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by Killertechno
Tue Jun 04, 2019 10:02 am
Forum: General discussion
Topic: PCB Design Software and Small Qty Manufacturing
Replies: 10
Views: 1783

Re: PCB Design Software and Small Qty Manufacturing

Let's talk about small quantity PCB manufacturing (other discussion about PCBway has closed, I don't understand why, maybe a duck closed discussion....). I designed small PCB to be used with Raspberry Zero, I just need 1 PCB as prototype. I usually send my gerbers to Eurocircuits (or PCBproto), for ...
by Killertechno
Tue Jun 04, 2019 7:34 am
Forum: HATs and other add-ons
Topic: Pi Zero Enc28j60 Network Adapter Module
Replies: 4
Views: 294

Re: Pi Zero Enc28j60 Network Adapter Module

I was able to use exactly those cheap Arduino modules with Pi Zero three years ago, see the instruction links: https://www.raspberrypi.org/forums/viewtopic.php?t=152965#p1015300 I already follower those instructions, that's why, due not working, I moved to another board. Without creating new discus...
by Killertechno
Fri May 31, 2019 5:38 pm
Forum: Compute Module
Topic: Guidelines for USB bus design for CM
Replies: 1
Views: 135

Guidelines for USB bus design for CM

Hi to all! I'm designing board using Raspberry CM. I need USB devices such pendrive, USB to serial (I need several serial ports), wireless card.... I found USB hub chip and all devices are USB 2.0; all devices has gor own USB power switch. I don't need to plug/unplug them, they are all fixed to main...
by Killertechno
Wed Apr 24, 2019 1:29 pm
Forum: Python
Topic: Get filter kernel from output signal?
Replies: 1
Views: 100

Get filter kernel from output signal?

Hi to all, I was taking a look to this convolution example: import numpy as np import scipy.signal import matplotlib import matplotlib.pyplot as plt import sys matplotlib.use('TkAgg') # test convolve kernel = [0.5, 0.45, 0.05, 0] input_signal = [0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, ...
by Killertechno
Tue Apr 23, 2019 12:58 pm
Forum: Automation, sensing and robotics
Topic: FYI: controlling Lights from Google Calendar via Raspi
Replies: 2
Views: 5578

Re: FYI: controlling Lights from Google Calendar via Raspi

Nice job, just one question: must I use google calendar?
I mean, I need to update calendar through web interface (I want run Pi headless), but if not available internet connection?
Are there similar calendars available?
Thanks.
by Killertechno
Fri Apr 19, 2019 1:36 pm
Forum: Device Tree
Topic: USB to serial adapter: ttyUSBx identification?
Replies: 2
Views: 410

USB to serial adapter: ttyUSBx identification?

Hi to all, I donìt know if this is correct section.... I'm using several devices with serial to USB bridge, so I have ttyUSB0, ttyUSB1, ttyUSB2, ttyUSB3, up to 8 ttyUSBx entries. Here dmesg log: [178399.675164] usbcore: registered new interface driver pl2303 [178399.675250] usbserial: USB Serial sup...
by Killertechno
Tue Apr 09, 2019 4:44 pm
Forum: HATs and other add-ons
Topic: Pi Zero Enc28j60 Network Adapter Module
Replies: 4
Views: 294

Re: Pi Zero Enc28j60 Network Adapter Module

I was searching for ENC28J60 network adapter, I bought a ENC28J60 network adapter made for Arduino, it didn't work, so I bought a new one specific for Zero (but correctly working also on Pi 2B). Ok, this board is more expensive than Arduino one (I paid about 18 euro on Amazon), but I haven't wasted...
by Killertechno
Tue Apr 09, 2019 4:41 pm
Forum: HATs and other add-ons
Topic: Pi Zero Enc28j60 Network Adapter Module
Replies: 4
Views: 294

