5
votes
Accepted
Recording landline phone calls
My approach to this would be to do everything I possibly could to avoid interfacing the Pi directly with the phone line. It's definitely achievable, but it sounds a lot harder than I like my spare ...
- 10.7k
4
votes
What hardware peripherals might be capable of reading 6.144, or better yet, 9.216 megabits/second?
When sampling parallel ADC's the synchronization becomes more problematic than the raw bandwidth. You have not really made it clear what your application is but I assume audio.
Your quickest turn ...
- 3,013
4
votes
What hardware peripherals might be capable of reading 6.144, or better yet, 9.216 megabits/second?
There is a big difference between 6..9 MHz clock speed (which according to the BCM2835 datasheet is derived from 150MHz core_clk with a power-of-two 16-bit integer divider CDIV, I assume the Pi 4 is ...
- 28.2k
3
votes
What hardware peripherals might be capable of reading 6.144, or better yet, 9.216 megabits/second?
To answer your topic question.
The SPI peripheral can work at those speeds. I2C can not. I do not know about I2S.
However I have not heard of any software which allows continuous SPI readings at ...
- 71.7k
3
votes
PH-4502C pH Sensor Calibration and ADC using MCP3008, PCF8591, and ADS1115
I recommend this repository for ADS1115 for RPi in Python and for Arduino.
Calibration
Reset
Read the values
https://github.com/DFRobot/DFRobot_PH
You can adapt to your project and works properly. ...
- 91
3
votes
RPi 3 Model B: PSU, Measuring Voltage & Amps
Several vendors market the "USB Doctor", a gadget that plugs into a USB port and measures voltage and the current through its USB output. They are small and cheap but the one I bought from Adafruit ...
- 31
2
votes
Correcting for GPS error
GPS has what is known as DOP or Dilution Of Precision. It means things aren't as accurate as you might want. There are 4 such values: TDOP, two HDOP values that are often merged, and VDOP. (Those ...
- 225
2
votes
Accepted
Wiring that won't damage my pi
You need to do a power budget.
I would recommend a external power supply for 5volt devices.
You also need to interface the PIR's 5volt output to Raspberry Pi's GPIO of max 3,3volt. Either you can do ...
- 2,836
2
votes
PH-4502C pH Sensor Calibration and ADC using MCP3008, PCF8591, and ADS1115
From How to use a pH sensor with Arduino
Calibrate the sensor
As we can see that there are two potentiometers in the circuit. Which
it is closer to the BNC connector of the probe is the offset
...
- 2,796
2
votes
PH-4502C pH Sensor Calibration and ADC using MCP3008, PCF8591, and ADS1115
Update 2019oct07hkt1128
Newbie FAQ
Q1. How to adjust offset？
A1. Following Part1 Section 1,
(1) Power supply 5V to module,
(2) Do the 3 offset calibrating steps until your multi-meter read about 2....
- 4,787
2
votes
How can I determine if a given touchscreen is compatible?
Well, I had the same problem and had to find out that this question is a rather hard one.
This blog entry introducing the official 7" RPi display explains some of the most important keywords involved ...
- 910
2
votes
Accepted
Should I power RaspPI + peripherals from hub or use GPIO?
For one, you need a very good hub that can support a Raspi. Most won't deliver enough power. Also, the PD boards will drain a respective amount of power themselves (unfortunatelly, your link does not ...
- 906
1
vote
Peripherals power usage
Your measurements depend on how you have everything connected. Lets assume you are using the GPIO pins. Using figures from the original Pi they say a MAX of 16mA per pin and a total MAX of 51mA for ...
- 17.3k
1
vote
How to restart/release rfcomm for bluetooth communication?
rfcomm is one of the tools that has been deprecated by the BlueZ team as working at that low level can lead to unpleasant things happening on the system because those tools by passed the the bluetooth ...
- 1,500
1
vote
Accepted
ADF support for scanadf on HP scanner
It seems I don't need scanadf. I can scan from ADF using scanimage:
sudo scanimage --source "ADF duplex"
That might be a specific option for the HP 8200 series.
Unfortunately, I always get a ...
- 2,467
1
vote
Raspberry Pi 3B+ BLE peripheral : Android can't retrieve services list, OK with iPhone and Win10
I have found to get reliable connection to Android phones it is best to put the controller into le only mode. This is done in the /etc/bluetooth/main.conf file. Ensure that it contains the following:
...
- 1,500
1
vote
Raspberry Pi 3B+ BLE peripheral : Android can't retrieve services list, OK with iPhone and Win10
"Android" is a broad family of devices, each with different BT hardware and drivers, and as a result with different behavior and quirks. If you own a device from a major brand, searching or asking ...
- 28.2k
1
vote
Accepted
Ejecting USB dslr camera
It depends on how your camera detects a USB connection - whether it's by detecting that's power is provided through the USB cable, or whether by detecting that there's an actual USB connection ...
- 161
1
vote
Ejecting USB dslr camera
You can download the eject package with sudo apt-get install eject. Here's the eject syntax.
Remember, in order to eject a device, you first need to unmount it.
- 713
1
vote
Stream remote pi+rasp camera to another computer?
An alternative is the RPi Web Cam Interface:
https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=63276
- 7,028
1
vote
Stream remote pi+rasp camera to another computer?
have you had a look at motioneyeos. It's a pre-built distro for doing just that. You get a variety of options for controling the camera framerate etc or you can choose to have it as a simple IP camera ...
- 459
1
vote
Accepted
Only allow a specific peripheral to be connected to a USB port
udev rules are probably the best way to handle this. This answer is probably a good starting point.
Basically you would create a rule that matches all devices except yours and have udev disable the ...
- 3,014
1
vote
Wiring on RPI3 when connecting two peripherals - microcontrollers simultaneously
You should use Typical SPI bus: master and three independent slaves.
In this topology you are differentiating the two peripherals with the CS (chip select) line. Not Daisy-chained SPI bus connection.
...
- 23
1
vote
SPI DMA and continuous transfers
I believe the current Linux /dev/spidevx.y driver for the Pi supports DMA. I believe it automatically uses DMA if the transfer is over a certain size (below this size the overhead of setting up DMA ...
- 71.7k
1
vote
How to interface to a Pi without knowing its IP or having a large HDMI monitor?
If you're working with Arduino, you may already have a UART cable handy. You can use that to interface with the Pi via the serial pins.
Any cheap UART interface will do for the purpose. I personally ...
- 7,156
1
vote
How to interface to a Pi without knowing its IP or having a large HDMI monitor?
Ensure libnss-mdns is already installed (it should be by default).
Connect a USB to Ethernet adapter to the RPi (I got j5create USB 3.0 Gitabit Ethernet Adapter JUE130 and it works out of the box). ...
- 327
1
vote
Raspberry Pi (Low) Power - Damage?
(Edit) (It may be possible but probably not likely. What happened to me was that I had a bad HDMI cable)
I think it may be possible to damage the board its self. but it would have to be investigated ...
1
vote
Soldering Components onto RasPi headers
I would definitely recommend you not to solder directly to your Pi. In my opinion, it is too easy to do damage to the device with the soldering iron.
Consider using some kind of connector between the ...
- 2,929
1
vote
How can I automatically mount USB hard drives (regression)?
It is possible that you previously had Thunar (the XFCE file manager) which has a thunar-volman extension that handles automounting. In Thunar settings there in an option Mount removable media when ...
- 421
1
vote
What kind of connector do I use for the Pi's GPIO pins?
I'm not sure whether you mean the GPIO connector on the Pi board itself or something to mate with it. I've been looking for the former, and after much research and many dead ends found that the ...
- 11
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