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by John Public
Mon Nov 25, 2019 5:49 pm
Forum: General discussion
Topic: I'd like to buy two RasberryPi 3+. Most place have it out of stock
Replies: 7
Views: 647

I'd like to buy two RasberryPi 3+. Most place have it out of stock

I'd like to buy two RasberryPi 3+ (europe). Most place have it out of stock.
by John Public
Fri Nov 09, 2018 10:06 am
Forum: Troubleshooting
Topic: hc-12 and Raspberry Zero - not getting /dev/ttyS0
Replies: 0
Views: 200

hc-12 and Raspberry Zero - not getting /dev/ttyS0

I am trying to test HC-12 on a Raspberry Zero. I am following the example at http://dev.drun.net/2017/05/10/reading-hc-12-from-rpi-and-sending-to-domoticz/ I've connected wires as in the picture there and then test if /dev/ttyS0 is available. It is not. I tested both 3.3V and 5V pins on RPi Zero. I ...
by John Public
Fri May 11, 2018 7:32 pm
Forum: Troubleshooting
Topic: Monitor not showing anything
Replies: 2
Views: 343

Re: Monitor not showing anything

Thanks for the reply. I managed to get the setting back to normal this way:
- I hard-shutdown rpi (pulled the power cord)
- took the SD card to another Windows computer and edited the config.txt to a better value.
It started OK with no data loss, Whew!
by John Public
Fri May 11, 2018 6:59 pm
Forum: Troubleshooting
Topic: Monitor not showing anything
Replies: 2
Views: 343

Monitor not showing anything

I have a Samsung LE23R86BC which according to specs can handle 1368x768 So I edited /boot/config.txt to have hdmi_group=2 hdmi_mode=39 Now when I boot RPi my monitor says "Mode not supported" and a blank screen. However, the lights blinking on RPi indicate that it has booted. Is there a ke...
by John Public
Mon May 07, 2018 7:27 am
Forum: HATs and other add-ons
Topic: 5v relay board and Raspberry zero
Replies: 6
Views: 5284

Re: 5v relay board and Raspberry zero

I went ahead and tried with my setup (the one without a transistor). It worked OK - no problems. Most of the time it is turning using the relay ON a 12v connected to a electric strike door lock. When a suitable code is entered it turns the relay off for a few seconds.
by John Public
Sun May 06, 2018 10:00 am
Forum: HATs and other add-ons
Topic: 5v relay board and Raspberry zero
Replies: 6
Views: 5284

Re: 5v relay board and Raspberry zero

Would this be OK? Connect RPi0 5v to the relay unit or should I connect 3.3V to VCC instead?
I don't want my zero to fry. The 4V7 is a Zener 4.7V
by John Public
Sun May 06, 2018 7:16 am
Forum: HATs and other add-ons
Topic: 5v relay board and Raspberry zero
Replies: 6
Views: 5284

5v relay board and Raspberry zero

I have gotten info on how to use a 5v Relay module with raspberry Pi from https://www.raspberrypi.org/forums/viewtopic.php?t=197339 It says that I should use transistor 2n2222 and a resistor r470 as follows. Image4.jpg Unfortunately I don't have 2n2222 but instead have only BC546B. I am using the se...
by John Public
Thu Apr 05, 2018 2:20 pm
Forum: Troubleshooting
Topic: Two new RPI3 ' won't boot at all
Replies: 6
Views: 750

Re: Two new RPI3 ' won't boot at all

OK! Answering myself. It appears that rasbian servers were down or unavailable since after some waiting all upgrades and downloads succeeded.
by John Public
Thu Apr 05, 2018 1:27 pm
Forum: Troubleshooting
Topic: Two new RPI3 ' won't boot at all
Replies: 6
Views: 750

Re: Two new RPI3 ' won't boot at all

I've got the problem solved. The new RPI does not seem to support previous linux distros. The new "stretch" distro is recognised. I was able to to install it. But another problem rises: I installed the Raspbian Stretch Lite and proceeded to install a Gui to it as described on: https://die-...
by John Public
Thu Apr 05, 2018 10:09 am
Forum: Troubleshooting
Topic: Two new RPI3 ' won't boot at all
Replies: 6
Views: 750

Two new RPI3 ' won't boot at all

I bought two new Raspberry Pi 3 model B+ from Pimoroni last week. I formatted a new SD card and turned power on. The red light blinks but the green light not. The HDMI shows only a color palette on the monitor (and one "lightning" sign). No boot up sequence ever comes up. The same thing ha...
by John Public
Thu Mar 22, 2018 8:21 am
Forum: General discussion
Topic: Having trouble setting GPIO high
Replies: 8
Views: 995

Re: Having trouble setting GPIO high

I am a bit confused. Dropping all pinMode(nnn,i) -functions appeared to fix everything. What is the point of having them if it is more consistent to just read and write and forget about modes? Is there some caveats? Is there a way to check whether a pin is "read"-mode or "write"-...
by John Public
Wed Mar 21, 2018 5:26 pm
Forum: General discussion
Topic: Having trouble setting GPIO high
Replies: 8
Views: 995

Having trouble setting GPIO high

My i5 is set to the physical pin 40 (GPIO29 or WiringPi pin #29). I have Raspberry Zero and I'd like to set it to high. I have nothing connected to the pin. For some reason the following code odes not work as I'd expect: printf("set to%d HIGH\n",i5); pinMode(i5,OUTPUT); digitalWrite(i5,HIG...
by John Public
Sun Mar 11, 2018 8:38 pm
Forum: General discussion
Topic: WiringPi in commercial projects?
Replies: 1
Views: 513

WiringPi in commercial projects?

