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by JohnCollis
Sat Aug 05, 2017 8:57 pm
Forum: Networking and servers
Topic: Two Raspberries one ethernet cable
Replies: 5
Views: 1315

Re: Two Raspberries one ethernet cable

After changing internet service provider several times I have wireless routers to spare! I have used an old Orange router with wireless disabled, for my Raspberry systems, others provide wired connection for other appliances. If you require more ports simply connect another router via one of the Eth...
by JohnCollis
Tue Mar 07, 2017 11:29 am
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

Finally managed to find time along with reasonable weather conditions that didn't clash with shifts at work! Image of half moon taken yesterday evening with Pi Camera module (lens removed and attached via adaptor) to Skywatcher 130 reflecting telescope, default settings for camera module, origninal ...
by JohnCollis
Wed Nov 30, 2016 10:35 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Use RPi as memory for processor?
Replies: 16
Views: 3014

Re: Use RPi as memory for processor?

Older 16 bit processors didn't have enough pins for separate data and address buses, they were multiplexed onto the same pins with an address/not data select pin. The following may work, I haven't looked at any hardware or software limitations: i/p to raspberry: 16 GPIO ports for address/data; 1 GPI...
by JohnCollis
Tue Oct 11, 2016 10:40 am
Forum: Bare metal, Assembly language
Topic: SD card access
Replies: 2
Views: 1033

SD card access

Is it possible to access the SD card from a bare metal environment without a file system in situ?
by JohnCollis
Tue Oct 11, 2016 10:38 am
Forum: Bare metal, Assembly language
Topic: Vector table
Replies: 7
Views: 2451

Re: Vector table

Many thanks for your replies. I have original Pi B, a B+ and a zero, I've adopted the "create the vector/interrupt jump table at 0x8000 and then block copy to 0x0000" approach.
by JohnCollis
Mon Oct 10, 2016 3:01 pm
Forum: Bare metal, Assembly language
Topic: Vector table
Replies: 7
Views: 2451

Vector table

I am trying to use software interrupts, but for this I obviously need to initialise the exception vector table. I am basing everything on Baking Pi, which initialises to 0x8000 as the entry point and has no exception handling. If I define a section in the linker file that starts at 0x0004 (first ent...
by JohnCollis
Wed Mar 16, 2016 9:17 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

I am using the camera for imaging rather than guiding. I'm interested in obtaining images of anything, Jupiter and the Moon at the moment. I'm also interested in experimenting with trying to image stellar objects and experimenting with Registax.
by JohnCollis
Wed Mar 16, 2016 9:08 pm
Forum: Camera board
Topic: Help/advice please
Replies: 3
Views: 858

Re: Help/advice please

Could the problem be due to insufficient power to the system? I have experimented with a USB hub and with a single output to the micro USB I get evidence of horizontal lines on the images. With the USB hub connected to provide power through the micro USB plus a connection to one of the USB ports the...
by JohnCollis
Mon Mar 14, 2016 9:27 pm
Forum: Camera board
Topic: Help/advice please
Replies: 3
Views: 858

Help/advice please

I have obtained an image that consisted of multiple horizontal lines of various colours and no discernible image (the file is too large after trying the camera with my telescope. The target was the crescent moon. I am using the camera on an HDMI adapter/extender system and has worked previously with...
by JohnCollis
Mon Mar 14, 2016 4:58 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

I have a Skymaster 130mm reflecting telescope with a Pi camera (lens removed) in place of the normal eye piece.
What would be the optimal settings for the camera?
by JohnCollis
Thu Feb 18, 2016 2:00 pm
Forum: Camera board
Topic: Camera Module far from Raspberry
Replies: 8
Views: 1500

Re: Camera Module far from Raspberry

There is an adaptor available that enables the use of an HDMI cable between the camera and the Raspberry. https://www.raspberrypi.org/blog/camera-board-extension/ http://petitstudio.blogspot.co.uk/2015/04/the-raspberry-pi-camera-extension-cable.html I have successfully used this with an HDMI cable t...
by JohnCollis
Tue Feb 09, 2016 5:12 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

I have acquired the necessary parts for an adaptor for the raspberry camera. I have removed the lens from the camera and attached it to the adaptor. This afternoon I tried it with the telescope pointing at the sun via a solar filter of course. Using the raspberry camera app on my iPad all I obtained...
by JohnCollis
Mon Feb 08, 2016 1:20 pm
Forum: Troubleshooting
Topic: Latest NOOB images
Replies: 3
Views: 579

Re: Latest NOOB images

Thanks. I hadn't realised because in the past I've always had a network connection and it is only because I'm trying it out on a zero that I've noticed this.
by JohnCollis
Mon Feb 08, 2016 1:14 pm
Forum: Troubleshooting
Topic: Latest NOOB images
Replies: 3
Views: 579

Latest NOOB images

I have downloaded 1.6.0 zip file and the os folder only contains Raspbian. On boot raspbian is the only option available
by JohnCollis
Fri Jan 22, 2016 2:09 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

Many thanks, it makes sense now.
by JohnCollis
Fri Jan 22, 2016 1:45 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

I got the wrong end of the stick and made things far too complicated for myself! I've identified a suitable webcam adapter on Amazon http://www.amazon.co.uk/Webcam-adapter-in-1-25-fitting/dp/B019QOGRLQ/ref=sr_1_1?ie=UTF8&qid=1453469486&sr=8-1&keywords=Webcam+Adapter+1.25 If I understand correctly, I...
by JohnCollis
Fri Jan 22, 2016 12:04 pm
Forum: Camera board
Topic: RaspberryPi Camera for Astrophotography
Replies: 345
Views: 105645

Re: RaspberryPi Camera for Astrophotography

How would I connect the Pi camera to the T-adapter? The PT-LH020RPM is relatively cheap except the package costs far outweigh the price of the device itself.
by JohnCollis
Wed Aug 05, 2015 2:20 pm
Forum: Networking and servers
Topic: Ad-hoc wireless connection
Replies: 2
Views: 579

Ad-hoc wireless connection

This has probably been asked before, but I would like to connect my Raspberry to my iPad via a wireless link without going through my home network, with the wi-fi being available from startup on the Raspberry.
by JohnCollis
Mon Jun 22, 2015 7:16 pm
Forum: Camera board
Topic: camera module mmal error - help!!
Replies: 71
Views: 76766

Re: camera module mmal error - help!!

I started to get this error suddenly this afternoon after the camera had been working earlier. The same message was on two different machines. I think the cable was dislodged from the camera module, after I replaced it the message appeared, this was while the module was powered.

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