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by MarkTF
Fri Oct 11, 2019 7:24 pm
Forum: General discussion
Topic: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?
Replies: 10
Views: 370

Re: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?

Yes, I"m just wondering if you plug a non-Quick Charge device into the Quick Charge 3.0 port, will it provide the voltage and amps required from the device. In this case, will the Pi 4 request 5V/3Amp, and will the Quick Charge 3.0 port provide that on each port? The Pi won't negotiate anything on ...
by MarkTF
Fri Oct 11, 2019 5:48 pm
Forum: General discussion
Topic: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?
Replies: 10
Views: 370

Re: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?

I need to power 4 Raspberry Pi 4B clusters and was wondering if this charger will consistently provide 5V/3A to all 4 Pi's? https://www.amazon.com/dp/B07GGMLSD3/?coliid=I3A004O8XVNRO7&colid=2I5CGTBT9RPVY&psc=1&ref_=lv_ov_lig_dp_it There's no benefit to using a charger with Qualcomm's Quick Charge s...
by MarkTF
Fri Oct 11, 2019 2:53 pm
Forum: General discussion
Topic: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?
Replies: 10
Views: 370

Re: Will Quick Charge 3.0 provide consistent power to Raspberry Pi 4B?

I've used something similar to this to power multiple single board computers. Per the specifications it should have plenty of capacity, and, coming from a reputable brand, it probably more or less meets the stated specifications. That said, unless you find someone who has used that particular device...
by MarkTF
Thu Aug 22, 2019 8:22 pm
Forum: Off topic discussion
Topic: Best Raspberry Pi Alternatives 2019
Replies: 62
Views: 5247

Re: Best Raspberry Pi Alternatives 2019

I'm not sure if CHIP is a good example. They were either very naïve or intentionally fraudulent. Either way, they're gone. I wonder if my Pocket CHIP even works still? Even at the time I couldn't understand the business model by which NextThing CHIP ever figured to turn a profit, but I don't think ...
by MarkTF
Thu Aug 22, 2019 7:58 pm
Forum: Off topic discussion
Topic: Best Raspberry Pi Alternatives 2019
Replies: 62
Views: 5247

Re: Best Raspberry Pi Alternatives 2019

. . . Beagle Board is a great system, but trying to figure it out as a “noob” is annoying compared to the ease of using a Pi. . . . I don't get this statement. The BeagleBone stuff is down on raw horsepower and the core chip is more oriented to embedded control applications which limits its market,...
by MarkTF
Tue Jul 30, 2019 2:25 pm
Forum: General discussion
Topic: Raspberry pi for coding on machine level?
Replies: 31
Views: 1495

Re: Raspberry pi for coding on machine level?

Would you recommend coding for the Raspberry Pi, on a machine code level? I realize that machine code is very device specific. And since the Pi has been created in the millions (probably sold more than any PC, phone, or even Mac), the highest chance to learn how to work with machine code, is to do ...
by MarkTF
Tue Jul 23, 2019 4:30 pm
Forum: General discussion
Topic: do spectrum analyzer with arduino due and raspberry pi
Replies: 3
Views: 249

Re: do spectrum analyzer with arduino due and raspberry pi

Olgac wrote:
Tue Jul 23, 2019 1:17 pm
"float object cannot be interpreted as an integer"
Something that is supposed to be an integer type is a float type. Probably num/downsample.
by MarkTF
Wed Jun 05, 2019 8:51 pm
Forum: General discussion
Topic: Python code is being executed slowly on Pi 3 B+
Replies: 14
Views: 718

Re: Python code is being executed slowly on Pi 3 B+

Any help will be appreciated. I'd start by getting rid of passing results via global variables and explicitly return those values from each function definition. I suspect you might be generating some large arrays in the function calls that aren't actually used, but it's very hard to follow the prog...
by MarkTF
Thu May 16, 2019 12:43 pm
Forum: General discussion
Topic: RPi for button presser
Replies: 19
Views: 960

