Go to advanced search

by stefanv
Wed Jun 13, 2018 2:56 pm
Forum: Troubleshooting
Topic: RPi3 Bluetooth and Wifi don't play well together
Replies: 52
Views: 13421

Re: RPi3 Bluetooth and Wifi don't play well together

Perhaps the new Pi 3B+ fixes this issue. Does anyone know?
by stefanv
Wed Jun 06, 2018 1:37 am
Forum: Other projects
Topic: Raspberry pi 3 b+ Tablet
Replies: 7
Views: 436

Re: Raspberry pi 3 b+ Tablet

Yes, it's a PowerBoost 1000C. The only time I've ever had undervolt warnings was when plugged in and using an inadequate power supply (when plugged in, the external supply powers the Pi directly, so if it's inadequate, the voltage will be too low). The CPU will get quite hot if I over do it, e.g. ma...
by stefanv
Wed Jun 06, 2018 12:23 am
Forum: Other projects
Topic: Raspberry pi 3 b+ Tablet
Replies: 7
Views: 436

Re: Raspberry pi 3 b+ Tablet

I've built a tablet using a Pi 3, not a B+, and get about 10 hours of battery life out of it. It's about the size of a typical 7" Android tablet and about twice as thick (17.6mm). Together with a portable Bluetooth keyboard and mouse, I now use this, instead of a laptop, when traveling (for e-mail, ...
by stefanv
Tue May 08, 2018 7:47 pm
Forum: Graphics programming
Topic: Making a Webpage from a glade-made app in RPii
Replies: 1
Views: 432

Re: Making a Webpage from a glade-made app in RPii

You might be more likely to get responses if you post your question in the General Programming Discussion sub-forum, since your question has nothing to do with Graphics Programming.
by stefanv
Thu Mar 01, 2018 2:58 am
Forum: Troubleshooting
Topic: RPi3 Bluetooth and Wifi don't play well together
Replies: 52
Views: 13421

Re: RPi3 Bluetooth and Wifi don't play well together

I eventually gave up trying to get two Bluetooth devices and the WiFi working simultaneously with my Pi tablet's built-in Bluetooth, and hardwired in a compact USB Bluetooth adapter. They are literally the size of a fingernail when removed from their case, and take up almost no room. bluetooth2a_sm....
by stefanv
Thu Oct 05, 2017 5:52 pm
Forum: General discussion
Topic: Using Pi as Desktop, how to manage RAM?
Replies: 14
Views: 3881

Re: Using Pi as Desktop, how to manage RAM?

I use my Pi as a laptop replacement ( A Compact Home-Made Raspberry Pi Tablet ), and have tweaked a few things to get the most out of it. Overclocked the SD card, a Lexar 300x 32GB UHS-1 class 10 card, using dtparam=sd_overclock=100 in /boot/config.txt Set gpu_mem=32 in /boot/config.txt. I'm using c...
by stefanv
Fri Jun 30, 2017 1:12 pm
Forum: Other projects
Topic: E-Reader Questions
Replies: 1
Views: 596

Re: E-Reader Questions

I can't help with the software, as I haven't tried any packages for this yet, but having just built a Pi tablet , I do have some thoughts on your other questions: 2. Any recommendations on 'tablitifying' the desktop? What Desktop Environment would best suit something like this? The end goal being 'I...
by stefanv
Wed Jun 28, 2017 2:14 pm
Forum: Other projects
Topic: Yet Another Raspberry Pi Tablet
Replies: 6
Views: 1957

Yet Another Raspberry Pi Tablet

I've just finished the construction of my Raspberry Pi 3 based tablet. Mine certainly isn’t the first Pi-based tablet, as Googling “Raspberry Pi Tablet” will show, but I think that at 195x112x17.6mm (just a hair bigger than the touchscreen itself) and 484g, it's the smallest and lightest that anyone...
by stefanv
Wed Jun 21, 2017 4:06 pm
Forum: Official Foundation Display
Topic: Need to see more content on your 7in Touch display?
Replies: 11
Views: 5932

Re: Need to see more content on your 7in Touch display?

The touch knows nothing about a changed Screen Resolution. It's still useable with a pen, but not very accurate in case of small touch Icons. Nevertheless, OS Buttons are still useable. It's more a case of whether X deals properly with the mismatch between the touch resolution and screen resolution...
by stefanv
Tue Jun 20, 2017 4:03 pm
Forum: Troubleshooting
Topic: RPi3 Bluetooth and Wifi don't play well together
Replies: 52
Views: 13421

Re: RPi3 Bluetooth and Wifi don't play well together

I'm seeing exactly the same problem with a K380 keywboard and T630 mouse. Either one alone works fine, but if both are active, both work unreliably (such as forever repeating keys, etc.). It would be great to fix this without resorting to either a Bluetooth or WiFi dongle, since one of the nice thin...
by stefanv
Tue Jun 13, 2017 7:04 pm
Forum: Official Foundation Display
Topic: V1.0 has brightness control
Replies: 14
Views: 3953

Re: V1.0 has brightness control

Another possibility, I think, would be to build just the low pass filter (R32, R33, and C74 from ali1234's schematic) on its own little board (one could even use a piece of strip board and through-hole components), connect it to U1's pin 3 and ground on the V1.0 controller board, and drive it from t...
by stefanv
Tue Jun 13, 2017 3:02 pm
Forum: Official Foundation Display
Topic: V1.0 has brightness control
Replies: 14
Views: 3953

