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by jwhitmore
Wed Oct 03, 2018 7:39 pm
Forum: HATs and other add-ons
Topic: Multiple HATs and ID EEPROM?
Replies: 3
Views: 1386

Re: Multiple HATs and ID EEPROM?

Thank you for the confirmation :( I've just changed my HAT to have jumpers on it so you can disable the EEPROM, when the lines are already in use. I might look at the code which probes for attached HAT, but it probably needs a properly designed protocol between the master and the slave eeprom device...
by jwhitmore
Wed Oct 03, 2018 12:41 pm
Forum: HATs and other add-ons
Topic: Multiple HATs and ID EEPROM?
Replies: 3
Views: 1386

Multiple HATs and ID EEPROM?

I's designing a RaspberryPi "HAT" to fit onto a device which already has the RaspberryPi 7" touchscreen display. That display pretty much leaves the GPIO expansion header free for use apart from the I2C pins used for HAT Identification [1]. Now whilst I2C is can cope with multiple slave devices conn...
by jwhitmore
Wed Oct 03, 2018 12:32 pm
Forum: HATs and other add-ons
Topic: Back Powering the Pi via the GPIO Header?
Replies: 4
Views: 1896

Re: Back Powering the Pi via the GPIO Header?

Thank you for that clarification. Busy designing ;)
by jwhitmore
Sun Sep 30, 2018 11:28 am
Forum: HATs and other add-ons
Topic: Back Powering the Pi via the GPIO Header?
Replies: 4
Views: 1896

Back Powering the Pi via the GPIO Header?

Looking at designing a HAT which will supply 5V power to the RPi. As a result I'm looking at the notes on back powering [1] and specifically the link to the back powering diagram. That diagram just show that I need a protection diode in the HAT design, but isn't too specific about the type of diode ...
by jwhitmore
Sun Jun 07, 2015 10:34 pm
Forum: Troubleshooting
Topic: RPi-2 Serial issues
Replies: 9
Views: 2172

Re: RPi-2 Serial issues

GOT IT! Sorry about all this. And thanks for all the info. Turns out that the USB-Serial cable that I'm using doesn't work when it's connected behind a USB Hub. I've never encountered a device that works differently behind a USB Hub but this is it. When it's behind a powered hub the RX Path works bu...
by jwhitmore
Sun Jun 07, 2015 10:27 am
Forum: Troubleshooting
Topic: RPi-2 Serial issues
Replies: 9
Views: 2172

Re: RPi-2 Serial issues

After moving to yet another distro I still have issues with /dev/ttyUSB0. I've put a scope onto the transmit pin from the USB Serial cable and for some reason when connected to the RPi-2 it doesn't transmit. Nothing at all. Just can't understand. I have noticed a difference in what dmesg is reportin...
by jwhitmore
Wed May 27, 2015 7:30 pm
Forum: Troubleshooting
Topic: RPi-2 Serial issues
Replies: 9
Views: 2172

Re: RPi-2 Serial issues

Yes but to be honest I think I'm going to move to another Distro. Or at lease get another Micro SD and maybe install Arch Linux on that. Or revert to Raspbian on which the serial ports were working. I had difficulty with Raspbian because of older versions of installed utilities I needed so I'll got ...
by jwhitmore
Tue May 26, 2015 7:02 pm
Forum: Troubleshooting
Topic: RPi-2 Serial issues
Replies: 9
Views: 2172

Re: RPi-2 Serial issues

Yes I've done that but I think Ubuntu Mate has done something that has messed up the serial ports. both USB and the GPIO one.
by jwhitmore
Mon May 25, 2015 5:06 pm
Forum: Troubleshooting
Topic: RPi-2 Serial issues
Replies: 9
Views: 2172

RPi-2 Serial issues

There seem to be a few people farther on then me on the RPi-2 Serial. For some reason my RPi-2 is all over the place communicating with other serial devices. I've tried to use /dev/ttyAMA0 but for some reason a good 9600 channel is coming into the RPi-2 as complete garbage. It's almost like it's got...
by jwhitmore
Sun May 24, 2015 12:29 pm
Forum: Linux Kernel
Topic: Is this a valid kernel? Error message!
Replies: 0
Views: 765

Is this a valid kernel? Error message!

I've built a few kernels before but all of a sudden I'm getting an error when I try to execute the mkknlimg command to actually put together the image file. I'm cross compiling on my laptop and everything compiles without error. Well I didn't notice any errors passing through and none were listed at...
by jwhitmore
Sun May 24, 2015 8:35 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: USB Serial /dev/ttyUSB0 does not transmit
Replies: 3
Views: 1360

USB Serial /dev/ttyUSB0 does not transmit

Can't understand what is happening but eventually put the scope on Rx and Tx to see what is happening. I'm trying to communicate with an embedded device which uses a 9600 serial connection. On my openSuse desktop everything is working perfectly with a minicom -b 9600 -o -D /deb/ttyUSB0 but the same ...
by jwhitmore
Sat May 23, 2015 9:20 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