Re: RPi for button presser

. . . I am using 5V push pull Solenoid. . . . New update in this. O have changed my mosfet with logic level mosfet. The circuit got worked. But the solenoid heated up so badly. What should i do to my circuit if want to give 12V external supply? The obvious solution would be to use a solenoid rated ...
by MarkTF
Fri May 10, 2019 9:34 pm
Forum: General discussion
Topic: How to flash using Raspberry Pi 3
Replies: 7
Views: 595

Re: How to flash using Raspberry Pi 3

The open source "stm8flash" utility builds and runs on RaspberryPi, so flashing the STM8 via USB/STLink/SWIM is possible. The official STM8 development tools are all Windows, but "SDCC" supports STM8. If one wants to use the STM libraries, they'll have to be modified to be compatible with SDCC. Ther...
by MarkTF
Wed May 01, 2019 6:33 pm
Forum: General discussion
Topic: Automomous Pi - battery duration?
Replies: 2
Views: 206

Re: Automomous Pi - battery duration?

If one were to take the requirement "a battery which lasts as long as possible" literally, one might look at the largest capacity battery in existence. Unless it's been superseded this is the Hornsdale Power Reserve in Australia(1) at 129 MegaWatt Hours capacity. Ignoring a lot of real world issues ...
by MarkTF
Mon Apr 29, 2019 3:02 pm
Forum: General discussion
Topic: Problem with range of 433 Mhz receiver
Replies: 8
Views: 532

Re: Problem with range of 433 Mhz receiver

Signal levels are so weak, and the "modulation method" so simple, that even if 0.001% of a PI generated signal will overwhelm the receiver if its too close. It will simply "see" the 433MHz signal all the time. A "better receiver", (meaning more sensitive) will therefore not help. This isn't quite r...
by MarkTF
Mon Apr 15, 2019 12:08 am
Forum: General discussion
Topic: Retired old android smartphone's (HELP PLEASE)
Replies: 11
Views: 789

Re: Retired old android smartphone's (HELP PLEASE)

I've a stack of old Android phones. Some have been rooted to run the Linux on Android app and used as mini-file servers. I've used them for time-lapse photography via readily available apps from the playstore. Programmed via AppInventor for special purposes such as a bluetooth terminal, home tempera...
by MarkTF
Thu Apr 11, 2019 1:31 pm
Forum: General discussion
Topic: Run a pi3 on battery for a week ?
Replies: 7
Views: 528

Re: Run a pi3 on battery for a week ?

1) Measure or estimate the average power consumption of your system in Watts. You need to provide this many Watts for 7x24 hours so multiply to get 1 week power consumption in units of Watt hours. This link provides some guidance: https://www.pidramble.com/wiki/benchmarks/power-consumption . As an e...
by MarkTF
Sun Apr 07, 2019 1:00 pm
Forum: General discussion
Topic: Raspberry Pi 2 RS232 Wireless transmitter
Replies: 2
Views: 311

Re: Raspberry Pi 2 RS232 Wireless transmitter

The Raspberry Pi 2 doesn't have integral Bluetooth; the Pi Zero W and various Pi 3 models do. With those, certainly it would be possible to do what you suggest. A better solution might be to use a dedicated Bluetooth to serial device such as the ubiquitous HC-05. https://components101.com/wireless/h...
by MarkTF
Fri Mar 29, 2019 8:09 pm
Forum: General discussion
Topic: Measuring strength of vibration on SW-420 shock sensor using Python/Raspberry Pi.
Replies: 6
Views: 580

Re: Measuring strength of vibration on SW-420 shock sensor using Python/Raspberry Pi.

