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by jbuehl
Wed Jun 12, 2019 5:46 pm
Forum: Other projects
Topic: Carputer Pi 3
Replies: 28
Views: 26399

Re: Carputer Pi 3

I don't think the DC-DC converters you have chosen are going to do what you want them to and might cause problems. I have heard that type of converter can have voltage spikes when they start up. The one I am using https://www.amazon.com/dp/B07H6YZ9XS should be able to provide enough power to run all...
by jbuehl
Wed Jun 05, 2019 3:48 pm
Forum: Other projects
Topic: Carputer Pi 3
Replies: 28
Views: 26399

Re: Carputer Pi 3

I just have the 12v input of the voltage converter wired to the red wire that is switched on and off and the 5v output directly connected to the RaspberryPi power connector. There's no conditioning or switching logic. I haven't had any issues from just switching the power on and off like that. The c...
by jbuehl
Tue May 21, 2019 4:50 pm
Forum: Other projects
Topic: Carputer Pi 3
Replies: 28
Views: 26399

Re: Carputer Pi 3

Here is a description of my carputer https://github.com/jbuehl/carputer. I gave up on trying to implement things like music or navigation and bought a commercial unit for that. I'll be improving the documentation in the near future.
by jbuehl
Wed Oct 19, 2016 10:36 pm
Forum: Troubleshooting
Topic: Pi as A2DP sink - SBC decoding error; audio completely stops
Replies: 3
Views: 2037

Re: Pi as A2DP sink - SBC decoding error; audio completely s

Contrary to what I posted earlier, the problem continued to occur for me even when I was not in range of wifi. I gave up on trying to get this to work with pulseaudio and I am currently working on using bluez 4 to connect directly to alsa. For a number of other reasons, I abandoned using raspbian an...
by jbuehl
Sun Aug 21, 2016 9:04 pm
Forum: Troubleshooting
Topic: Pi as A2DP sink - SBC decoding error; audio completely stops
Replies: 3
Views: 2037

Re: Pi as A2DP sink - SBC decoding error; audio completely s

I'm seeing the same behavior on my Pi 3 running Raspbian 8.0, bluez 5.23, and pulseaudio 5.0. I think the root cause is wifi interference with bluetooth. I have the wlan0 interface disabled because if it isn't, the audio is choppy, but occasionally it just goes silent for a while and I see the "SBC ...
by jbuehl
Mon Feb 03, 2014 7:29 pm
Forum: Advanced users
Topic: I replaced the USB connector on my PI.
Replies: 38
Views: 19197

Re: I replaced the USB connector on my PI.

What you are basically doing is building a powered usb hub. I have done that and it works just fine.
by jbuehl
Fri Jan 24, 2014 12:39 am
Forum: Troubleshooting
Topic: WLAN too slow
Replies: 27
Views: 14907

Re: WLAN too slow

No, I didn't troubleshoot it further and I just use the Asus.
by jbuehl
Fri Jan 17, 2014 3:12 pm
Forum: Advanced users
Topic: I replaced the USB connector on my PI.
Replies: 38
Views: 19197

Re: I replaced the USB connector on my PI.

Yes, the middle two pins of the USB connector are a bit closer together. I wasn't able to find a header that fit either. What I did was to take a model A RPi with the single USB connector and rotate it up 90 degrees by unsoldering the two tabs on the sides of the shield, but leaving the four USB pin...
by jbuehl
Sat Dec 21, 2013 6:12 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost (solved)

You could try newark.com.
by jbuehl
Sun Jun 02, 2013 4:27 pm
Forum: Troubleshooting
Topic: WLAN too slow
Replies: 27
Views: 14907

Re: WLAN too slow

I am currently seeing this problem when using the brand X wifi dongle that Adafruit sells for $12. I get about 500Kb/sec throughput when copying a file connected to a 802.11g access point a few feet away. This occurs on both the latest Raspbian and Arch distros. The version of the 8192cu driver is v...
by jbuehl
Wed Mar 06, 2013 3:56 pm
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

Looking at the code for read_i2c_block_data() it turns out there is a 3rd argument for specifying the length of data to read. If it is not specified, the default is 32. Setting it to 4 causes only 4 bytes to be returned. This still doesn't fix the problem of the status being set to 1. I would be int...
by jbuehl
Wed Mar 06, 2013 12:07 am
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

I can see a burst of data on the SDA line that lasts about 34 milliseconds. It looks like the clock period is 10 microseconds, so that would indicate that there are approximately 34 bytes being transferred (340 clock cycles) and that's consistent with 2 bytes being sent from the master and the slave...
by jbuehl
Tue Mar 05, 2013 9:16 pm
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

