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by rew
Tue May 07, 2019 3:41 pm
Forum: Compute Module
Topic: Two LAN9514 chips on one raspberry.
Replies: 5
Views: 500

Re: Two LAN9514 chips on one raspberry.

Yes. I need the lan ports and get the "hub" part for free. I could've maybe tried another USB-lan chip, but 1) this one works on the raspberry 2) I need at least one hub anyway. (I would've gotten by with a bare usb-ethernet chip and a LAN9512, but the complexity of two different chips is not worth ...
by rew
Sun May 05, 2019 12:23 pm
Forum: General discussion
Topic: Seeking suggestions on reusing an old tablet touch screen
Replies: 7
Views: 445

Re: Seeking suggestions on reusing an old tablet touch screen

There are very many different possible screen interface specifications. The chip on the raspberry pi can do a few of them and many screens will support one or two. The chances that those will match are slim. When a phone or tablet manufacturer designs a new phone-or-tablet, they will search the poss...
by rew
Sun May 05, 2019 12:16 pm
Forum: Compute Module
Topic: Two LAN9514 chips on one raspberry.
Replies: 5
Views: 500

Two LAN9514 chips on one raspberry.

I have a project where one Compute module (CM3) gets connected to two LAN9514 chips for Ethernet connectivity. It seems that the raspberry pi uses the last 3 bytes of its serial number for the MAC on the LAN chips. That's all nice if you have one of them, but I'd say it is not allowed when there are...
by rew
Fri Dec 28, 2018 5:18 pm
Forum: Graphics, sound and multimedia
Topic: Is Openscad ported to Raspbian Stretch?
Replies: 20
Views: 5141

Re: Is Openscad ported to Raspbian Stretch?

that I had was with finding the repository file 'libqscintilla2_qt4.so.13'. This was what his compiled copy of openscad was asking for. We found the file 'libqscintilla2_qt4.so.13.1.1', but as I said, that is not what the compiled openscad was asking for. Ah! But that one is easy if you know how th...
by rew
Wed Dec 19, 2018 2:10 pm
Forum: General discussion
Topic: pi one still supported?
Replies: 17
Views: 962

Re: pi one still supported?

Yes, I buy the Micro SD cards with adapter. So I now have plenty of adapters around to put the microSD into the original pi. The goal is to have my scanner connected and I had just hooked that up when the troubles started. Maybe the printer is outputting 12V on the VUSB? Nope. 0V. And the scanner is...
by rew
Tue Dec 18, 2018 6:12 pm
Forum: General discussion
Topic: pi one still supported?
Replies: 17
Views: 962

pi one still supported?

Hi, Is the original PI still supported? I need a "linux computer with USB and ethernet" and even a PI one would be overkill. So I thought I'd use the old pi that is collecting dust somewhere for this application, but somewhere in the process it suddenly died. And I got another pi one from the pile a...
by rew
Mon Jun 18, 2018 2:53 pm
Forum: Troubleshooting
Topic: Hooking up official 7 inch display to CMIO with Compute module 3
Replies: 7
Views: 795

Re: Hooking up official 7 inch display to CMIO with Compute module 3

You've probably solved it by now (or not).... but...

You have the FPC on the display side upside-down. The blue stuff needs to go towards the PCB. The contacts are AWAY from the PCB.
by rew
Fri Jun 01, 2018 11:29 am
Forum: Compute Module
Topic: 13 seconds boot delay
Replies: 4
Views: 2404

Re: 13 seconds boot delay

I think this can be easily fixed in the firmware: https://github.com/raspberrypi/firmware/issues/1002
(My PCB is crowded enough as it is).
by rew
Fri Nov 18, 2016 4:43 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Serial port "noise".
Replies: 3
Views: 1266

Re: Serial port "noise".

Scotty101: Thanks! That's it!

I was starting to look for the "Send this string to uart" code in the kernel and compiling my own kernel, but just extracting the uncompressed kernel from the distributed kernel.img is easier.
by rew
Fri Nov 18, 2016 12:05 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Serial port "noise".
Replies: 3
Views: 1266

Serial port "noise".

I have "stuff" connected to my UART. It does funny things when it gets sent "random" data. I see "Uncompressing " at 115200baud, then "Linux..." at around 1800kbps and 0.31 seconds later "done...\r\n" (still at 1.8Mbaud). Is there a way to prevent this output? I have: dtoverlay=pi3-disable-bt in boo...
by rew
Sun Jul 10, 2016 2:10 pm
Forum: Troubleshooting
Topic: ttyAMA0 returns EOF.
Replies: 1
Views: 522

ttyAMA0 returns EOF.

I have a "smart meter" connected to my pi (zero). I want to log the data to a mysql database, but until then I want to log the raw output to a file... cat /dev/ttyAMA0 >> thelogfile.log that should do the trick. (besides setting the baud rate). I've configured my pi not to do serial console. There i...
by rew
Sat Mar 26, 2016 6:38 pm
Forum: General discussion
Topic: Interaction setting the font and changing the resolution?
Replies: 0
Views: 376

Interaction setting the font and changing the resolution?

