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by Richard-TX
Thu Jan 15, 2015 5:52 pm
Forum: Off topic discussion
Topic: AS regards some of the novice questions we're getting....
Replies: 25
Views: 3031

Re: AS regards some of the novice questions we're getting...

Back in 1988, before all of the gatewayed stuff happened, many sites got usenet news and email via UUCP over dialup lines. Usenet was filled with some very interesting people due to the fact that it took a certain amount of experience just to be able to use rn() and access was limited because you ha...
by Richard-TX
Thu Jan 15, 2015 5:32 pm
Forum: Python
Topic: Using Cron to update a log file
Replies: 46
Views: 4124

Re: Using Cron to update a log file

if you are still having problems, please post your code (cron.py).
by Richard-TX
Thu Jan 15, 2015 5:28 pm
Forum: Python
Topic: Using Cron to update a log file
Replies: 46
Views: 4124

Re: Using Cron to update a log file

Hello Richard-Tx, I tried cron but got stuck with it too. My python script that needs to execute every minute is called 'cron.py' and is located in home/debian. As I was advised earlier I made my crontab -e file to look something like this : * * * * * /usr/bin/python try this: 2 * * * * /home/debia...
by Richard-TX
Thu Jan 15, 2015 1:54 pm
Forum: Troubleshooting
Topic: Python is barely usable on Raspbian
Replies: 31
Views: 6894

Re: Python is barely usable on Raspbian

Just to give you an idea of the speed of a Raspberry vs an older desktop vs a modern desktop, here are the compile times of the same software package on different hardware.

Raspberry pi ~1 hour 45 minutes
Beaglebone -~ 50 minutes
Dell 690 (3 Ghz quad core) ~6 minutes
new computer ~ 3 minutes.
by Richard-TX
Thu Jan 15, 2015 1:44 pm
Forum: Off topic discussion
Topic: AS regards some of the novice questions we're getting....
Replies: 25
Views: 3031

Re: AS regards some of the novice questions we're getting...

I must be old... Before usenet, I remember fidonet and Telefinder BBS networks. See: https://en.wikipedia.org/wiki/FidoNet https://en.wikipedia.org/wiki/TeleFinder and V23... I remember the noise pollution that occurred when Fidonet started being gatewayed into Usenet. What a waste of bandwidth tha...
by Richard-TX
Thu Jan 15, 2015 1:37 pm
Forum: Python
Topic: Using Cron to update a log file
Replies: 46
Views: 4124

Re: Using Cron to update a log file

Hello Richard-Tx, /bin/sh: 1: cron.py: not found[/code] I dont know why this happens since when i execute from my command window '/home/Debian/cron.py' my file executes without any trouble.. Do you have any suggestions? Namita. "/bin/sh: 1: cron.py: not found" says it all. Cron has no path so you h...
by Richard-TX
Thu Jan 15, 2015 1:33 pm
Forum: General discussion
Topic: How many analog input ports in B+
Replies: 6
Views: 4542

Re: How many analog input ports in B+

The Raspberry Pi isn't a Beaglebone Black.
by Richard-TX
Thu Jan 15, 2015 1:28 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Fixed I2C address - best solution for third sensor
Replies: 41
Views: 6039

Re: Fixed I2C address - best solution for third sensor

Ok Another question is there a way to change the address id of the chip with the 3 address pins and if so could i not hook 2 chips to the same rpi i2c input lines and just change the address in the script to access the different chips Yes. That is how I2C works. It is also how you get 128/256 GPIOs...
by Richard-TX
Thu Jan 15, 2015 1:16 pm
Forum: Python
Topic: Using Cron to update a log file
Replies: 46
Views: 4124

Re: Using Cron to update a log file

There are two things that cron scripts must have.
A PATH variable set
Be executable (mode 755)

if you can clear your PATH variable and be able to run you script as a regular user, it should run from cron.
by Richard-TX
Thu Jan 15, 2015 1:25 am
Forum: Troubleshooting
Topic: Sainsmart relays working backward
Replies: 5
Views: 1195

Re: Sainsmart relays working backward

The Sainsmart relays boards are a poor design for more than one reason. The reverse logic is one of them. The other reason iis and what I really hate about them is that the cheap surface mount LEDS age and then draw less and less current. Eventually the small amount of current passing through the LE...
by Richard-TX
Wed Jan 14, 2015 4:22 pm
Forum: General discussion
Topic: Can anyone suggest me a reliable relay board?
Replies: 31
Views: 5977

Re: Can anyone suggest me a reliable relay board?

visinet wrote:Richard;

I am interested in your boards and possibly your services to do a custom design for me. Would you be interested, and how may I contact you to get info on both.

Thanks

Jeff
A PM works as does email.
by Richard-TX
Wed Jan 14, 2015 4:16 pm
Forum: Beginners
Topic: uninstalling problem
Replies: 7
Views: 978

Re: uninstalling problem

here is what I do to get rid of some software I will never use.

apt-get remove --purge wolfram-engine
apt-get remove --purge oracle-java7-jdk
or on newer builds
apt-get remove --purge oracle-java8-jdk
by Richard-TX
Wed Jan 14, 2015 4:05 pm
Forum: Troubleshooting
Topic: Volume was not properly unmounted ...
Replies: 46
Views: 114139

Re: Volume was not properly unmounted ...

