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by ertank
Tue Sep 08, 2020 7:14 pm
Forum: General discussion
Topic: SAM module
Replies: 6
Views: 268

Re: SAM module

topguy wrote:
Tue Sep 08, 2020 6:21 pm
That will definitly add up, yes. But now you have to safely get the keys from that server into the SAMs. And depending on who is running that server that might become hard or very hard ;)
I am happy that is no my job :D
by ertank
Tue Sep 08, 2020 1:38 pm
Forum: General discussion
Topic: SAM module
Replies: 6
Views: 268

Re: SAM module

How many keys are you typically aunthenticating for ? I cant really see how moving the authentication part locally to the pi will save you 2-3 seconds.. the SAM modules are not "faster" at encrypting/decrypting 3DES/AES than any modern computer. So you are only saving "network transfer time" for th...
by ertank
Tue Sep 08, 2020 11:15 am
Forum: General discussion
Topic: SAM module
Replies: 6
Views: 268

Re: SAM module

What you are looking for ( should be googling for ) is "ID000 usb reader". Two examples: https://www.united-access.com/smart-card-reader-omnikey-cardman-6121-usb-5-pcs https://www.cryptoshop.com/gemalto-idbridge-k30-usb-shell-token-v2.html If they mention CCID/PCSC you will need to use "libpcsclite...
by ertank
Tue Sep 08, 2020 8:49 am
Forum: General discussion
Topic: SAM module
Replies: 6
Views: 268

SAM module

Hello, We are using some USB RFID readers with ISO14443A/B support. These devices can read and write DES3Fire Mifare cards. Currently operation is working over a web service which takes 5-6 seconds for a single operation to complete. We are asked to be provided a SAM card for faster operation like o...
by ertank
Mon Jul 13, 2020 7:02 pm
Forum: General discussion
Topic: Copy file from Pi USB to PC
Replies: 6
Views: 244

Re: Copy file from Pi USB to PC

According to your earlier post you have a Raspberry Pi 3 Model B+ USB requires a Host - Slave relationship, as both your PC and RPi are USB Hosts you can not join them together with a USB Cable. Maybe Bluetooth could be an alternative ? I have a lot of different models. I am trying to make an offli...
by ertank
Mon Jul 13, 2020 4:02 pm
Forum: General discussion
Topic: Copy file from Pi USB to PC
Replies: 6
Views: 244

Copy file from Pi USB to PC

Hello, I do not know if there is a specific term used for what I would like to achieve. I have some files in my Raspberry Pi headless. I would like to connect Pi USB to a PC USB and want it to display only these files as read-only for copying to PC. It is not important for me the filesystem. It can ...
by ertank
Thu Jan 30, 2020 11:21 am
Forum: General discussion
Topic: WiFi icon meaning
Replies: 2
Views: 499

WiFi icon meaning

Hello, If you check this picture: https://www.piborg.org/image/catalog/PIBORG/blog/blog/pi-zero-wifi-setup-4.png You will see a disabled item in list of available wifi networks. It has an icon of a computer with stop sign on it. WiFi named "BTWifi-X". This is the first time I see this icon and I wou...
by ertank
Tue Dec 10, 2019 9:35 am
Forum: Advanced users
Topic: Secure app running on Pi
Replies: 9
Views: 798

Secure app running on Pi

Hello, We have a compiled application, GUI, running on Pi. We will be putting that application on an SDCARD/Flash Disk/mSATA and giving away with Pi itself. We would like to protect that application to be copy/paste to another place for reverse engineering, etc. We thought of; 1- Use a strong passwo...
by ertank
Wed Aug 21, 2019 10:28 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

Finally, I had a somewhat success using ADS1115 A/D converter. I used two resistors 100kohm (R1, for + leg), 10kohm (R2, for -leg) for reducing high battery voltage. That design theoretically reduce 50V down to 4.545V. This is as to online calculator here: http://www.ohmslawcalculator.com/voltage-di...
by ertank
Fri Aug 02, 2019 9:25 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

Is your SPI interface enabled? You can check with check with "Raspberry Pi Configuration" program or by looking at /boot/config.txt My SPI interface is enabled. If you connect the battery (-) to GND then you are not doing differential measurements. I did not understand what you mean by that. I woul...
by ertank
Fri Aug 02, 2019 12:02 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

davidcoton wrote:
Thu Aug 01, 2019 11:15 pm
The one obvious thing is that AGND should not be left disconnected, it should be joined to Pi 0V and battery -ve.
That link I shared and my connections are as following:
AGND is connected to Raspberry Pi Ground
Battery (-) connected to Raspberry Pi Ground
by ertank
Thu Aug 01, 2019 10:19 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

I think I fixed my wiring. Used same connections as in here: http://www.noveldevices.co.uk/rp-mcp3008 Battery + is connected to pin 1 of mcp3008 Battery - is connected to Raspberry Pi ground I get a reading once and then I don't have a reading (0 reading) for quite a long time. There is 3 seconds de...
by ertank
Sun Jul 28, 2019 12:03 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

Here is how I wired it up to the RPi. MCP3008 Pin --> Raspberry Pi Header Pin Vdd --> 5V Vref --> 5V AGND --> (floating, not connected) CLK --> SCLK (SPI) Dout --> MISO (SPI) Din --> MOSI (SPI) CS/SHDN --> CE0 (SPI) DGND --> Ground If you want to repeat my setup (and use AAA batteries). MCP3008 Pin...
by ertank
Mon Jul 15, 2019 3:27 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

https://www.aliexpress.com/item/3291407 ... 76c7ooFbkn

How about something like that? It says its communicating using serial. In theory it should be usable with RPi.