Re: V1.0 has brightness control

By the way, I don't think the chip is drawing parasitic power through -SHDN, at least not when the display is lit. It's probably drawing power from the ATTINY's P0 pin (and hence the display only lights up when P0 is high). If it were drawing parasitic power through -SHDN, the display would stay lit...
by stefanv
Tue Jun 13, 2017 2:51 pm
Forum: Official Foundation Display
Topic: V1.0 has brightness control
Replies: 14
Views: 3953

Re: V1.0 has brightness control

I know this is an old thread, but followed the link here from a new thread. :-)

Would it be possible to unsolder pins 4 and 5 of U1, lift up that side of U1 (perhaps while heating pins 1, 2, and 3), and then connect pins 4 and 5 to their correct pads using fine wire?
by stefanv
Fri Jun 09, 2017 1:58 am
Forum: Troubleshooting
Topic: Bad interaction between i2c-rtc overlay and Chromium
Replies: 0
Views: 289

Bad interaction between i2c-rtc overlay and Chromium

I'm posting this in case it saves anyone else some grief. I recently put together a RPi 3 system running Jessie, and added one of those $2 DS1307-based RTC modules from eBay. I found various instructions on-line on how to configure it, generally involving enabling I2C, loading some modules in /etc/m...
by stefanv
Thu Jun 08, 2017 5:23 pm
Forum: C/C++
Topic: Writing clean code isn't hard!
Replies: 138
Views: 8715

Re: Writing clean code isn't hard!

I think it boils down to: Writing clean code isn't hard; cleaning dirty code is. :-)

BTW, the project I've been working on during the course of my career was originally written in B, then ported to C shortly before I came along (but still looked very B-like), and has recently been made C++ compliant.
by stefanv
Thu Jun 08, 2017 5:06 pm
Forum: C/C++
Topic: Writing clean code isn't hard!
Replies: 138
Views: 8715

Re: Writing clean code isn't hard!

Adding a totally pointless prototype just before the actual function stops the warning message! I think that the compiler is correct in complaining. What if you were to call this function from another file? Then you would need the prototype (in a header file #Included by both). The real issue here ...
by stefanv
Thu Jun 08, 2017 4:40 pm
Forum: Official Foundation Display
Topic: Controller Board v1.2
Replies: 7
Views: 1512

Re: Controller Board v1.2

Note that the 1.1 board also supports dimming the backlight.
by stefanv
Thu Jun 08, 2017 4:38 pm
Forum: Official Foundation Display
Topic: Need to see more content on your 7in Touch display?
Replies: 11
Views: 5932

Re: Need to see more content on your 7in Touch display?

That "screen" capture isn't really representative, because it shows what's in the frame buffer (1024x614 pixels), not what is actually displayed (1024x614 pixels squished into 800x480 pixels). I.e., it's not really a screen capture, but a frame buffer capture. However, I could see this technique bei...
by stefanv
Thu Jun 08, 2017 4:21 pm
Forum: Other projects
Topic: DIY Power supply units
Replies: 3
Views: 927

Re: DIY Power supply units

If you have enough Pi 3s connected to the power supply, it will meet the minimum load requirements, so you won't need to do anything special. As for how many you can run from one PSU, you need to look at the current limit of the PSU's 5V output, and divide that by the per-Pi current. In my experienc...
by stefanv
Sat Jun 03, 2017 12:54 am
Forum: Raspbian
Topic: Raspbian Logo Just for Fun
Replies: 0
Views: 349

Raspbian Logo Just for Fun

I was just taking a break from my RPi-based project, playing around in Photoshop, combining Tux the Linux penguin (image from https://pixabay.com/en/tux-penguin-animal-cute-linux-158547), and the Raspbian raspberry (as rendered at https://wall.alphacoders.com/big.php?i=293739). Here's what I came up...
by stefanv
Fri May 26, 2017 3:45 pm
Forum: Wolfram Language
Topic: i dont see any point
Replies: 18
Views: 12947

Re: i dont see any point

scruss wrote:Waterloo alum much, Stefan? :D
You could say that. ;-)

I've been working with Maple (and on Maple) since before Mathematica existed.

My point of course is that anyone who was a big Maple fan would also see the point of Mathematica, since it's roughly the same as the point of Maple.
by stefanv
Fri May 12, 2017 5:16 pm
Forum: C/C++
Topic: Writing clean code isn't hard!
Replies: 138
Views: 8715

Re: Writing clean code isn't hard!

Adding a totally pointless prototype just before the actual function stops the warning message! From gcc manual: -Wmissing-prototypes (C and Objective-C only) Warn if a global function is defined without a previous prototype declaration. This warning is issued even if the definition itself provides...
by stefanv
Fri Apr 21, 2017 1:15 am
Forum: Raspbian
Topic: Temporarily disabling USB ports bumps lxpanel to 100% CPU
Replies: 0
Views: 488

Temporarily disabling USB ports bumps lxpanel to 100% CPU

I'm not sure if I should have put this in the Raspbian sub-forum, or one of the hardware ones ... I'm working on an RPi3 application where I need to be able to disable the USB and Ethernet ports (to save about 200mA), which I'm doing using, sudo echo 0x0 > /sys/devices/platform/soc/3f980000.usb/busp...
by stefanv
Fri Mar 10, 2017 5:00 pm
Forum: Wolfram Language
Topic: i dont see any point
Replies: 18
Views: 12947

Re: i dont see any point

stderr wrote:
curlyc wrote:i just dont see why this is a valid thing to learn
Big Maple fan?
If he were a big Maple fan, he would see the point. Mathematica wouldn't be his choice of product to use, but he would know its purpose.

Stefan (big Maple fan)

Go to advanced search