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by pootle
Wed Jan 15, 2020 11:02 am
Forum: General discussion
Topic: Control board for a central heating style pump with dutycycle control
Replies: 11
Views: 382

Re: Control board for a central heating style pump with dutycycle control

Is that full variable speed, or a number of set speeds? IIRC the Grundfos pump on my heating system just has three speed settings, probably using different combinations of coils on the motor so not something that can be controlled externally. The pump does have 3 preset speeds, but the controller a...
by pootle
Wed Jan 15, 2020 8:36 am
Forum: Python
Topic: HELP WITH Two stepper motors at same time
Replies: 3
Views: 141

Re: HELP WITH Two stepper motors at same time

it's hard to follow your code when all the indentation is lost, You're starting in the right place with threading though. Can you post the code with indentation present.....?
by pootle
Wed Jan 15, 2020 8:31 am
Forum: General discussion
Topic: Control board for a central heating style pump with dutycycle control
Replies: 11
Views: 382

Re: Control board for a central heating style pump with dutycycle control

Most motors don't work with electronic dimmers, as "speed control" devices, so no "duty-cycle control" other than a few seconds on/off is possible. I'm specifically interested in central heating pump type motors (Grundfos etc), Don't care about most motors. I have a control unit on 1 that does cont...
by pootle
Mon Jan 13, 2020 12:08 pm
Forum: General discussion
Topic: Control board for a central heating style pump with dutycycle control
Replies: 11
Views: 382

Control board for a central heating style pump with dutycycle control

I want to control a standard mains central heating type pump from a Raspberry pi, with some basic control of speed. Presumably something with opto isolator in it, or driven with an rf signal Most of the stuff I've found uses relays (really? relays still?) like this one , which would clearly not work...
by pootle
Sun Jan 05, 2020 1:28 pm
Forum: General discussion
Topic: pi4, picamera 64 bit os and darknet - yolov3 is it possible?
Replies: 0
Views: 78

pi4, picamera 64 bit os and darknet - yolov3 is it possible?

Any way to get raspberry pi camera running on ubuntu server 64 on a raspberry pi? I've setup ubuntu server 64bit on a pi4, and starting from the info jbeale (and others) put in this thread , I have darknet - nnpack running well using both the tiny and standard models. In a separate universe I setup ...
by pootle
Sat Jan 04, 2020 2:00 pm
Forum: General discussion
Topic: Image recognition - what 4GB of memory can do
Replies: 55
Views: 3320

Re: Image recognition - what 4GB of memory can do

OOh! need to get the pi camera working too.....
by pootle
Sat Jan 04, 2020 1:59 pm
Forum: General discussion
Topic: Image recognition - what 4GB of memory can do
Replies: 55
Views: 3320

Re: Image recognition - what 4GB of memory can do

Cracking info, have built this on ubuntu 64 bit for pi and installed both standard and tiny, both working. Small mammal recognition seems to be a bit dodgy though! Just about to try streaming multiple images through it, rather than 1 shoting it.
20200102_125843pred.jpg
20200102_125843pred.jpg (236.34 KiB) Viewed 98 times
by pootle
Sat Jan 04, 2020 8:18 am
Forum: Automation, sensing and robotics
Topic: Stepper motor RPM using A4988 and pi 4
Replies: 2
Views: 169

Re: Stepper motor RPM using A4988 and pi 4

Why not try the code posted in response to your earlier question?
by pootle
Fri Jan 03, 2020 9:19 am
Forum: Python
Topic: td6600 driver and nema 17 stepper RPM
Replies: 2
Views: 142

Re: td6600 driver and nema 17 stepper RPM

A td6600 controller is not a good choice for a pi as you will need to level convert the control signals, much better to use (for a basic stepper controller like this) one of the A4988 family which use the same logic levels as the pi, so can be driven directly from gpio pins. Also these controllers a...
by pootle
Wed Jan 01, 2020 10:04 am
Forum: Python
Topic: Stepper motor RPM
Replies: 2
Views: 178

Re: Stepper motor RPM

This adafruit hat is not very good at driving steppers, I tested it in some detail, the info is here , but in summary (assuming their base code is still as it was then). standard adafruit library maxes out at around 80 steps per second. If your motor is 1.8 degrees per step this is about 25 rpm with...
by pootle
Fri Dec 20, 2019 9:39 am
Forum: Python
Topic: How to speed up measurement up to 100 value per second in spi interface,
Replies: 1
Views: 115

Re: How to speed up measurement up to 100 value per second in spi interface,

Can you clock the board to run faster?
Is the code optimized to make best use of the available spi bandwidth?
What is the current utilisation level of the spi bus?
What is the current measurement rate you can get?