Pi Zero Enc28j60 Network Adapter Module

I was searching for ENC28J60 network adapter, I bought a ENC28J60 network adapter made for Arduino, it didn't work, so I bought a new one specific for Zero (but correctly working also on Pi 2B). Ok, this board is more expensive than Arduino one (I paid about 18 euro on Amazon), but I haven't wasted ...
by Killertechno
Thu Apr 04, 2019 2:51 pm
Forum: General programming discussion
Topic: How disable system time update?
Replies: 5
Views: 622

Re: How disable system time update?

sudo systemctl stop systemd-timesyncd
sudo systemctl disable systemd-timesyncd

Still getting time updated when internet available....
by Killertechno
Thu Apr 04, 2019 10:19 am
Forum: General programming discussion
Topic: How disable system time update?
Replies: 5
Views: 622

Re: How disable system time update?

Unless my math is out (and it could be) that chip could loose 3 minutes a year depending on temp. I would be interested to know how you get on with it :) Yes, maximum drift would be 63 seconds (within 0 to 40 °C), or 110 seconds (-40 to 85 °C) after 1 year (365 days). I check sync alignment with GP...
by Killertechno
Wed Apr 03, 2019 11:18 pm
Forum: General programming discussion
Topic: How disable system time update?
Replies: 5
Views: 622

How disable system time update?

Hi to all, I'm making tests using DS3231 RTC and GPS receiver. At boot I write into DS3231 date from GPS receiver (starting at 1 Jan 2000), but when accessing to Raspberry through ssh I can see system time and RTC time are updated to 2019. Disabling internet access on router I can correctly find RTC...
by Killertechno
Tue Apr 02, 2019 10:52 am
Forum: Compute Module
Topic: CM3 vertical socket
Replies: 15
Views: 8107

Re: CM3 vertical socket

I don't know if any news...
I found this from JST website (UK), why not make a buy group?
DM-7D4-H2500
Uk users could then sell It to other european users...
by Killertechno
Thu Mar 28, 2019 1:53 pm
Forum: C/C++
Topic: [TCP] Server/client non blocking: missing sys/event.h?
Replies: 1
Views: 1313

[TCP] Server/client non blocking: missing sys/event.h?

Hi guys, I need to write C program for TCP server (TCP to serial bridge RFC 2217). First step would be creating TCP server; I'm a noob about TCP server programming so I've found online TCP server examples: https://github.com/mafintosh/echo-servers.c/blob/master/unix-non-blocking-echo-server.c But wh...
by Killertechno
Tue Mar 26, 2019 3:54 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Newbie with RN2483 (LoRa)
Replies: 0
Views: 110

Newbie with RN2483 (LoRa)

Hi to all, I shame very much to ask this but I can't understand how LoRa works.... I bought a couple of RN2483 modules. I can set frequency, band, and so on, and I can correctly make transmission point-to-point using "mac pause" disabling LoRaWAN. 1) When I send packet, is it send broadcast to all d...
by Killertechno
Wed Feb 13, 2019 9:12 am
Forum: C/C++
Topic: [C] compatibility data types 32-64 bit?
Replies: 18
Views: 1160

[C] compatibility data types 32-64 bit?

Hi to all, I have little doubt about compatibility between 32/64 bit OSs..... C data types size in bytes (e.g. for long) could be different, so I should tell compiler to compile in 32bit even if running on 64bit OS. If I've correctly understood, I just need to use "-m32" option in compiler string. O...
by Killertechno
Mon Jan 21, 2019 4:56 pm
Forum: C/C++
Topic: License key for C program?
Replies: 1
Views: 372

License key for C program?