BTW, I am after measuring total volts on the serial connected batteries.
by ertank
Mon Jul 15, 2019 9:39 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

chipace wrote:
Sun Jul 14, 2019 8:27 pm
Are you going to show the battery voltages on a LCD screen, or use a web server on the RPi?
I am going to upload readings to a web server in the cloud. RPi will be headless.
by ertank
Mon Jul 15, 2019 9:35 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

I appreciate all help.

I have a basic question: Can I read individual batteries which are serial connected to each other?

What I understand from this drawing is this is fine: https://imgur.com/LN99Wux

Just want to be sure about it.

Thanks & regards,
Ertan
by ertank
Sun Jul 14, 2019 11:11 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

I tried a stack of 4 AAA rechargeable batteries (no resistor divider) and a MCP3008. I was able to read each battery voltage. First battery positive terminal connected to CH0, negative terminal connected to CH1... final battery positive terminal connected to CH6 and negative terminal to CH7. I then...
by ertank
Sat Jul 13, 2019 6:05 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

davidcoton wrote:
Fri Jul 12, 2019 8:50 am
Is this a education project?
Actually, this is a real life customer job (not mine).
I have some basic knowledge of Raspberry Pi GPIO and so I am asked for the job to be completed.
Unfortunately, I did not get any lectures about electrics or electronics.
by ertank
Thu Jul 11, 2019 5:07 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Re: Want to measure battery volts

Thank you to all.

I got updated specs. Batteries are 12V and 4 of them connected together. I have to measure 48V.

I was interested in INV260 unfortunately it is up to 36V.

If I can use resistors I will be back to using them again.

Measurement correctness is required as 1%.
by ertank
Tue Jul 09, 2019 4:21 pm
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 4220

Want to measure battery volts

Hello, - I have a set of 24Volts batteries. (3 or 4 total) - They are connected to this inverter: https://imgyukle.com/i/kK9UrY as power input - Inverter outputs power to a refrigerator of 220Volts. - Everything is mobile. I am asked to measure battery level (volts or percentage or any other way pos...
by ertank
Sun Jun 02, 2019 12:21 pm
Forum: General discussion
Topic: Pi 3 Model B+ 5Ghz to 2.4Ghz WiFi problem
Replies: 0
Views: 192

Pi 3 Model B+ 5Ghz to 2.4Ghz WiFi problem

Hello,

I have my Pi 3 Model B+ device connected to my 5Ghz WiFi network.

For a reason I need to disable my 5Ghz network in my router. Now, I do not see any 2.4Ghz networks in the list.

How can I have my Pi connected to 2.4Ghz network? Any help is appreciated.

Thanks & regards,
Ertan
by ertank
Fri Mar 29, 2019 6:31 pm
Forum: General discussion
Topic: Remove delays for USB only boot or switch USB to be the first cheked in boot sequence
Replies: 10
Views: 765

Re: Remove delays for USB only boot or switch USB to be the first cheked in boot sequence

All it takes is having a tiny vfat boot partition on the SD card with a config.txt file pointing to the SSD's boot partition. Then, instead of waiting for a no response from the built in boot order, it reads the config.txt file from the very first device it tries and immediately goes to the partiti...
by ertank
Fri Mar 29, 2019 4:30 pm
Forum: General discussion
Topic: Remove delays for USB only boot or switch USB to be the first cheked in boot sequence
Replies: 10
Views: 765

Re: Remove delays for USB only boot or switch USB to be the first cheked in boot sequence

You cannot - these are built into the firmware on the Pi (GPU I think) and cannot be changed :cry: You do not normally have to reboot Pi computers that often as even updates go one cleanly normally. Folk around here have had the running for years with no reboot. This is a development device. I choo...
by ertank
Fri Mar 29, 2019 3:20 pm
Forum: General discussion
Topic: Remove delays for USB only boot or switch USB to be the first cheked in boot sequence
Replies: 10
Views: 765

Remove delays for USB only boot or switch USB to be the first cheked in boot sequence

Hello, I am using Raspberry Pi 3 Model B+ I have attached SupTronics X850 V3.0 extension board with a 128GB mSATA SSD. I am happy with the performance so far. One thing I would like to do is directly boot from USB without waiting for a primary and secondary sd fail delays as explained in here: https...
by ertank
Wed Feb 27, 2019 9:51 pm
Forum: General discussion
Topic: Plug and Play USB modem
Replies: 0
Views: 137

Plug and Play USB modem

Hello, In recent years there are usb modems that "just works" with Raspberry Pi. I have difficulties identifying them by looking product specs as Linux is mostly not indicated. - I am looking for a list of devices if such a thing exists. - I would like to hear model numbers of users if that is possi...

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