I tried a range of different values from 0 to 31. There are always 32 bytes read, even when I initialize the data array to a length of 4. The values are almost the same, but not quite, and the results are not repeatable, i.e. if I run the program again, the results aren't identical. I'm now wonderin...
by jbuehl
Tue Mar 05, 2013 8:46 pm
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

Thanks techpaul. I am not familiar with the I2C monitor. Is that a hardware device? It occurs to me that I might be using a different version of the python smbus binding or the i2c-dev driver. I'm using Arch linux and I don't remember where I got the i2c-tools package from. That could account for th...
by jbuehl
Tue Mar 05, 2013 8:22 pm
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

Actually it doesn't work that way. Setting the array size to 4 doesn't prevent it reading a lot of bytes. I originally initialized it to [0,0,0,0] and it was much larger after I did the read. Anyway, that doesn't explain the status of 1.
by jbuehl
Tue Mar 05, 2013 6:51 pm
Forum: Python
Topic: Adding a second but different I2C device to the BMP085
Replies: 30
Views: 11057

Re: Adding a second but different I2C device to the BMP085

This thread was very useful. I have this sort of working, however when I use read_i2c_block_data(), the status that is returned has a value of 1, even if I increase the delay after the write. The device is also sending a lot more than 4 bytes of data. Looking at this document http://www.phanderson.c...
by jbuehl
Wed Jul 04, 2012 4:18 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost

Looking at Raspberry-Pi-Schematics-R1.0.pdf sheet 3, LAN9512 pins 14 (PRTCTRL2) ana 16 (PRTCTRL3) are attached to the anodes of D11 and D10 respectively. and are sensing the state of the power pins on the ports. They are NOT supplies to the 9512. On a different circuit they can be used to control a...
by jbuehl
Thu Jun 28, 2012 12:11 am
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost

Here's mine. I used 30ga wire. I doubt that bigger wire would be a problem.
IMG_0812.JPG
IMG_0812.JPG (55.39 KiB) Viewed 6535 times
by jbuehl
Wed Jun 27, 2012 7:04 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost

I don't think the pi-pass creates the hot swapping problem for a high current device like the USB-N10 because it just didn't work in the first place, at least for me. In my case, I couldn't get it to function until I did the pi-pass. I'm pretty sure it would reboot the RPi if you plugged it into an ...
by jbuehl
Wed Jun 27, 2012 1:15 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost

I'm running a USB-N10 in the top port and a Logitech C250 webcam in the bottom port with the pi-pass. Maybe I'll try swapping them and see if it makes a difference. It doesn't make sense that the ports would behave differently unless there was solder bridging an adjacent pin or something. Update: Ye...
by jbuehl
Tue Jun 26, 2012 2:20 pm
Forum: General discussion
Topic: USB Port Current Boost (solved)
Replies: 247
Views: 89983

Re: USB Port Current Boost

The 9512 datasheet http://www.alldatasheet.com/datasheet-p ... N9512.html shows the diodes going the same way as the RPi schematic http://www.raspberrypi.org/wp-content/u ... s-R1.0.pdf, i.e. the arrows point away from the device.
by jbuehl
Mon Jun 25, 2012 8:33 pm
Forum: General discussion
Topic: Raspberry Pi are already evolving
Replies: 20
Views: 4474

Re: Raspberry Pi are already evolving

I think you are confusing me with someone else who did the HDMI swap. All I have done so far is to remove some unused connectors and add the jumper to increase USB power. I do intend to replace the USB connector and possibly the SD card connector. I won't try changing chips, though. Too many teeny l...
by jbuehl
Mon Jun 25, 2012 2:11 pm
Forum: General discussion
Topic: Raspberry Pi are already evolving
Replies: 20
Views: 4474

Re: Raspberry Pi are already evolving

I almost reported that post to the NSPCRP* :shock: That's pi abuse if I ever saw it. ______ * To international members - we have a charity in the UK called NSPCC National Society for the Prevention of Cruelty to Children - I leave you to work out the rest. ;) Actually, these projects remind me of t...
by jbuehl
Mon Jun 25, 2012 6:06 am
Forum: General discussion
Topic: Raspberry Pi are already evolving
Replies: 20
Views: 4474

Re: Raspberry Pi are already evolving

I'm not done yet ;) Stay tuned ...
by jbuehl
Sun Jun 24, 2012 10:14 pm
Forum: General discussion
Topic: Pi compatible WIfi adaptor
Replies: 27
Views: 37241

Re: Pi compatible WIfi adaptor

It depends on the encoding of the video, but h.264 encoded 1080p video should be around 6Mb/sec. I just did a quick test where I copied a 20MB file from the RPi and it transferred at about 10Mb/sec so I think there's no inherent bottleneck in the hardware.

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