Eventually got a chance to get the scope out and connected to the SPI Bus to see what was going wrong. But to my surprise everything was as I expected it to be. So I then went back to the B+ with no Device Tree and suddenly it occurred to me what a school boy error I'd made. Well maybe it wasn't tha...
by jwhitmore
Wed May 20, 2015 12:51 pm
Forum: Raspbian
Topic: Kernel source for 3.18.11
Replies: 3
Views: 1980

Re: Kernel source for 3.18.11

Cheers for that. Just out of interest how far can you upgrade the kernel without effecting libc and other installed packages.
is 3.18.13 close enough to 3.18.11 to make no difference?
by jwhitmore
Wed May 20, 2015 11:49 am
Forum: Raspbian
Topic: Kernel source for 3.18.11
Replies: 3
Views: 1980

Kernel source for 3.18.11

I've cloned the git repo for rpi-linux from https://github.com/raspberrypi/linux.git and I'm on the rpi-3.18.y branch but there are no tags on the branch at all. I'm trying to get to the specific Raspbian version of the kernel so I can make changes to some of the compiled modules. I'm currently poin...
by jwhitmore
Sun May 17, 2015 10:34 pm
Forum: Troubleshooting
Topic: Raspbian 2015-05-05 wifi-config utility
Replies: 2
Views: 1499

Re: Raspbian 2015-05-05 wifi-config utility

Thanks a million for the pointer to that thread on 15-05-05 I'm working my way through it.
by jwhitmore
Fri May 15, 2015 9:45 am
Forum: Troubleshooting
Topic: Raspbian 2015-05-05 wifi-config utility
Replies: 2
Views: 1499

Raspbian 2015-05-05 wifi-config utility

Looking at info on an old version of Raspbian [1] has a wifi application for establishing connections why is it not in 2015-05-05? I've installed the network manager and my wifi dongle is recognised and listed in "ifconfig" but it doesn't seem to scan for networks and connect? I'll install wifi-rada...
by jwhitmore
Thu May 14, 2015 10:07 am
Forum: Troubleshooting
Topic: Network management with 2 3G/4G USB Dongles
Replies: 0
Views: 410

Network management with 2 3G/4G USB Dongles

I'm running 2015-05-05 Raspbian on a RPi 2B and trying to manage 2 USB 3G/4G dongles. It's aimed at a mobile platform where the two dongles have two different ISP providers. The idea would be that if there is no coverage from one operator then simply use the other operator. It's very hard to find an...
by jwhitmore
Wed May 13, 2015 11:58 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

No joy the old RPi B+ Don't even attempt to load that overlay file so no mention of the ds3234 on powerup.

Have to sleep on this one
by jwhitmore
Wed May 13, 2015 11:40 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

I actually have gone back to basics and decided that I was trying to get two devices working in one overlay file and that I'd strip it out and get the one I'm having a problem with into an overlay file of its own. So that's the RTC ds3234. I've given it an overlay file of: /* * Device tree overlay f...
by jwhitmore
Tue May 12, 2015 10:33 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

That deprecation warning is because it don't like my overlay file. I've tried removing the rtc but that gains me nothing as the CAN Bus controller don't work. Going back to the typo file is the best as it gives me one device. Fixing the typo gives me no SPI devices at all.
by jwhitmore
Tue May 12, 2015 8:15 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

I grabbed a fresh sd card on an RPi 2 and installed Raspbian 2015-05-05, which has a 3.18.11-v7 kernel. SPI ain't working even when [ 4.374834] bcm2708_spi bcm2708_spi.0: master is unqueued, this is deprecated [ 4.392877] bcm2708_spi bcm2708_spi.0: SPI Controller at 0x3f204000 (irq 80) Have to chase...
by jwhitmore
Tue May 12, 2015 5:27 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

How embarrassing. Thanks for your very prompt reply and sorry. I'll test this out and let you know. Rest assured I'll be kicking myself.
by jwhitmore
Tue May 12, 2015 5:11 pm
Forum: Troubleshooting
Topic: STICKY:I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.
Replies: 335
Views: 517390

Re: I2C, SPI, I2S, LIRC, PPS, stopped working? Read this.

I hope that this thread is still open for business, I have some. I keep getting diverted by work but finally getting back to this problem. I designed a board which had an SPI RTC (ds3234) and a CAN Bus Controller (mcp2515) connected to the RPi SPI bus. I had this working on the old RaspberryPi by ch...
by jwhitmore
Sun Mar 22, 2015 10:16 am
Forum: Advanced users
Topic: HW Clock register invalid
Replies: 0
Views: 335

HW Clock register invalid

I've got a ds3234 RTC connected the SPI bus of the raspberrypi B2 but on power up things happen in the wrong order. dmesg is telling me that at aprox: [ 2.712030] drivers/rtc/hctosys.c: unable to open rtc device (rtc0) but then later on: [ 4.639904] ds3234 spi0.1: rtc core: registered as rtc0 I've s...
by jwhitmore
Sun Mar 15, 2015 8:46 am
Forum: Raspbian
Topic: Shutdown from X Session
Replies: 2
Views: 585

Re: Shutdown from X Session

Brilliantly simple! That worked a treat, I never realised that sudo could do that. Obviously it's a bit more complicated then I thought so thanks a million for pointing that out. It certainly fixed my problem ;-)

Thanks again

John

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