A friend has a pi, that was used with a TV. i.e. a lot of pixels but you tend to sit a long distance away. So I increased the console fontsize. Now she bought a small display. When setting the display mode using "tvservice" , the screen always blanks, and never comes back. Could it be that changing ...
by rew
Sat Mar 26, 2016 6:33 pm
Forum: General discussion
Topic: How reliable is the Raspberry Pi 3
Replies: 19
Views: 9386

Re: How reliable is the Raspberry Pi 3

Using the compute module is IMHO only advised if you really need 'pi compatiblity and price is of no concern.
by rew
Tue Mar 01, 2016 2:10 pm
Forum: Beginners
Topic: PI 3 and Raspbian Wheezy
Replies: 48
Views: 41923

Re: PI 3 and Raspbian Wheezy

you may get away with sudo apt-get update && sudo apt-get dist-upgrade sudo rpi-update sudo reboot So far I can report that this does NOT work. I just get the rainbow square. The green led sends MORSE: - - - - . . . . (dash dash dash dash dot dot dot dot (pause) ) UPDATE: I thought I had upgraded t...
by rew
Tue Dec 15, 2015 5:57 pm
Forum: General discussion
Topic: Adding more RAM - presumably impossible?
Replies: 84
Views: 22108

Re: Adding more RAM - presumably impossible?

It's quite possible that SD cards can claim 40Mbyte per second or even more, but certain restrictions in the interface between the processor and the SD card mean that the pi cannot use the fastest communication method with modern SD cards. With a 32-bit bus and 900 M transfers per second, the DDR on...
by rew
Tue Dec 15, 2015 9:59 am
Forum: Raspbian
Topic: Calling a script when WIFI attaches.
Replies: 2
Views: 1119

Re: Calling a script when WIFI attaches.

Thanks Dougie. I thought: let's look in the source where that file (or a pointer to it) gets stored, but as far as I can tell, this command will attach to wpa-supplicant and then wait for the event to happen and execute the script whenever it happens. That would mean I'd have to put it in a startup ...
by rew
Mon Dec 14, 2015 11:35 am
Forum: Raspbian
Topic: Calling a script when WIFI attaches.
Replies: 2
Views: 1119

Calling a script when WIFI attaches.

Hi, I've mounted a "zero" on my bike. I want it to connect to my home- and work-wifi when I get there. That works. But I also want to trigger running a script to synchronize things: upload the measurements that it has taken over the trip. Everybody suggests that I use an "post-up" script. This works...
by rew
Mon Dec 14, 2015 11:27 am
Forum: Raspbian
Topic: Lite faster than Full version?
Replies: 4
Views: 2711

Re: Lite faster than Full version?

The main reason for "lite" is that it is meant as "non desktop" so there are less files to download and install. It is a good starting point for a server, the non-lite for when you want to use it as a workstation.
by rew
Tue Jul 07, 2015 10:32 am
Forum: Other projects
Topic: Open source USB DMX-512 with RDM (Enttec USB Pro protocol)
Replies: 12
Views: 7959

Re: Open source USB DMX-512 with RDM (Enttec USB Pro protoco

Hi cyrano, Thanks for the feedback. We've changed to the "new look" because google warned us that our site was "hard-to-use" on mobile devices. We now use a "standard" layout that is supposedly better. According to Google the new version is better (they seem to be rendering the site on tons of virtu...
by rew
Thu May 14, 2015 9:47 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI has more speeds
Replies: 15
Views: 46306

Re: SPI has more speeds

Just FYI: I think the datasheet has a typo. It says: "CDIV has to be a power of two", while it intended to say: "CDIV has to be a multiple of two". This suspicion is strengthened by: "Odd numbers rounded down.". There is also a hardware-explanation for this: The SPI and I2C modules in the BCM2835 (a...
by rew
Mon Jul 21, 2014 8:08 pm
Forum: Automation, sensing and robotics
Topic: MCP4728 Quad DAC Help
Replies: 11
Views: 4934

Re: MCP4728 Quad DAC Help

I2C addresses are 7 bits. The eighth bit in the "addressing byte" specifies read/write. This read/write bit is the lowest bit. Now, some people say that the address is "0xC0" and that to read you need to send "0xC1". They mention the WHOLE byte, not just the top 7 bits representing the address. It a...
by rew
Mon Jul 21, 2014 8:00 pm
Forum: Automation, sensing and robotics
Topic: 433 what?
Replies: 46
Views: 10355

Re: 433 what?

The signal from the transmitter will be 100 times more powerful if the transmitter is at 1m than when it is at 10m. And both have to work. So.... the receiver has an automatic gain control. It will amplify the signals it recieves until it recieves SOMETHING. The led is supposed to flicker all the ti...
by rew
Mon Jul 21, 2014 7:46 pm
Forum: Troubleshooting
Topic: B+ second boot issues
Replies: 10
Views: 2173

Re: B+ second boot issues

That would be a hint that your bootcode.bin is the one listed as "old" above, dated 8 jul. I.e. too old to boot a B+.....
by rew
Mon Jul 21, 2014 7:39 pm
Forum: Troubleshooting
Topic: B+ External Hard Drives
Replies: 10
Views: 15664

Re: B+ External Hard Drives

I now have a "decent" setup that can measure the output capabilties of various powersources. Interesting to measure powersupplies marketed as "2A" and then finding out that they max out at 0.35A (just like most 0.5A supplies...)! Anyway, the best powersupply so far is one advertized as 2A which mana...
by rew
Mon Jul 21, 2014 7:28 pm
Forum: Beginners
Topic: Pi photoframe
Replies: 4
Views: 1896

Re: Pi photoframe

Instead of "*.jpg" use ` find . -name \*.jpg` Now the problem is with the filenames/directories that have spaces in them. So the command becomes: find . -name \*.jpg -exec fbi {} + The problem with this is that the number (actually total size) of the arguments to a command in Linux is limited. So if...

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