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by frisbone
Mon Sep 07, 2015 8:08 pm
Forum: Troubleshooting
Topic: Strange ISR issues
Replies: 2
Views: 508

Re: Strange ISR issues

Turns out it was some strange wiringPi issue. I thought I had the latest version of it but as it turns out my version was built just a few days before the latest version was released.

The March 2013 version of the library does not exhibit this behavior.
by frisbone
Mon Sep 07, 2015 11:48 am
Forum: Troubleshooting
Topic: Strange ISR issues
Replies: 2
Views: 508

Re: Strange ISR issues

bump
by frisbone
Sun Sep 06, 2015 11:44 pm
Forum: Troubleshooting
Topic: Strange ISR issues
Replies: 2
Views: 508

Strange ISR issues

For those of you that have used Gordon's wiringPi library I have a question related to odd behavior. I am interfacing with an IMU which I set its interrupt pin to trigger (until read) at 50 hz. I verify this on my o-scope. I have tried the following on two different gpio pins (4 & 7 - rev B board). ...
by frisbone
Fri Feb 06, 2015 10:24 pm
Forum: Raspbian
Topic: How to disable iptables?
Replies: 14
Views: 66084

Re: How to disable iptables?

Hard to say what the source is as it was part of RaspBmc - I've been assuming its been built on top of Raspbian but this is what uname gives me: [email protected]:~$ uname -a Linux raspbmc 3.12.21 #2 PREEMPT Wed Jun 11 04:53:06 UTC 2014 armv6l GNU/Linux Turns out I was able to solve my problem without turn...
by frisbone
Fri Feb 06, 2015 5:34 pm
Forum: Raspbian
Topic: How to disable iptables?
Replies: 14
Views: 66084

Re: How to disable iptables?

This is what I get: [email protected]:~$ sudo iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT all -- 192.168.0.0/24 anywhere DROP all -- anywhere anywhere Chain FORWARD (policy ACCEPT) target prot opt source destina...
by frisbone
Fri Feb 06, 2015 5:11 pm
Forum: Raspbian
Topic: How to disable iptables?
Replies: 14
Views: 66084

Re: How to disable iptables?

Hmm, so when I type "iptables -L" and it returns something and I do lsmod and I see it, it doesn't mean its installed? Anyway to know for certain?
by frisbone
Fri Feb 06, 2015 4:39 pm
Forum: Raspbian
Topic: How to disable iptables?
Replies: 14
Views: 66084

How to disable iptables?

Anyone know how to disable the firewall (iptables) on raspbian?

Using lsmod I know its in my kernal but it doesn't show up as a service and I can't seem to use chkconfig.

I want to rule out that it is interfering with something else but I don't know how to shut it off. Please advise.
by frisbone
Fri Aug 30, 2013 3:13 pm
Forum: General discussion
Topic: USB and HDMI power usage
Replies: 3
Views: 1879

Re: USB and HDMI power usage

Thanks for the link - but I'm not sure what in there answers my questions. The blog post is about current draw on the USB port when it is actively connected to something. I'm more interested in draw when nothing is connected - likewise withe Ethernet (have Rev B board) and HDMI.
by frisbone
Fri Aug 30, 2013 2:24 pm
Forum: General discussion
Topic: USB and HDMI power usage
Replies: 3
Views: 1879

USB and HDMI power usage

If no USB devices are connected and no HDMI cable hooked up, is there still power usage on behalf of these two systems going on? I'm trying to decide if I need to disable them through software and/or hardware to minimize power usage while running on batteries. Also curious about the Ethernet port - ...
by frisbone
Fri Apr 05, 2013 10:17 am
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Three things: 1. You aren't allocating memory for your return buffer - you just declared a pointer - who knows where its pointing. ==> char buf[read_len]; instead of char *buf 2. You are printing out the pointer to the buffer and not the contents of the buffer: *buf, buf 3. Make sure 0x1d is your sl...
by frisbone
Wed Apr 03, 2013 12:01 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

