Go to advanced search

by gordon77
Mon May 10, 2021 8:21 pm
Forum: Beginners
Topic: Can I connect a 12V relay to GPIO directly with separate power supply?
Replies: 14
Views: 350

Re: Can I connect a 12V relay to GPIO directly with separate power supply?

danjperron wrote:
Mon May 10, 2021 7:20 pm
Thanks Gordon.

I read it all , my first language is french, but nothing new.

Still no schematic.


Maybe I do have one like this. I'll check tonigh!
No schematic but good photos to try and work it out.
by gordon77
Mon May 10, 2021 7:03 pm
Forum: Beginners
Topic: Can I connect a 12V relay to GPIO directly with separate power supply?
Replies: 14
Views: 350

Re: Can I connect a 12V relay to GPIO directly with separate power supply?

I managed to find this info but no schematic..

https://skyduino.wordpress.com/2012/05/ ... -de-keyes/

It does look like the input goes through a resistor to the opto.
by gordon77
Sun May 09, 2021 1:16 pm
Forum: General discussion
Topic: Really lousy RPI quality and no factory QA
Replies: 41
Views: 1490

Re: Really lousy RPI quality and no factory QA

Thanks, it's great to know how they are tested. The OP didn't actually say they didn't work.
by gordon77
Sat May 08, 2021 1:14 pm
Forum: General discussion
Topic: Which pi is which
Replies: 40
Views: 1258

Re: Which pi is which

FREE pen with every Pi !! :D

What colour ?
by gordon77
Sat May 08, 2021 1:05 pm
Forum: General
Topic: pico micropython pwm freq
Replies: 10
Views: 254

Re: pico micropython pwm freq

Thanks. Where do I report the issue ?
by gordon77
Sat May 08, 2021 12:20 pm
Forum: General
Topic: pico micropython pwm freq
Replies: 10
Views: 254

Re: pico micropython pwm freq

Tabled figures measured with an oscilloscope, so pretty accurate.

Graph measured on input to pico and timed, so not as accurate.
by gordon77
Sat May 08, 2021 9:31 am
Forum: General
Topic: pico micropython pwm freq
Replies: 10
Views: 254

Re: pico micropython pwm freq

Thanks
by gordon77
Sat May 08, 2021 8:14 am
Forum: General
Topic: pico micropython pwm freq
Replies: 10
Views: 254

pico micropython pwm freq

Trying to get 6267Hz but get some strange results, any thoughts ?
by gordon77
Fri May 07, 2021 7:12 pm
Forum: Off topic discussion
Topic: What size screw driver for Philips and bolts do I need?
Replies: 37
Views: 1079

Re: What size screw driver for Philips and bolts do I need?

In this document https://www.emcstandards.co.uk/files/pc ... 1999_1.pdf it talks about keeping any holes, including mounting, away from noisy, dirty, high speed or especially sensitive EM zones.
by gordon77
Fri May 07, 2021 6:31 pm
Forum: HATs and other add-ons
Topic: Relay board appears to pull inputs high?
Replies: 6
Views: 176

Re: Relay board appears to pull inputs high?

That looks like my relay board. From the schematic I can see why I see the voltage on the wire. Is this a typical wiring for a relay and opto-isolator? Is there a reason it couldn't be wired up so the output of the GPIO pin turns on the opto-isolator? Can the GPIO sink more current than source? Tha...
by gordon77
Fri May 07, 2021 3:36 pm
Forum: General programming discussion
Topic: Pico pwm duty range
Replies: 6
Views: 192

Re: Pico pwm duty range

B.Goode wrote:
Fri May 07, 2021 11:16 am

Pedantically, isn't that for the Duty Cycle, not the Frequency?
Where did it say it was the frequency ?
by gordon77
Fri May 07, 2021 3:10 pm
Forum: HATs and other add-ons
Topic: Relay board appears to pull inputs high?
Replies: 6
Views: 176

Re: Relay board appears to pull inputs high?