Yea I've been searching the web for a little while now and appears that it isn't possible to produce values on the Raspberry Pi like you can for the Arduino but instead just high and low like you said. I was just hoping this wasn't the case and someone knew how to do it. :( The second sketch in you...
by MarkTF
Fri Mar 29, 2019 3:10 pm
Forum: General discussion
Topic: Measuring Pi power with a Keweisi USB tester
Replies: 3
Views: 245

Re: Measuring Pi power with a Keweisi USB tester

These things work by measuring the voltage drop across a small value series resistor (current sense resistor) in line with the ground side of USB power. As a design decision one wants the voltage drop across this resistor at the maximum current (maybe 3 Amps) to be relatively small so that the volta...
by MarkTF
Fri Mar 29, 2019 2:19 pm
Forum: General discussion
Topic: How long will it stay on with a external battery?
Replies: 33
Views: 1405

Re: How long will it stay on with a external battery?

Thank you so much for all the help! :?: No one has actually given you an answer. The calculated example is exactly that - a mathematical answer and is worth the paper it’s written on (no disrespect meant). The calculated example(s) tell one the necessary parameters and the procedure to find the ans...
by MarkTF
Thu Mar 28, 2019 3:29 pm
Forum: General discussion
Topic: How long will it stay on with a external battery?
Replies: 33
Views: 1405

Re: How long will it stay on with a external battery?

20100 / 500 = 40.2 hours You're assuming this battery outputs 5V. If it doesn't, your trivial calculation is clear, simple and wrong. OP: We need more detail, like: 1: Do you really mean battery, or do you mean powerbank? 2: If battery, what chemistry and what voltage (or how many cells)? 3: Is it ...
by MarkTF
Thu Mar 28, 2019 3:07 pm
Forum: General discussion
Topic: Multiple Pi's to replace W10
Replies: 40
Views: 2496

Re: Multiple Pi's to replace W10

Hi All Still very dissatisfied with MS W10 (I sometimes wonder who owns my laptop!) I've found Linux, in it's differing forms, very difficult to master but Rpi I can manage. I wonder if it's possible to run multiple Pi's? It's possible to run a cluster with multiple RPis, but one would have to "mas...
by MarkTF
Wed Mar 27, 2019 7:42 pm
Forum: General discussion
Topic: Sterilization of Pi
Replies: 27
Views: 1650

Re: Sterilization of Pi

Sterilization methods and impact on electronics in medical devices: https://www.eetimes.com/document.asp?doc_id=1278906#
by MarkTF
Mon Mar 25, 2019 2:37 pm
Forum: General discussion
Topic: Two way pi to pi communication module
Replies: 2
Views: 177

Re: Two way pi to pi communication module

I thought about using LoRa, however it uses 1 way communication . . . LoRa modules are generally transceivers, that is they can either transmit a message or receive a message at a particular instant in time. Typically in a network one wants only one device at a time to be transmitting, but they can...
by MarkTF
Thu Mar 14, 2019 1:25 pm
Forum: General discussion
Topic: Stroboscope Guitar Tuner With RPi-Controlled LEDs
Replies: 7
Views: 686

Re: Stroboscope Guitar Tuner With RPi-Controlled LEDs

I hadn't known about this sort of tuner prior to your posting and now you've got me motivated to try to build up one of these. I've just placed an order for 1 Watt LEDs and have sketched out some drive circuit ideas to try out. When (if?) I get around to building something I'll post an update. I'll ...
by MarkTF
Wed Mar 13, 2019 1:56 pm
Forum: General discussion
Topic: USB Gadget mode; am I connected?
Replies: 20
Views: 1237

Re: USB Gadget mode; am I connected?

The device connection should be registered in dmesg. From the RPi command line dmesg | tail will show the most recent activity so doing this after connecting should give information about the attempt to connect and whether it was successful. Like all things Linux one can script around this to period...
by MarkTF
Tue Mar 12, 2019 2:17 am
Forum: General discussion
Topic: Stroboscope Guitar Tuner With RPi-Controlled LEDs
Replies: 7
Views: 686

Re: Stroboscope Guitar Tuner With RPi-Controlled LEDs

Generating this signal is pretty trivial with the pigpio library using the hardware PWM. Frequency accuracy would be equivalent to the processor crystal (something like 50 parts per million) plus the discrete tune frequency step error which is also small at these frequencies. As an example in Python...

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