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by majenko
Tue Oct 08, 2019 5:31 pm
Forum: General discussion
Topic: Raspberry Pi 4 Dual Monitors
Replies: 46
Views: 11446

Re: Raspberry Pi 4 Dual Monitors

Update: two new matched 24" iiyama monitors, and still the problem persists. HDMI1 is perfect. HDMI2 is just garbage.
by majenko
Sat Oct 05, 2019 9:52 am
Forum: General discussion
Topic: Raspberry Pi 4 Dual Monitors
Replies: 46
Views: 11446

Re: Raspberry Pi 4 Dual Monitors

I am just trying to get dual monitors working on my Pi 4. Following hints above I used the edid from my primary monitor to even get to see the second monitor and its resolutions. Now I have the second monitor "working" in that the Pi sees it and configures the right resolution - and it even turns it...
by majenko
Thu Jul 14, 2016 1:47 pm
Forum: General discussion
Topic: UECIDE on Pi.
Replies: 1
Views: 472

Re: UECIDE on Pi.

Step 1: add the repository URI to apt (/etc/apt/sources.list): deb http://dist.majenko.co.uk stable main Step 2: Update repository: apt-get update Step 3: Install keyring to quell those nasty "not verified" errors: apt-get install majenko-keyring Step 4: Update again: apt-get update Step 5: Install ...
by majenko
Sun Dec 01, 2013 9:56 pm
Forum: Bare metal, Assembly language
Topic: Arduino-like libraries for bare metal programming
Replies: 6
Views: 4178

Re: Arduino-like libraries for bare metal programming

I am working on a Raspberry Pi core for my UECIDE project. UECIDE is a port of the Arduino IDE and is aimed at running with many many different microcontrollers. PIC32, AVR, Arm, etc. My latest endeavor is to make a core for compiling programs on the Pi (running UECIDE directly on the Pi) using the ...
by majenko
Fri Mar 22, 2013 4:10 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RS485 and Raspbery Pi
Replies: 9
Views: 24849

Re: RS485 and Raspbery Pi

Ok, and now to finish answering my question :) To use a MAX3485 chip and manually drive the RE#/DE lines (both lines tied to a single GPIO pin), you need to: 1. Output a 1 on the GPIO pin 2. Output your data 3. Do an fsync() or fflush() 4. Wait for TXFE to go true. 5. Wait for BUSY to go false. 6. O...
by majenko
Fri Mar 22, 2013 3:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RS485 and Raspbery Pi
Replies: 9
Views: 24849

Re: RS485 and Raspbery Pi

OK, to partially answer my own question, the Pi uses the main UART for the GPIO connector and system console. That makes sense I guess - you'd want to use the best one for the job. I have knocked together a little program to probe the UART registers, and a combination of TXFE and BUSY looks promising.
by majenko
Fri Mar 22, 2013 3:01 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RS485 and Raspbery Pi
Replies: 9
Views: 24849

Re: RS485 and Raspbery Pi

The chip I use for 3.3V RS-485 is the MAX3485 chip - half duplex, takes input from TTL level serial. It has RE# and DE lines for switching to between receive and transmit - how you drive those is up to you. I have seen schematics with MOSFETs, and with 555 timers. Ideally you would drive it from a G...
by majenko
Sat Jun 02, 2012 10:08 pm
Forum: Troubleshooting
Topic: It did work... once...
Replies: 0
Views: 682

It did work... once...

It's just one long tail of woe with me. Eventually I managed to get hold of an SD card that the Pi would work with. Fantastic, thought I. Burned Debian to it, and it worked perfectly first time. Had it running for a few hours, playing around with different things, when suddenly, out of the blue, the...
by majenko
Sat Jun 02, 2012 2:21 pm
Forum: Advanced users
Topic: iSCSI modules for 3.1.9+?
Replies: 20
Views: 9898

iSCSI modules for 3.1.9+?

Are there kernel modules for 3.1.9+ on the Pi available? Specifically: kernel/drivers/scsi/iscsi_tcp.ko kernel/drivers/scsi/libiscsi.ko kernel/drivers/scsi/libiscsi_tcp.ko kernel/drivers/scsi/scsi_transport_iscsi.ko I see the files available in various 2.6.32-5 kernels in apt, but I don't think down...
by majenko
Sat Jun 02, 2012 12:39 pm
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

dom: so you're saying that Argos and Morrison's both sell counterfeit SD cards? I never buy SD cards on eBay for exactly the reasons your link states.
by majenko
Sat Jun 02, 2012 11:06 am
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Holy moly! My "official" official card has just arrived... and it worked first time. Even though the other cards I am using are all listed in the Wiki, because I didn't buy them from Farnell they didn't work. Have these cards been modified in some way to work with the Pi so that Farnell can charge t...
by majenko
Sat Jun 02, 2012 9:37 am
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

I have now tried 2 different cards, in three different card readers, using 2 different operating systems and methods of writing. All to no avail. I am still waiting for my "official" official card from Farnell, but it's going to have to be something extra special to work. I can't believe that the bo...
by majenko
Fri Jun 01, 2012 7:24 pm
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

I will give the most recent boot code a try as suggested by Darkness - once the git repo has cloned... Nope - no different. I await my new card from Farnell in the morning (I hope) - if that doesn't work, then I am at a loss. It would be really nice to get some feedback from the Pi. What would have...
by majenko
Fri Jun 01, 2012 7:05 pm
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Right, I'm getting somewhere. I get a very brief flash of data on the SD card data lines, and the CS line flickers high briefly, at the moment of power-on. The SD card's clock line is permanently running. As this is a dedicated clock coming from GPIO48 I'm not sure if that is really correct. So ther...
by majenko
Fri Jun 01, 2012 6:15 pm
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Personally I have no complaints. We all know there is a lot that can go wrong. But I have been very impressed by the reaction from I got Farnell when it did go wrong. You're one of the lucky ones then. I am cursed with the hell that is RS's customer service. I am still waiting for a reply. You can'...
by majenko
Fri Jun 01, 2012 3:53 pm
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Should the GPIO pin that sinks the current for the OK LED be measuring 1.56V?

I'd expect that to be 3.3v (or near) for LED off, and as good as 0v for the LED on. 1.56V seems a very odd value from a digital IO pin.

It's a static DC voltage as well - not a square wave or anything.
by majenko
Fri Jun 01, 2012 11:25 am
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Ditto... ditto... ditto...

Tried 1A phone charger.

Tried 17A SMPS power supply.

Tried old class 4 SanDisk 4GB.

Been out and bought Class 10 4GB SanDisk Extreme.

All to no avail.

Supplied by RS.

Time to call them.
by majenko
Fri Jun 01, 2012 9:58 am
Forum: Troubleshooting
Topic: Red LED on Faint Green LED
Replies: 253
Views: 65046

Re: Red LED on Faint Green LED

Well, I must say, this is rather a disappointment. Yes, I have the RED on, Green pinpoint problem. Mine is from RS, and arrived (after months of waiting) this morning. It's not the power supply on mine, of that I can be certain. I started out with my 1A HTC charger adapter, and moved up to my 17A be...

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