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by scotty101
Tue Oct 23, 2018 4:14 pm
Forum: Beginners
Topic: Increase current capability of 3.3v PWM
Replies: 2
Views: 50

Re: Increase current capability of 3.3v PWM

b4tn wrote:
Tue Oct 23, 2018 3:14 pm
Is it as simple as just using a transistor on the output with a separate 3.3 volt power supply? I am not sure how this would affect the PWM signal.
Yep. Drive a transistor from a GPIO pin and use a more powerful 3.3v supply.
Won't have any effect on the PWM signal.
by scotty101
Tue Oct 23, 2018 9:52 am
Forum: General discussion
Topic: Setting up gpio using classes
Replies: 4
Views: 119

Re: Setting up gpio using classes

With gpiozero, when you configure a new pin you create an instance of one of gpiozero's classes. If I had two devices that needed to use the same GPIO pins, I'd just pass the class a reference to a pin that has already been setup. For example (untested example code only) from gpiozero import OutputD...
by scotty101
Tue Oct 23, 2018 9:37 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: how w/r file to i2c memory
Replies: 3
Views: 72

Re: how w/r file to i2c memory

Files are just a series of bytes, why not just store each byte of the file to device. What exactly are you trying to do?
by scotty101
Tue Oct 23, 2018 9:31 am
Forum: General discussion
Topic: How to send data of SHT25 sensor from adafruit huzzah to raspberry pi
Replies: 1
Views: 51

Re: How to send data of SHT25 sensor from adafruit huzzah to raspberry pi

Given that the huzzah is just an ESP8266, I'd suggest using MQTT to send data to the Pi. I'd change the huzzah from being the access point to the Pi being the access point and the huzzah connects to the WiFi provided by the Pi. You'd the install an MQTT broker on the Pi. Much of this is explained on...
by scotty101
Tue Oct 23, 2018 9:23 am
Forum: Python
Topic: interfacing pulse sensor with pi-python
Replies: 1
Views: 38

Re: interfacing pulse sensor with pi-python

The tutorials for the MCP3008 should still be valid. The MCP3208 is just a higher precision version of the MCP3008 (12bit vs 10bit). The electrical connections will be the same.

Many libraries that allow reading from the MCP3008 will also support the MCP3208.
by scotty101
Tue Oct 23, 2018 9:17 am
Forum: Beginners
Topic: puzzled by LCD tft screens
Replies: 1
Views: 44

Re: puzzled by LCD tft screens

Most of these tuts stick the screen direct onto the 40 gpio pins, so it is awkward to use the remaining pins :( Many of the screens, specifically the Adafruit screens, break out the GPIO pins so that you can connect other devices to the unused pins. Also i want to develop via my desktop monitor, an...
by scotty101
Tue Oct 23, 2018 8:59 am
Forum: Python
Topic: 4-20mA Ouput
Replies: 1
Views: 36

Re: 4-20mA Ouput

Have you sought help from the manufacturer? They seem to have a lot of resources on their website even if they are a bit light for the 4-20mA and python examples (most of their code examples are in C). And they say they offer free support for their products. https://libstock.mikroe.com/projects/view...
by scotty101
Mon Oct 22, 2018 8:47 am
Forum: General discussion
Topic: Best way to commonly setup io
Replies: 3
Views: 156

Re: Best way to commonly setup io

It is impossible to tell you given that you haven't shared any detailed information about the type of sensors you are using. Ser clk & data will be used by almost everybody This seems to suggest that you will be using a sensor that connects via the SPI port. In this case, you don't mess around with ...
by scotty101
Sun Oct 21, 2018 5:07 pm
Forum: Beginners
Topic: Hello from the UK - utilising some old LCD's
Replies: 2
Views: 106

Re: Hello from the UK

Here is a good place to ask.

Just share some more information about your LCDs; model number, datasheet, link to where you bought them and someone may be able to help you
by scotty101
Sat Oct 20, 2018 11:59 pm
Forum: General discussion
Topic: Best way to commonly setup io
Replies: 3
Views: 156

Re: Best way to commonly setup io

Share some real code rather than jibberish.
by scotty101
Fri Oct 19, 2018 8:28 am
Forum: Advanced users
Topic: connect an 5V sensor in microusb port instead of gpio pins?
Replies: 3
Views: 124

Re: connect an 5V sensor in microusb port instead of gpio pins?

No. The sensor is not a USB device and the USB ports cannot act like GPIO pins. If you are dead set on connecting it to the USB port, you'll need a separate device to convert the signal from the sensor to something that the USB ports can understand. You could do this with a small Arduino clone or a ...
by scotty101
Thu Oct 18, 2018 4:03 pm
Forum: Assistive technology and accessibility
Topic: Communication device -- Help with touch sensor mpr121 Please!
Replies: 3
Views: 86

Re: Communication device -- Help with touch sensor mpr121 Please!

