Go to advanced search

by Anthony S
Sun Jun 23, 2019 8:25 pm
Forum: Beginners
Topic: PT100 & MAX31865 on a raspberry
Replies: 6
Views: 454

Re: PT100 & MAX31865 on a raspberry

One question I forgot to ask previously was - does your application absolutely demand a PT100 sensor? There are many types of digital temperature sensor - some of them quite accurate - which could interface fairly easily with the Pi (whose inputs are essentially digital in nature). Some of these sen...
by Anthony S
Sun Jun 23, 2019 5:43 pm
Forum: Beginners
Topic: PT100 & MAX31865 on a raspberry
Replies: 6
Views: 454

Re: PT100 & MAX31865 on a raspberry

To implement a 4-wire configuration using a PT100 RTD requires two main things: 1. A means of generating a precise constant current to generate a voltage across the sensor; 2. A means of converting the analog sensor voltage into a digital format that can be read by the Pi (i.e., an analog to digital...
by Anthony S
Mon Jun 17, 2019 4:44 pm
Forum: Beginners
Topic: Fans problem.
Replies: 5
Views: 245

Re: Fans problem.

Why do you want the fans to stay on all the time?
Are you concerned that the temperature control circuit isn't working properly?
One way to test it would be to increase the ambient temperature, perhaps by using a hairdryer blown at the case - but don't get it too hot!
Just an idea.

Cheers,

Tony.
by Anthony S
Thu Jun 06, 2019 6:26 pm
Forum: General discussion
Topic: detecting another pie ? Possible
Replies: 2
Views: 165

Re: detecting another pie ? Possible

Can you be more specific about your requirements?

For example, are you looking just for a kind of 'proximity' detection (i.e., one Pi is able to detect that another is nearby), or must they share some kind of communication link?

Tony.
by Anthony S
Thu Jun 06, 2019 6:21 pm
Forum: General discussion
Topic: New Raspberrypi short circuit repair
Replies: 10
Views: 573

Re: New Raspberrypi short circuit repair

Hi ujjwalrathod007,

Sorry to hear of your problems.

You may find the following post relevant and interesting:

viewtopic.php?t=240280

Cheers,

Tony
by Anthony S
Wed Jun 05, 2019 5:05 pm
Forum: Beginners
Topic: PWM
Replies: 4
Views: 166

Re: PWM

There are several ways to generate precise PWM signals using the Raspberry Pi, but Arduino?.........are you sure you're on the right forum?
by Anthony S
Fri May 31, 2019 11:34 am
Forum: Troubleshooting
Topic: Level shifter not working?
Replies: 8
Views: 307

Re: Level shifter not working?

Hi bluc, Do you have any optocouplers to hand? If you do, you could connect the optocoupler's input (the LED side) to your Pi via a series resistor, and the opto's output would drive the SSR (the opto's transistor collector would be connected to the SSR -ve terminal, the emitter would connect to the...
by Anthony S
Fri May 31, 2019 11:20 am
Forum: Beginners
Topic: First Project - Already stuck
Replies: 9
Views: 805

Re: First Project - Already stuck

@W. H. Heydt
I agree entirely.

Lindiml, if you could give us more info about your project, maybe we could help you more!

Tony.
by Anthony S
Thu May 30, 2019 11:42 am
Forum: Beginners
Topic: First Project - Already stuck
Replies: 9
Views: 805

Re: First Project - Already stuck

Hi LindimI, Is it absolutely essential that you must have two Pi 3 boards? If you could put your LED and your sensor together on the same board that would make life a lot easier for you. However, if you really must have two completely separate boards, then one way of communicating between them would...
by Anthony S
Thu May 23, 2019 4:06 pm
Forum: Beginners
Topic: Pi 3 Model B+ - not starting up
Replies: 10
Views: 505

Re: Pi 3 Model B+ - not starting up

Hi kentor21, It's quite possible that you may have shorted the 5V and 3.3V pins while your Pi was powered up. Apparently, that is almost always fatal since is causes irreparable damage to the main power management chip. If that is what has happened I am afraid there is nothing you can do about it bu...
by Anthony S
Thu May 23, 2019 3:58 pm
Forum: Python
Topic: 'active_state' parameter in Gpiozero (Solved)
Replies: 6
Views: 535

Re: 'active_state' parameter in Gpiozero

I've just received a response from Andrew Scheller via Github regarding the apparent anomalies with 'InputDevice'. The problem is down to the fact that I was using .wait_for_active() with the base InputDevice class, whereas (as Andrew has kindly clarified) that is only available with the DigitalInpu...
by Anthony S
Wed May 22, 2019 5:53 pm
Forum: Beginners
Topic: Pi 3 Model B+ - not starting up
Replies: 10
Views: 505

Re: Pi 3 Model B+

Hi kentor21, If the green LED does not flash at all this could certainly be symptomatic of software problems. However, it could also point to a hardware failure. Is it possible you could have shorted any of the pins on the 40-pin header? If you have access to a voltmeter, measure the voltage at pin ...
by Anthony S
Wed May 22, 2019 4:01 pm
Forum: Beginners
Topic: PT100 Temperature sensor
Replies: 3
Views: 150

Re: PT100 Temperature sensor

Hi Laundryjohn, Your PT100 will generate an analog voltage proportional to the device's resistance (and hence temperature) and the drive current. This analog signal cannot be connected directly to the Pi since the Pi's inputs are essentially digital in nature. You would need to connect your sensor t...
by Anthony S
Wed May 22, 2019 2:37 pm
Forum: General discussion
Topic: I need advice to not short circuit my Raspberry Pi 3 B+
Replies: 3
Views: 283

Re: I need advice to not short circuit my Raspberry Pi 3 B+

Hi musopark, Some general advice to protect your Pi: 1. At all costs avoid a short circuit between the 5V and 3.3V rails - this would almost certainly destroy your Pi - and be careful not to short either of those rails to ground (0V). 2. Make sure you have a good quality power supply. 3. If your 'fo...
by Anthony S
Wed May 22, 2019 2:19 pm
Forum: Python
Topic: 'active_state' parameter in Gpiozero (Solved)
Replies: 6
Views: 535

Re: 'active_state' parameter in Gpiozero

Hi B.Goode,

I agree entirely. Perhaps this forum is not quite the right place to pursue this problem, so I have raised an issue at Github.