I could not find info about using WiringPi in commercial projects. If I create a new executable from my C source files but have WiringPi functions in it what needs to be done permission-wise? I see a lot of projects with wiring pi functions included.
by John Public
Sat Feb 03, 2018 11:25 am
Forum: Advanced users
Topic: Reset Raspberry Pi from Arduino
Replies: 24
Views: 7391

Re: Reset Raspberry Pi from Arduino

I need a hard reset when system has locked up and needs a power down & power up.
With that in mind what wires from Arduino shoul go to the run pins?
by John Public
Sat Feb 03, 2018 7:19 am
Forum: Advanced users
Topic: Reset Raspberry Pi from Arduino
Replies: 24
Views: 7391

Re: Reset Raspberry Pi from Arduino

Assuming that I have set the voltage to 3.3v in the Arduino what should I connect to the two "run" pins on the Raspberry. The "run" connection are rectangel and round -versions?
by John Public
Fri Feb 02, 2018 4:27 pm
Forum: Advanced users
Topic: Reset Raspberry Pi from Arduino
Replies: 24
Views: 7391

Re: Reset Raspberry Pi from Arduino

I've Arduino Pro Mini (5V) version. I'd like to use one of the available pin of Arduino to hard reset Raspberry.
What would be most conevenient way to do it from Arduino? I have a bunch of resistors and leds I could use.
by John Public
Mon Sep 11, 2017 12:36 pm
Forum: Camera board
Topic: Turn night-time camera (noir-camera) camera to daylight camera
Replies: 10
Views: 11383

Re: Turn night-time camera (noir-camera) camera to daylight camera

The camera that I bough from Aliexpress has its lens screwed on. I removed it and as far as I can see the lens does not have a filter. The lens part is clear and hollow. The flat sensor does not have a filter. I just see the minuscule sensor element and if it had a filter it would have to be glued o...
by John Public
Tue Sep 05, 2017 4:57 pm
Forum: Camera board
Topic: Turn night-time camera (noir-camera) camera to daylight camera
Replies: 10
Views: 11383

Re: Turn night-time camera (noir-camera) camera to daylight camera

The camera module I have is same as this: https://www.aliexpress.com/item/Pi-camera-module-Raspberry-Pi-2-model-B-B-Plus-lens-Focal-length-5-million-pixel/32421623838.html?ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10068_5380020_10171_10326_10084_10083_10080_10304_10307_10082_10081_...
by John Public
Tue Sep 05, 2017 11:31 am
Forum: Camera board
Topic: Turn night-time camera (noir-camera) camera to daylight camera
Replies: 10
Views: 11383

Turn night-time camera (noir-camera) camera to daylight camera

Is there a way to Turn night-time camera (noir-camera) camera to daylight camera. Is there same raspistill option or other setup setting I could get is to work like a daylight camera? I've taken off the ir-lamps.
by John Public
Thu Aug 24, 2017 5:18 am
Forum: General programming discussion
Topic: Read remote JPG and stream as MJPEG from the pi
Replies: 1
Views: 1543

Re: Read remote JPG and stream as MJPEG from the pi

Have you checked the "Camera board"? There's a lot of info on your subject, for example: viewtopic.php?f=43&t=63276
by John Public
Wed Aug 23, 2017 7:36 pm
Forum: General programming discussion
Topic: Arduino -like "Serial plotter" (visual datalogger)
Replies: 0
Views: 959

Arduino -like "Serial plotter" (visual datalogger)

Arduino has visual datalogger called "Serial plotter" which is simple to use. Is there any similar and easy to use for Raspberry /Linux.
by John Public
Thu Aug 03, 2017 6:26 pm
Forum: Bare metal, Assembly language
Topic: Protection GPIO pins
Replies: 6
Views: 2434

Re: Protection GPIO pins

With a simple 2K resistor in the between like this:

Rpi3 (sender) GPIO (physical pin 32) -------->2K------>Rpi3 (receiver) GPIO (physical pin 32)

Just to bring down the voltage? Can you explain how that help (I'm a noob)
by John Public
Thu Aug 03, 2017 11:34 am
Forum: Bare metal, Assembly language
Topic: Protection GPIO pins
Replies: 6
Views: 2434

Protection GPIO pins

I am connecting from GPIO12 from one RPi3 (sender) to another RPi3's GPIO12 (receiver). Then I'm sending data by setting (bitbanging) the sender's GPIO high or low. So the sender has GPIO 12 as "output" and the rerceiver as "input". I've got just a straight wire and everything wo...
by John Public
Tue Aug 01, 2017 6:28 pm
Forum: Troubleshooting
Topic: Power RPi3 from GPIO pins?
Replies: 4
Views: 1443

Re: Power RPi3 from GPIO pins?

After inspection with powerfull magnifiers it appears that a black "thingy" next to where the microusb is connected appears burn out. So I powered it via 5V pin 2 and ground and lo and behold! it works again. I just love these SBCs!
by John Public
Sun Jul 09, 2017 11:54 am
Forum: General discussion
Topic: step-up regulator, buck converter 5V->3.3V
Replies: 12
Views: 2885

Re: step-up regulator, buck converter 5V->3.3V

When I used the "regular" receiver that noise was far less, an occasional beep evry 10 secs or so. The superhet on other hand is just a constant stream of noise, ups and downs.
What about the amperage from a step down?

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