I guess they are ensuring the input is not floating, which may bring on the led which could be confusing.
by gordon77
Fri May 07, 2021 10:42 am
Forum: General programming discussion
Topic: Pico pwm duty range
Replies: 6
Views: 192

Re: Pico pwm duty range

The generic uPython docs just say 'an integer'. https://docs.micropython.org/en/latest/library/machine.PWM.html?highlight=pwm Perhaps it should be raised as a Documentation Issue here: https://github.com/raspberrypilearning/getting-started-with-the-pico/issues/new Cheers, it also says "value i...
by gordon77
Fri May 07, 2021 8:16 am
Forum: General programming discussion
Topic: Pico pwm duty range
Replies: 6
Views: 192

Pico pwm duty range

Why does this example say the range is 0 to 65025 when 0 to 65535 appears to work ?

https://projects.raspberrypi.org/en/pro ... the-pico/7
by gordon77
Fri May 07, 2021 6:20 am
Forum: HATs and other add-ons
Topic: Relay board appears to pull inputs high?
Replies: 6
Views: 176

Re: Relay board appears to pull inputs high?

Can you provide details or photo of the board ?

This could be the schematic ?

https://www.waveshare.com/rpi-relay-board.htm
by gordon77
Fri May 07, 2021 5:59 am
Forum: General discussion
Topic: Which pi is which
Replies: 40
Views: 1258

Re: Which pi is which

neilgl wrote:
Thu May 06, 2021 10:40 pm
Er OP only ha a few pi4 so he can write 2 4 6 8 on them?
Only after they have worked out which is which ;)
by gordon77
Thu May 06, 2021 12:27 pm
Forum: General discussion
Topic: knots to km/h
Replies: 24
Views: 669

Re: knots to km/h

From your link ... Knots tied at a distance of 47 feet 3 inches (14.4018 m) from each other,
by gordon77
Thu May 06, 2021 12:20 pm
Forum: General
Topic: QWERTY keyboard/keypad for Pico
Replies: 25
Views: 757

Re: QWERTY keyboard/keypad for Pico

hippy wrote:
Thu May 06, 2021 11:39 am
lars_the_bear wrote:
Thu May 06, 2021 11:08 am
I thought it would be difficult to source a connector to plug the ZX81 keyboard into -- I don't even know what that type of connection is called.
"FPC" I believe but could be wrong.
Yes it's FFC (FPC)
by gordon77
Thu May 06, 2021 10:25 am
Forum: Camera board
Topic: Real world minimum focus distance for 6mm HQ lens
Replies: 7
Views: 263

Re: Real world minimum focus distance for 6mm HQ lens

You could try using a dof calculator eg https://www.cambridgeincolour.com/tutor ... ulator.htm

I think 1/2.3" is the nearest to the pi hq sensor.
by gordon77
Thu May 06, 2021 9:00 am
Forum: General discussion
Topic: Which pi is which
Replies: 40
Views: 1258

Re: Which pi is which

Sorry, not read every reply but... Neofetch can tell you which board you have etc. Just install it: sudo apt-get install --no-install-recommends neofetch Then run it: neofetch --off And: Host: Raspberry Pi 4 Model B Rev 1.1 Memory: 803MiB / 3550MiB I have the 4GB version. There's other ways, too. :...
by gordon77
Thu May 06, 2021 8:52 am
Forum: Beginners
Topic: saving image from camera - low quality
Replies: 6
Views: 151

Re: saving image from camera - low quality

Full resolution is camera.resolution = (2592,1944)

Whats the picture of ? size will depend on image as its jpg.

Is it a focus problem
by gordon77
Wed May 05, 2021 8:41 pm
Forum: Raspberry Pi OS
Topic: Not able to install Python anymore
Replies: 8
Views: 264

Re: Not able to install Python anymore

Doesn't lite come with python installed ?

Go to advanced search