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by Douglas6
Wed Dec 18, 2013 11:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Abel Electronics WiringPi
Replies: 1
Views: 1343

Re: Abel Electronics WiringPi

Since nobody knowledgeable has answered yet, I'll throw in two cents. 1.) You only need to do the setup once, outside of the loop. You might want to put a time.delay(250) after, just to be sure it's settled down. 2.) It looks like (from Gordon's examples) that analogRead() returns an int, not a floa...
by Douglas6
Wed Dec 18, 2013 10:01 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP3424 ADC potentiometer value
Replies: 11
Views: 5220

Re: MCP3424 ADC potentiometer value

Having taken a breeze thru the Wikipedia article on resistor ladders http://en.wikipedia.org/wiki/Resistor_ladder , I'm even more intrigued. Could you explain more about your resistor ladder? Was that an original part, a new IC, or something you built with discrete resistors? Wikipedia seems to say ...
by Douglas6
Wed Dec 18, 2013 8:49 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: MCP3424 ADC potentiometer value
Replies: 11
Views: 5220

Re: MCP3424 ADC potentiometer value

Sounds like an interesting project, and an interesting problem. I haven't a clue, but I bet I could learn something from some of the folks here. (<- thinly disguised 'bump')
by Douglas6
Wed Dec 18, 2013 6:48 pm
Forum: Beginners
Topic: transform projects from LPC2148 to respberry pi
Replies: 4
Views: 1085

Re: transform projects from LPC2148 to respberry pi

I have no experience with the LPC2148, but the things you mentioned can easily be interfaced to the Pi, with the possible exception of the CAN controller (well, not 'easily') Take a look at this thread, you'll probably understand it better than I :) http://www.raspberrypi.org/phpBB3/viewtopic.php?f=...
by Douglas6
Wed Dec 18, 2013 6:35 pm
Forum: General discussion
Topic: Configuration of LIRC
Replies: 1
Views: 621

Re: Configuration of LIRC

If you're running Raspian, there is no need to build LIRC from source, you can apt-get install it. Good instructions are here:
http://alexba.in/blog/2013/01/06/settin ... spberrypi/
by Douglas6
Tue Dec 17, 2013 3:59 pm
Forum: Automation, sensing and robotics
Topic: Using Bluetooth to detect when I'm nearby
Replies: 7
Views: 14461

Re: Using Bluetooth to detect when I'm nearby

There's this Adafruit tutorial on making the Pi into an Ibeacon, but that's the other way 'round, and it seems to be Apple specific. http://learn.adafruit.com/pibeacon-ibeacon-with-a-raspberry-pi This idea is something I'm interested in as well, I'll add anything I find out here. Shouldn't be hard w...
by Douglas6
Mon Dec 16, 2013 4:45 pm
Forum: Troubleshooting
Topic: auto start
Replies: 8
Views: 1114

Re: auto start

Depending on the answer to RaTTuS's question (why?), you could 'shutdown' by polling a GPIO pin and performing a 'sudo halt', and bring it back up by grounding GPIO3. I'm doing that via an ATTiny85, but I spose it could be done with a 555 timer circuit as well. In this case, 'shutdown' is not the sa...
by Douglas6
Mon Dec 16, 2013 3:48 am
Forum: Networking and servers
Topic: Bluetooth Access Point
Replies: 56
Views: 43232

Re: Bluetooth Access Point

Thanks maxwed. These days, as of raspian 2013-09-25, dbus and gobject both seem to be included with python 2.7, but pand is deprecated at best. It's a moving target for sure.
by Douglas6
Sun Dec 15, 2013 5:55 pm
Forum: Troubleshooting
Topic: Bluetooth Dongle not detected by hcitool
Replies: 20
Views: 56217

Re: Bluetooth Dongle not detected by hcitool

Douglas8 I got promoted :) I'm shooting in the dark here (obviously), but you might try moving that entire directory away and rebooting. Maybe some cache is not happy with the new distro. DId Bluez get upgraded? dpkg --status bluez | grep '^Version:' Version: 4.99-2 I have to run out and do family ...
by Douglas6
Sun Dec 15, 2013 5:26 pm
Forum: Troubleshooting
Topic: Bluetooth Dongle not detected by hcitool
Replies: 20
Views: 56217

Re: Bluetooth Dongle not detected by hcitool

It does sound like a problem with the class. It might be interesting to see what's in your /var/lib/bluetooth/<xx:xx:xx:xx:xx:xx>/config file. Mine (working, also a CSR dongle) looks like this: cat /var/lib/bluetooth/00\:15\:83\:0C\:BF\:EB/config name raspberrypi-0 pairable yes class 0x420100 onmode...
by Douglas6
Sun Dec 15, 2013 5:04 pm
Forum: Troubleshooting
Topic: Bluetooth Dongle not detected by hcitool
Replies: 20
Views: 56217

