1G up and down. You are welcome to go look at it. zjunk.net We use it share our vacation trips in a Wordpress blog, I take a few photos and my wife writes. I t...
by markatlnk
Sat Jan 04, 2020 2:54 pm
Forum: General discussion
Topic: WordPress Questions
Replies: 2
Views: 376

Re: WordPress Questions

Depends on how you are connected to the internet and your network settings. When you say my network, I assume you have setup some sort of sub net. Easy way to tell is to look at your ip address of the Pi. If it is a non routable address, it would only be local. To actually get a Pi setup so the outs...
by markatlnk
Thu Nov 14, 2019 1:18 am
Forum: General discussion
Topic: Bitcoin Mining, is it worth it?
Replies: 32
Views: 51319

Re: Bitcoin Mining, is it worth it?

You could ask the same question about buying a fancy sports car or truck. We as humans each learn different ways. When I encourage students to learn about things, you attempt to find out what they are interested and see if you can link it to that. I could point out web sites for people to learn abou...
by markatlnk
Mon Nov 11, 2019 8:34 pm
Forum: General discussion
Topic: Bitcoin Mining, is it worth it?
Replies: 32
Views: 51319

Re: Bitcoin Mining, is it worth it?

That sounds like a fun project. As you suspect, not worth it from a financial point of view, but fun. I teach electrical engineering for a living. You learn a lot from the work putting it together. Now the technical questions, super caps or batteries? How big of panels do you have? Will they track t...
by markatlnk
Mon Nov 11, 2019 3:51 am
Forum: General discussion
Topic: Bitcoin Mining, is it worth it?
Replies: 32
Views: 51319

Re: Bitcoin Mining, is it worth it?

As others have said, for profit, nope. Even the Pi4 is very slow. But for those that just want to get lucky, there are a couple of sites out there that let you mine in lottery mode. If you are the lucky one that finds the block, you get 95-99% of the value. For bitcoins, that is something like $100K...
by markatlnk
Wed Oct 23, 2019 3:03 pm
Forum: Advanced users
Topic: Having issues with MacOS Catalina and gadget mode
Replies: 5
Views: 2882

Re: Having issues with MacOS Catalina and gadget mode

Setting the MAC address to a specific value did fix my problem. Thanks for that. I did it in the cmdline.txt file. I added the following to cmdline.txt: modules-load=dwc2,g_ether g_ether.host_addr=00:22:82:ff:ff:20 g_ether.dev_addr=00:22:82:ff:ff:22 I put it after the rootwait I should have thought ...

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