This is really just an annoyance issue. It does not affect performance in any way. You can safely ignore the message. It is what I do.
by Richard-TX
Wed Jan 14, 2015 3:59 pm
Forum: Automation, sensing and robotics
Topic: I2C and SPI at same time?
Replies: 8
Views: 4427

Re: I2C and SPI at same time?

I2C and SPI are on different pins and yes you can use both at the same time. I have done it myself.
by Richard-TX
Wed Jan 14, 2015 3:53 pm
Forum: Beginners
Topic: Pi with USB to Serial DB9 converter
Replies: 8
Views: 2597

Re: Pi with USB to Serial DB9 converter

Minor technical note.... There is no such thing as a "DB-9" connector. What you are thinking is a DE-9. (The others in the series are: DA-15, DB-25, DC-37, and DD-50.) Wikipedia says this. "DE-9 connector, a common type of D-subminiature electrical connector (often called DB-9)." DB9 is a common no...
by Richard-TX
Wed Jan 14, 2015 3:41 pm
Forum: Troubleshooting
Topic: Shutdown/reboot not working
Replies: 3
Views: 709

Re: Shutdown/reboot not working

what about init 0 or init 6?
by Richard-TX
Wed Jan 14, 2015 3:37 pm
Forum: Troubleshooting
Topic: sd card lifetime
Replies: 9
Views: 1557

Re: sd card lifetime

I use Toshiba cards. They have a 5 year warranty. If they fail within that 5 year period, I will just ship them back for a replacement.
by Richard-TX
Wed Jan 14, 2015 3:28 pm
Forum: Advanced users
Topic: How to make Raspbian read only?
Replies: 32
Views: 57077

Re: How to make Raspbian read only?

munklefish wrote:I strongly suggest good quality SD cards. I never shutdown my pi properly, i just pull the plug and Ive never had a corruption issue.
Same here. I have been unplugging my pis daily for over a year without issue.
by Richard-TX
Tue Jan 13, 2015 4:22 pm
Forum: Troubleshooting
Topic: Shut down
Replies: 3
Views: 569

Re: Shut down

Code: Select all

init 0
works for me
by Richard-TX
Tue Jan 13, 2015 4:15 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Fixed I2C address - best solution for third sensor
Replies: 41
Views: 6039

Re: Fixed I2C address - best solution for third sensor

All of the I2C chips I use are happy with +3 volt levels on the SDA and SCL lines regardless of being powered by +5 volts. While driving SDA/SCL lines when the chip is powered from +5 volts is outside the published specs, I have yet to find a chip that does not work under those conditions. In case y...
by Richard-TX
Tue Jan 13, 2015 3:58 pm
Forum: Other programming languages
Topic: Lazarus and MCP23017 I/O expander
Replies: 10
Views: 3260

Re: Lazarus - expander MCP23017

It appears that everything is there for you.

http://wiki.lazarus.freepascal.org/Laza ... hell_calls
by Richard-TX
Tue Jan 13, 2015 3:55 pm
Forum: C/C++
Topic: I2C c++ PCA9685 servo control issue
Replies: 9
Views: 9822

Re: I2C c++ PCA9685 servo control issue

Here is a smaller bit of code to move a servo connected to a PCA9685 #!/usr/bin/python print "This will move the second servo plugged into the controller" from Adafruit_PWM_Servo_Driver import PWM import time motornum=1 time.sleep(1.5) # ==============================================================...
by Richard-TX
Tue Jan 13, 2015 3:47 pm
Forum: General discussion
Topic: Serial data logging in pi into separate files
Replies: 8
Views: 2384

Re: Serial data logging in pi into separate files

One of the mechanisms that should take care of the many issues regarding logging and logfiles is the "logger" command. Syslog files are rotated automatically so cleanup suddenly becomes a non-issue. In most cases, having multiple log files based on data type is architecturally wrong. Having a reason...
by Richard-TX
Tue Jan 13, 2015 3:31 pm
Forum: C/C++
Topic: I2C c++ PCA9685 servo control issue
Replies: 9
Views: 9822

Re: I2C c++ PCA9685 servo control issue

... It is hard to beat 4096 steps of resolution. ... The Pi easily beats 4096 steps of resolution. pigpio at its default setting is slightly worse for servos. Controlling 64 or more servos or leds with pigpio is a little tough. I typically control 64 or more PWM channels on a single Pi using multip...
by Richard-TX
Tue Jan 13, 2015 3:10 pm
Forum: C/C++
Topic: I2C c++ PCA9685 servo control issue
Replies: 9
Views: 9822

Re: I2C c++ PCA9685 servo control issue

Need to use C/C++ or LUA, Python is not small enough. Thank you! I am not sure what you mean by that. The most you have to add to a default Raspbian distribution is the Python SMBus package which adds 88k. Now if you remove python, that will save 658k or a little over 1/2 a meg. LUA adds 256k to Ra...

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