John, Whether its perl or python they all still use a broadcom library that can be modified to support a solution for this board. The python library for I2C needs to be modified to add a modified read operation to support a "repeated start" using 10 bit addressing as is outlined earlier. If all of t...
by frisbone
Wed Apr 03, 2013 10:45 am
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

See my post earlier. I am having no problems at all now with wallasey's upgrade to the BCM library which he uses in his perl package. I attached a perl script that shows that it works. I have also been reading/writing just fine linking with just the "C" library. As he says - if you use the 10 bit ad...
by frisbone
Tue Mar 19, 2013 2:52 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Well I'm appreciative of your effort but regretful that my comment caused it. :lol:

Nothing against Perl - I just plan to use C for my project for a variety of reasons.
by frisbone
Sun Mar 17, 2013 10:53 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Thanks wallasey. I was able to install the perl package you referenced and can indeed get an answer to my WHOAMI register query now. For everyone else, I've attached my test perl script. If you aren't familiar with perl - just type "perl am_test.pl 13" in whatever directory you stored it. I get back...
by frisbone
Sat Mar 16, 2013 3:26 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Very disappointed that my RPi is the cause. I hate wasting money even if it is only $14. Maybe one day I'll use it on a real Microcontroller in an arduino environment. How does the ADXL345 compare to the MMA8452Q? Finally got my I2C lines on a scope by the time you all diagnosed it. Here is my pic o...
by frisbone
Thu Mar 14, 2013 11:21 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Look at this last post on the SparkFun site by Joeisi : https://forum.sparkfun.com/viewtopic.php?f=32&t=31340 Not sure if that applies to RPi users using the 3.3V off of the RPi. But then again I'm not smart enough to determine if the RPi schematic creates a similar similar situation necessitating a...
by frisbone
Thu Mar 14, 2013 7:51 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Yeah, I noticed that mistake (I think anyway) - following advice from the following link: https://projects.drogon.net/raspberry-pi/wiringpi/i2c-library/ Guess it was just a typo - but still doesn't have an effect when you correct it to i2c. I've seen another example program for Arduino now with a da...
by frisbone
Thu Mar 14, 2013 7:29 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Same issue as everyone else - WHO AM I register returns 0 Out of curiosity - did anyone notice that the example program (arduino) shows a data rate set of 115200? I'm using the wiringPi library and it has a data rate set capability: gpio load spi [rate] - but its in Kbps. I do wonder if we have to b...
by frisbone
Wed Mar 13, 2013 12:15 pm
Forum: Automation, sensing and robotics
Topic: Help with MMA8452Q over I²C
Replies: 47
Views: 10136

Re: Help with MMA8452Q over I²C

Did you have success with this? I am doing this very soon myself with the same board with a Rev2 RPi. Would love to learn from your mistakes ;)

Could you post some pics of your connectivity and links to software setup, etc? If you are still having issues perhaps we could collaborate.

Ian
by frisbone
Mon Mar 11, 2013 1:52 pm
Forum: Beginners
Topic: 3 AA's at 4.5V
Replies: 5
Views: 2385

Re: 3 AA's at 4.5V

The I/O will only be logic input and I2C bus. No need for USB or Ethernet. Starting with only HDMI it seems almost functional except for frequent resets - which I'm assuming is being caused by HDMI drain. Just hoping someone has seen the power profile of the RP when used only as an embedded device (...
by frisbone
Sun Mar 10, 2013 9:50 pm
Forum: Beginners
Topic: 3 AA's at 4.5V
Replies: 5
Views: 2385

3 AA's at 4.5V

Hi, I'm getting started on a project in which the PI will only be used for interfacing with two I2C devices and some GPIO. No HDMI, no USB. Anyone know if 4.5V will be sufficient for this purpose and if so any guesses on how long it could power the board? I realize there are better solutions but thi...

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