Hi to all,
I'm writing software in C for specific Raspberry HAT: I want software could work only with specific HAT (with specific unique hardware ID).
Is this possible in C?
I have no idea about doing this, it's first time...
Thanks.
by Killertechno
Fri Dec 28, 2018 11:57 pm
Forum: C/C++
Topic: Little doubt on floating point precision
Replies: 7
Views: 763

Re: Little doubt on floating point precision

This not working: #include <stdio.h> #define hpf_filterorder 1 // ordine del filtro passa-alto per la rimozione dell'offset #define max_components 1 #define filter_order hpf_filterorder struct FilterBuffer { float input[filter_order+1]; float output[filter_order+1]; }; struct FilterBuffer FilterValu...
by Killertechno
Fri Dec 28, 2018 11:27 pm
Forum: C/C++
Topic: Little doubt on floating point precision
Replies: 7
Views: 763

Re: Little doubt on floating point precision

Sorry, taking a look to Python code "a" is not an integer as I supposed but iy says <type 'numpy.ndarray'>.
by Killertechno
Fri Dec 28, 2018 11:14 pm
Forum: C/C++
Topic: Little doubt on floating point precision
Replies: 7
Views: 763

Re: Little doubt on floating point precision

Here another example code: #include <ctype.h> #include <errno.h> #include <fcntl.h> #include <dirent.h> #include <libgen.h> #include <math.h> #include <netinet/in.h> #include <sys/stat.h> #include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/stat.h> #include <s...
by Killertechno
Fri Dec 28, 2018 9:54 pm
Forum: C/C++
Topic: Little doubt on floating point precision
Replies: 7
Views: 763

Little doubt on floating point precision

Hi to all, I'm porting Python code to C code and I have alittle doubt. On my Python code I have: a = 18781 b = 0.997649 c = a*b print("%f" % (c)) result is 18736.851729 while in C code: int a = 18781; float b = 0.997649; double c = 0.997649; printf("%f\r\n", a*b); printf("%f\r\n", (float)(a)*b); pri...
by Killertechno
Fri Dec 21, 2018 7:18 pm
Forum: Other programming languages
Topic: [newbie] How install npm?
Replies: 2
Views: 1891

[newbie] How install npm?

Hi to all, I know this cuold be a stupid question but I'm totally noob about this.... I have a server I can supply seismic data (Raspberry at 127.0.0.1), I want display realtime data on webpage following this example: http://www.seis.sc.edu/~crotwell/seisplotjs_demo/realtime/seedlink.html My target ...
by Killertechno
Thu Dec 20, 2018 11:25 am
Forum: C/C++
Topic: math problems in C
Replies: 12
Views: 2943

Re: math problems in C

Hi to all, not same trouble but I'm porting program from python too.... #define Gauss_sigma 0.025 #define Gauss_wiLength 2.0 #define SPS 100 double dT; unsigned int Gauss_smplLen; int main (void) { dT = 1.0/(double)SPS; // quanto di campionamento printf("Lunghezza finestra filtro %f campioni (double...
by Killertechno
Sun Dec 09, 2018 6:34 pm
Forum: Beginners
Topic: How to set time and date in boot time
Replies: 25
Views: 5273

Re: How to set time and date in boot time

Hi guys, may I ask where raspberry does save date at poweroff? I mean, where does raspberry read date after boot? I'm using latest raspbian, I set /etc/fake-hwclock.data file with dummy time (1th Jan 2000) and set it with read-only permissions. At boot I get time updated to 2016 without RTC and no n...
by Killertechno
Mon Dec 03, 2018 5:50 pm
Forum: Python
Topic: Run external command and get output
Replies: 1
Views: 659

Run external command and get output

Hi to all, I am a noob in python and I need to run shell scripts. I've found some examples: #!/usr/bin/python import subprocess, sys cmd = "sudo /etc/init.d/ntp stop" p = subprocess.Popen(cmd, shell=True, stderr=subprocess.PIPE) ## Talk with date command i.e. read data from stdout and stderr. Store ...
by Killertechno
Mon Dec 03, 2018 3:30 pm
Forum: Python
Topic: Periodically update DS3231 RTC with NTP
Replies: 11
Views: 1263

Re: Periodically update DS3231 RTC with NTP

Hi to all, I found this thread so I try to resume my old project due I'm confused about ntp sync and RTC on Raspberry pi..... I'm using one of latest Raspberry images (April or August 2018, I don't remember). In my application I use DS3231 (I need its PPS for external hardware) and I need to detect ...

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