Re: Bluetooth Dongle not detected by hcitool

Well, that would explain why it wasn't brought up automatically. I'll see if if I can reproduce the issue tonight. Are you running Raspian, and this occurred after an apt-get upgrade?
by Douglas6
Sun Dec 15, 2013 4:21 pm
Forum: Troubleshooting
Topic: Bluetooth Dongle not detected by hcitool
Replies: 20
Views: 56217

Re: Bluetooth Dongle not detected by hcitool

Normally the adapter is brought up at boot, but yours is down as shown by the hciconfig results. Do this:

Code: Select all

sudo hciconfig hci0 up
hcitool dev
and see if that persists a reboot. To make it discoverable:

Code: Select all

hciconfig hci0 piscan 
Or 'noscan' to make it undiscoverable.
by Douglas6
Fri Dec 13, 2013 7:25 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Too many switches, too low voltage?
Replies: 3
Views: 1142

Re: Too many switches, too low voltage?

"The maximum permitted current draw from the 3.3 V pins is 50 mA."
http://elinux.org/RPi_Low-level_peripherals#Power_pins
by Douglas6
Fri Dec 13, 2013 3:13 pm
Forum: Java
Topic: Real time GPIO monitoring with Pi4J [SOLVED: use pigpio]
Replies: 8
Views: 10657

Re: Best way to achieve time precision on GPIO interrupts

Java, with its garbage collection, is probably particularly bad at this sort of thing.
by Douglas6
Fri Dec 13, 2013 2:58 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Level-shifters for the pi
Replies: 8
Views: 2630

Re: Level-shifters for the pi

The third method is to use a transistor buffer, such as the one shown on the right hand side of this image: https://tylerjones.me/wp-content/uploads//2012/11/npn-arduino-rpi-buffer.jpg And if I want to pull a pin low, do I just move (and replace Vcc) the RX pin to the collector? Keep both resistors?
by Douglas6
Fri Dec 13, 2013 5:16 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Pin Tester?
Replies: 10
Views: 24702

Re: GPIO Pin Tester?

Perfect. Easy-peasy, thanks!
by Douglas6
Thu Dec 12, 2013 9:10 pm
Forum: Networking and servers
Topic: Bluetooth Access Point
Replies: 56
Views: 43232

Re: Bluetooth Access Point

I'm sure that tutorial wasn't too complicated once you have the python-dbus working correctly. It's not really. Using wlan0 instead of eth0 is a bit different, and also when using Raspian, you'll need to 'sudo apt-get install bridge-utils' yourself. And here's another tip that would have saved me 3...
by Douglas6
Thu Dec 12, 2013 6:52 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Pin Tester?
Replies: 10
Views: 24702

Re: GPIO Pin Tester?

Thanks everybody! @Dougie, thanks for the pointer to the wiringPi pintest script; that looks like the easiest way to test GPIO inputs. For outputs, it looks like I need to take some measurements. Just to be clear, if the multimeter reads 3.3V-ish, I can be confident that the output driver is un-comp...
by Douglas6
Thu Dec 12, 2013 4:53 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO Pin Tester?
Replies: 10
Views: 24702

GPIO Pin Tester?

My IR transmitter circuit (home-built, self-designed) has stopped working reliably, and I'm afraid I've singed a pin. My only surprise is that I've not managed to fry an entire Pi with my electronic stumbling about. My question involves the best way to test the GPIO pins to try and find any damaged ...
by Douglas6
Wed Dec 11, 2013 9:58 pm
Forum: Beginners
Topic: IP Address
Replies: 2
Views: 556

Re: IP Address

XBMC will show the IP address on the System | System info | Summary tab.
by Douglas6
Wed Dec 11, 2013 2:46 am
Forum: Python
Topic: run a function every x min
Replies: 21
Views: 7686

Re: run a function every x min

Check your indentation on the two lines after # restart the timer. Python is very picky about indentation. You're starting the timer twice, and never restarting it.

Then the program enters your infinite loop where it does nothing.
by Douglas6
Tue Dec 10, 2013 2:42 am
Forum: Networking and servers
Topic: Bluetooth Access Point
Replies: 56
Views: 43232

Re: Bluetooth Access Point

After catching a second wind and attacking this again, I think I licked it. In fact I'm typing this on my phone, connected via Bluetooth to a Raspberry Pi access point connected via WiFi to my router and out over the internet. It's a bit of an awkward process but it works.Gonna see if I can automate...
by Douglas6
Mon Dec 09, 2013 9:36 pm
Forum: Off topic discussion
Topic: 8-bit pranks
Replies: 5
Views: 3853

Re: 8-bit pranks

In High School (late '70s), I managed to hack into the HP 2000/Access time sharing system we used, and wrote a system-level program that required a password for log on. I still remember the password I hard-coded in: "ennui". Unfortunately, my program converted user input to uppercase before comparin...
by Douglas6
Mon Dec 09, 2013 1:05 pm
Forum: Off topic discussion
Topic: Good music to write code?
Replies: 14
Views: 5182

Re: Good music to write code?

I read somewhere that listening to music occupies a creative part of the brain that could otherwise be spent on solving coding problems.

The study did not include the effects of spouses.

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