I'll let you know if I get any response.

Thanks,
Tony.
by Anthony S
Wed May 22, 2019 12:17 pm
Forum: Python
Topic: 'active_state' parameter in Gpiozero (Solved)
Replies: 6
Views: 535

Re: 'active_state' parameter in Gpiozero

Hi Dougie, Many thanks for your suggestions. I can confirm that both python-gpiozero and python3-gpiozero are the latest versions (1.5.0). I have also recently run sudo update and sudo upgrade so I'm fairly confident everything else is up to scratch. Sadly, the problem with 'InputDevice' persists. H...
by Anthony S
Tue May 21, 2019 5:55 pm
Forum: Python
Topic: 'active_state' parameter in Gpiozero (Solved)
Replies: 6
Views: 535

'active_state' parameter in Gpiozero (Solved)

Hi to Everyone, I've been playing around with the different classes available in Gpiozero and I've created over thirty little programs to test the inputs and outputs. All worked fine with no problems at all. However, I get an unexpected error when using the 'active_state' parameter in the InputDevic...
by Anthony S
Fri May 17, 2019 3:05 pm
Forum: Troubleshooting
Topic: Can I use 5V to power a display with tm1637 and control it by 3 V
Replies: 6
Views: 265

Re: Can I use 5V to power a display with tm1637 and control it by 3 V

Hi luchiand, According to the TM1637 datasheet, the minimum high-level input voltage is specified as 0.7*VDD, i.e., 70% of the supply voltage. So with VDD = 5V, the device would recognise a minimum voltage level of 3.5V as a logic high - some 0.2V higher than the Pi's 3.3V logic high level, so it's ...
by Anthony S
Sun May 12, 2019 7:56 pm
Forum: Beginners
Topic: 3.3v pin shorted to 5v
Replies: 7
Views: 413

Re: 3.3v pin shorted to 5v

Hi Emdad,

Just in case you were considering replacing the MXL7704 converter chip, you may find the following post helpful:

https://www.raspberrypi.org/forums/vie ... ?t=240280

Cheers,

Tony
by Anthony S
Sun May 12, 2019 7:53 pm
Forum: Troubleshooting
Topic: Could I Change MXL7704 Chip with Soldering Machine
Replies: 15
Views: 862

Re: Could I Change MXL7704 Chip with Soldering Machine

Hi furkancoskun,

Just in case you're still considering replacing the MXL7704 converter chip, you may find the following post helpful:

https://www.raspberrypi.org/forums/vie ... ?t=240280

Cheers,

Tony
by Anthony S
Sat May 11, 2019 8:58 pm
Forum: Troubleshooting
Topic: Don't try this at home, kids!
Replies: 11
Views: 635

Re: Don't try this at home, kids!

wildfire wrote:
I beg to differ, the problem is as you stated in the earlier part of your post (above).
I beg to differ also. I'd say my shorting the 3.3V and 5V pins was the cause of the problem.
by Anthony S
Sat May 11, 2019 5:04 pm
Forum: Troubleshooting
Topic: Don't try this at home, kids!
Replies: 11
Views: 635

Don't try this at home, kids!

A quick browse around the forum reveals that I'm not the only one who's had the misfortune to short the 5V and 3V3 pins on the Pi's 40-pin header. In my case, this resulted in a very dead 3B+. Not merely resting. Not pining for the fjords. Deceased. Kaput. The problem lies with the MXL7704, a "Five ...
by Anthony S
Fri May 10, 2019 6:59 pm
Forum: Beginners
Topic: relay board and monitor
Replies: 9
Views: 264

Re: relay board and monitor

Hi doriamauro,

Can you provide more info about your intended LED? You mention 'optic fiber' at 0.5W - that's just 42mA at 12V which could easily be handled by a suitable transistor interface. As pcmanbob said, the relay board is probably a huge overkill for what you want to do.

Tony.
by Anthony S
Fri May 10, 2019 6:36 pm
Forum: Troubleshooting
Topic: I2C intermittent failure with BMP280 sensor
Replies: 7
Views: 335

Re: I2C intermittent failure with BMP280 sensor

Hi Pharsea, When you refer to the "BMP280 sensor module" do you mean just the Bosch pressure sensor on its own, or some kind of PCB module? Powering the BMP280 sensor directly from 5V could well cause damage since it's supply is only rated to an absolute maximum of 4.25V. On the other hand, if it's ...
by Anthony S
Tue May 07, 2019 10:30 pm
Forum: Troubleshooting
Topic: Raspberry Pi B+ - Help to replace micro SD socket and power LED
Replies: 18
Views: 659

Re: Raspberry Pi B+ - Help to replace micro SD socket and power LED

Looking at your photos it seems that the micro SD card socket made a fairly 'clean' break from the PCB. Do you still have the socket? What condition is it in? If it's not badly damaged you may be able to solder it back on to the PCB (of course, remove the card first!) If you can't find the red LED y...

Go to advanced search