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by ertank
Wed Aug 21, 2019 10:28 am
Forum: General discussion
Topic: Want to measure battery volts
Replies: 38
Views: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 2228

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: 132

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: 447

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: 447

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: 447

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: 85

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...
by ertank
Fri Feb 08, 2019 7:06 am
Forum: C/C++
Topic: Libnfc example
Replies: 5
Views: 1587

Re: Libnfc example

Hello, I didn't know there is a good documented library function list. Thanks for that. For doing an exclusive connect to card (nfc_initiator_select_passive_target), here: http://www.libnfc.org/api/group__initiator.html#gacbe0fa197206cac99c83ed0152174811 It is indicated that "for an ISO/IEC 14443 ty...
by ertank
Thu Feb 07, 2019 2:57 pm
Forum: C/C++
Topic: Libnfc example
Replies: 5
Views: 1587

Re: Libnfc example

Hello, I can identify tag of the card and print it on screen. Card will always be a DESFire or DESFire EV1 card with 7 bytes UID in my case. Once my main application recognize card ID, it will start to send APDU commands to card and wait for card responses. Now, I need code for sending command line ...
by ertank
Thu Feb 07, 2019 10:11 am
Forum: C/C++
Topic: Libnfc example
Replies: 5
Views: 1587

Libnfc example

Hello, I have a PN532 connected over I2C. I can list device and nfc-poll can read tags of cards. I need to write a small tool for myself to use. However, I have no low level RFID programming knowledge. What I need is: 1- if no command line parameters are passed, wait for a card to get in range infin...
by ertank
Wed May 16, 2018 9:27 pm
Forum: General discussion
Topic: Customer OTP settings - cannot make it to work
Replies: 3
Views: 328

Re: Customer OTP settings - cannot make it to work

In the provided document, there is another command written to close memory addresses to any changes. After using this command anything currently in that memory addresses will be permanent for good is my understanding. That last command makes me think there should be a way to write in any memory addr...
by ertank
Wed May 16, 2018 6:47 pm
Forum: General discussion
Topic: Customer OTP settings - cannot make it to work
Replies: 3
Views: 328

Customer OTP settings - cannot make it to work

Hello, I am using Raspberry Pi 3 Model B+ on a Raspberry Pi Stretch "Linux raspberrypi 4.14.34-v7+ #1110 SMP Mon Apr 16 15:18:51 BST 2018 armv7l GNU/Linux". I have read following page: https://www.raspberrypi.org/documentation/hardware/industrial/README.md After that I used below commands: [email protected]...
by ertank
Wed Feb 07, 2018 9:43 am
Forum: General discussion
Topic: Pin set as pull-up has delay on reading pin low value
Replies: 5
Views: 515

Re: Pin set as pull-up has delay on reading pin low value

It turned out that HotPeriod check in our code is blocking FALLING EDGE detection even if we set it to as low as 1ms. Removing that part of the code gave us required functionality.

We appreciate your helps.

Regards,
Ertan
by ertank
Tue Feb 06, 2018 2:40 pm
Forum: General discussion
Topic: Pin set as pull-up has delay on reading pin low value
Replies: 5
Views: 515

Re: Pin set as pull-up has delay on reading pin low value

// If pin state is still low/high after a given period of time, consider it a pin state change Is it doing this debouncing count? That would ignore short pulses. This is manual slowing down of the sensor. It is especially requested by customer because sensors sometimes pick-up small particles (text...
by ertank
Tue Feb 06, 2018 2:08 pm
Forum: General discussion
Topic: Pin set as pull-up has delay on reading pin low value
Replies: 5
Views: 515

Re: Pin set as pull-up has delay on reading pin low value

What is your software? There are various ways to detect a momentary change in a GPIO input and if software isn't looking at pin state when it changes then the change is missed. If you use a polling loop to repeatedly read the input state how fast does the loop cycle? If you signal is low for only 1...

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