I've spent many hours trying different things... Trouble is, I'm a complete novice to writing code, I will keep looking at examples and trying to modify/merge things together to get something close. Thanks for sharing the info! Once you have something close, share it and the error messages that you...
by scotty101
Thu Oct 18, 2018 4:01 pm
Forum: Python
Topic: SEND DATA TO A SERVER AND POST IN DATABASE
Replies: 1
Views: 32

Re: SEND DATA TO A SERVER AND POST IN DATABASE

When you write code you have to consider what can go wrong. In this case you are sending data to via TCP to a server that isn't listening yet. You have to "catch" this error and do something. Usual schemes might be to re-try every few seconds until the message goes through and perhaps have a maximum...
by scotty101
Thu Oct 18, 2018 2:51 pm
Forum: Advanced users
Topic: Near Space Experiment using a Raspberry Pi 3
Replies: 2
Views: 114

Re: Near Space Experiment using a Raspberry Pi 3

Perhaps you can share your script(s) so that someone can help you join the two together.

Remember to use [code][/code] tags when you post your code.
by scotty101
Thu Oct 18, 2018 1:33 pm
Forum: Other projects
Topic: RF Transmitter
Replies: 2
Views: 129

Re: RF Transmitter

What range to you want the signal to cover?

There are various "add-ons" for the Pi to send RF signals. Some that operate in the 433MHz band for example
You may also want to investigation "LoRa" which is a RF protocol that works over relatively long range.
by scotty101
Thu Oct 18, 2018 1:30 pm
Forum: Assistive technology and accessibility
Topic: Communication device -- Help with touch sensor mpr121 Please!
Replies: 3
Views: 86

Re: Communication device -- Help with touch sensor mpr121 Please!

Have you read the Adafruit tutorial for the touch sensor https://learn.adafruit.com/mpr121-capacitive-touch-sensor-on-raspberry-pi-and-beaglebone-black/usage There is a section of code roughly half way down that page that give an example of how to read from the different buttons. I'd create a functi...
by scotty101
Thu Oct 18, 2018 10:06 am
Forum: Beginners
Topic: How to make a non-blocking delay on Tkinter?
Replies: 8
Views: 169

Re: How to make a non-blocking delay on Tkinter?

How have you confirmed that it doesn't get called? Try putting a print("Thread Running") at the start of the function. Also, you are aware that the function will only run once right? If you want it to keep running in the background, the thread should contain a while loop and potentially a time.sleep...
by scotty101
Thu Oct 18, 2018 10:03 am
Forum: Troubleshooting
Topic: RPI camera don't work with zBar
Replies: 3
Views: 111

Re: RPI camera don't work

Does this old topic help?
viewtopic.php?t=68247
or this one
viewtopic.php?t=204954
by scotty101
Wed Oct 17, 2018 12:39 pm
Forum: Beginners
Topic: How to make a non-blocking delay on Tkinter?
Replies: 8
Views: 169

Re: How to make a non-blocking delay on Tkinter?

I'd consider putting your GPIO button read calls in a separate function to the one that updates the display. Display function is called every "centi-second" but the GPIO function is called less frequently to debounce the button. The two communicate though a variable which is used to start/stop the t...
by scotty101
Wed Oct 17, 2018 12:19 pm
Forum: Beginners
Topic: How to make a non-blocking delay on Tkinter?
Replies: 8
Views: 169

Re: How to make a non-blocking delay on Tkinter?

Two methods. 1. Split up your code in to smaller functions which are called with the .after method. I'd use a function which acts as a state machine, it remembers what state it was in last time, performs the next action, sets which state it should move in to next and calls the .after method with an ...
by scotty101
Wed Oct 17, 2018 9:56 am
Forum: Python
Topic: Driving multiple stepper motors with Python
Replies: 13
Views: 359

Re: Driving multiple stepper motors with Python

What was wrong with the class method I share with you a while back? I appreciate what you've done to split the code across two modules but that isn't an effective way of doing this and serves no useful purpose. You have essentially the same code in two places rather than a common function that takes...
by scotty101
Wed Oct 17, 2018 9:10 am
Forum: General discussion
Topic: 8 channel CCTV with Pi 3 B
Replies: 8
Views: 200

Re: 8 channel CCTV with Pi 3 B

What type of cameras do you have? I suspect for 8 cameras, this would only be possible if they were network connected cameras (WiFi, ethernet).
I doubt the Pi could cope with reading the video signal from 8 USB or composite output cameras (requiring a USB device)
by scotty101
Wed Oct 17, 2018 8:58 am
Forum: Python
Topic: Variable passed to class
Replies: 9
Views: 225

Re: Variable passed to class

I'm not sure what you are trying to do so perhaps you can explain it again. Here is an example of a python class (and simple usage) that may help you figure out what you want to do or the correct syntax. class MyClass: def __init__(self, param1, param2, param3): self.param1 = param1 self.param2 = pa...
by scotty101
Wed Oct 17, 2018 8:52 am
Forum: Python
Topic: Driving multiple stepper motors with Python
Replies: 13
Views: 359

Re: Driving multiple stepper motors with Python

Can you share your entire code file? Odds are that you've got your GPIO pin mapping incorrect.
by scotty101
Wed Oct 17, 2018 8:46 am
Forum: Beginners
Topic: RTC module of raspberry pi 3
Replies: 1
Views: 62

Re: RTC module of raspberry pi 3

The raspberry pi does not have a Real Time Clock. You need to add an external one.

The time kept by the Pi is managed in software only.

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