Provide lots more information and we may be able to help better.
by pootle
Wed Oct 30, 2019 9:21 am
Forum: General discussion
Topic: How to install docker on raspberrypi effectively
Replies: 1
Views: 378

Re: How to install docker on raspberrypi effectively

Much easier to use something like this - especially if you want nodered and similar stuff.

or this if you want straight docker. ( I did have to reboot after install before it all worked on this one.)
by pootle
Tue Oct 22, 2019 10:13 am
Forum: General discussion
Topic: Pi Wifi IP messed up
Replies: 8
Views: 500

Re: Pi Wifi IP messed up

post the output from ifconfig.....
by pootle
Fri Oct 18, 2019 7:25 am
Forum: Automation, sensing and robotics
Topic: Open API Light Fixtures
Replies: 1
Views: 892

Re: Open API Light Fixtures

Not directly open API, but phillips hue (expensive) and Ikea TRÅDFRI (much cheaper) although closed systems are based on zigbee and this video describes a way to get at them directly.
by pootle
Wed Oct 16, 2019 6:53 am
Forum: Automation, sensing and robotics
Topic: pigpio capabilities?
Replies: 10
Views: 2190

Re: pigpio capabilities?

Yesterday I did try to control 4 servos from a Pi (powered by constant voltage power supply with 5V/2A). Although I used pigpio command to change the gripper servo only, after some time all servos go crazy for some time. What can be an explanation for that? The servos themselves generate a lot of n...
by pootle
Thu Sep 19, 2019 6:41 am
Forum: Automation, sensing and robotics
Topic: 2 Stepper Motors; Independent control
Replies: 9
Views: 1567

Re: 2 Stepper Motors; Independent control

Would all of the TMC drivers be able to run motors autonomously after settings configuration & function with commands as simple as go to "stepX"? All of the ones in that family - 5130, 5160 etc, I would expect to run pretty simply: Check at position zero clear crash flag repeat 111 times: set goto ...
by pootle
Wed Sep 18, 2019 7:34 am
Forum: Automation, sensing and robotics
Topic: 2 Stepper Motors; Independent control
Replies: 9
Views: 1567

Re: 2 Stepper Motors; Independent control

For driving stepper motors, a raspbery pi is every bit as capable as an arduino, either by offloading the low level driving to external chips, or by using dma control of the I/O pins providing very highly accurate timings. The standard Hat's available are not in general suitable for smart driving of...
by pootle
Tue Sep 17, 2019 7:01 am
Forum: General discussion
Topic: Python 2 or Python 3 ...?
Replies: 8
Views: 621

Re: Python 2 or Python 3 ...?

mattmiller wrote:
Mon Sep 16, 2019 8:16 am

Because of lot of us are dinosaurs and we'll still be using Python 2 until the heat death of the universe :)
I will stop using Python2 just as soon as the prophet Zarquon turns up
by pootle
Mon Sep 09, 2019 8:19 am
Forum: Automation, sensing and robotics
Topic: [SOLVED] How To Get Smooth PWM Control
Replies: 15
Views: 958

Re: [ASK] How To Get Smooth PWM Control

As I read the code, you aren't changing the throttle setting at all in the test, yet the drive motor speeds up and slows down. Is this true? Also I note you are going round the control loop at a hell of a rate - 2,500 times per second. I'm wondering if this is causing a problem somewhere downstream....
by pootle
Fri Sep 06, 2019 7:15 am
Forum: Automation, sensing and robotics
Topic: [SOLVED] How To Get Smooth PWM Control
Replies: 15
Views: 958

Re: [ASK] How To Get Smooth PWM Control

I had twitchy servos on a 2 servo project, it turned out that the servos themselves needed decoupling capacitors on the power feed right beside the servos themselves. The voltage spikes caused by servo motors starting and stopping were de-stabilizing the servo's own electronics. Try a moderate elect...
by pootle
Fri Sep 06, 2019 6:52 am
Forum: Python
Topic: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+
Replies: 6
Views: 376

Re: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+

Just been looking at the adafruit code on github, They have a specific example for fast read here.

It looks like the single shot approach you have programmed only works for relatively slow sample rates.

You need to use their fast read example as the base for you program.
by pootle
Fri Sep 06, 2019 6:20 am
Forum: Python
Topic: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+
Replies: 6
Views: 376

Re: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+

I'm not clairvoyant, this doersn't make sense. You could try going back to the example code from adafruit, checking it runs at the right speed, and then modifying that 1 step at a time to get the behaviour you want
by pootle
Wed Sep 04, 2019 6:39 am
Forum: Python
Topic: DBUS? permissions problem on Raspbian lite vs raspbian (runing bluedot)
Replies: 0
Views: 128

DBUS? permissions problem on Raspbian lite vs raspbian (runing bluedot)

I've got a strange (well to me at least) problem running a bluedot app on raspbian (buster). On gui versions of raspbian I can run the app with no problems either from an ssh session or from a terminal in the gui. On raspbian lite I get a permissions fail unless I run the command with sudo. I don't ...
by pootle
Tue Sep 03, 2019 1:44 pm
Forum: Python
Topic: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+
Replies: 6
Views: 376

Re: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+

Try without the print statement and see how fast it goes, if that speeds it up, then you need to print from a separate thread - or possibly a separate process.
by pootle
Tue Sep 03, 2019 7:28 am
Forum: Python
Topic: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+
Replies: 6
Views: 376

Re: Not able to make anywhere near 860 samples using ADS1115 on RPi3B+

This code reads 200 samples per second????

The sleep commands it goes through for a single read appear to add up to 4 seconds.

Assuming you really mean to use a larger array, just remove the print statement and see what difference it makes.

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