DIY Pi notebook
Tristan M. (2946) 1039 posts |
Not even the ATMEGA32U4 boards have turned up yet. This is going to take a long time. Recently I realised that those little screens are perfect for VR (besides resolution maybe). A quick search later reveals a lot of information on using them with a Pi to do homemade VR. I think I have everything they used lying around so when the TFT arrives I’ll have to try it out for curiosity’s sake. |
Tristan M. (2946) 1039 posts |
Some things have barely left their country of origin. I remember when post from China would have a < 5 day turnaround a few years back instead of the 1-3 months it does now. I’m sick and cranky. Let me have my grumble. |
Tristan M. (2946) 1039 posts |
I stole a few minutes to knock out an Arduino sketch for the trackpad salvaged from a dead notebook. I have it working as a USB mouse now. Most notable differences were the Y axis is inverted, and the USB and PS/2 libraries handle the scroll wheel differently. I have to look into that. Had to disable it for now because things got interesting. This gave me an idea. Probably a well trodden road, but I thought of it independently. An Arduino Leonardo or similar with the little resistive touchscreen TFT I have, functioning as a “smart” multifunction HID device. Not sure what practical use it’d be, but it’s an interesting thought nonetheless. e: Just bought a cheap “Leonardo” because using the little TFT shield as part of a USB device is intriguing. |
Tristan M. (2946) 1039 posts |
The 5" LCD arrived yesterday. It seems to be designed to fit an RPi3. The alignment of the OPiPC/2 GPIO headers in relation to the HDMI connector is a couple of mm different. So annoying! Because I didn’t have much time I had to “borrow” another family member’s Pi3 to do a quick test. Screen looks okay. Haven’t tried the touch screen. About the only gripe I have with the LCD is one that many people seem to have with it. The location of the GPIO header, or rather that it exists at all. It just uses it for optional power (also has MicroUSB for that) and SPI connections for the touchscreen. So it has a header sticking out that is rather annoying for most applications. I’ve seen that a few people cut them off somehow. |
Tristan M. (2946) 1039 posts |
Doing a quick, cobbled together test of how it would all go as a portable there were some issues. None of which were surprising. Using the Pi3 because the LCD fits on it, along with the 7" tablet keyboard case, mouse from the desktop (Haven’t finished the touchpad yet), a USB drive and the big power bank, besides packaging issues the biggest thing was the required current is just too much. The sag must have been pretty bad because the USB drive couldn’t function. I read somewhere that a Pi3 with one of those LCDs draws a peak of 3.1A. I tried again using a horribly fragile setup using the Pi Zero, 3 port hub with ethernet, same peripherals and various adaptors to tie it together. Ignoring the fragility it worked, although it was incredibly messy with the extra components. I still haven’t tried the SPI touchscreen. |
Rick Murray (539) 13851 posts |
I turned a Pi Zero and one of those little HDMI LCD panels into a portable media player using a USB hub, dual output battery, mouse (easily the largest part of the setup) and a rubber band. https://www.heyrick.co.uk/blog/index.php?diary=20180411 We might, one day, be able to manage DIY mobile RISC OS setups if and when RISC OS supports Bluetooth (so can make use of reduced size keyboards and such intended for mobiles). I don’t think I’d ever use a Pi3. It just needs too much power. Something running off batteries needs to be more power conscious. |
John Sandgrounder (1650) 574 posts |
Mine is clocked down to 400 MHz to stop it getting too hot. Making it somewhat pointless :( |
Tristan M. (2946) 1039 posts |
Hey, Rick! I read that blog entry a while back. It was part of what gave me a nudge to get the LCD. Nothing wrong with elastic bands to hold things like that together… for a few weeks maximum. I’ve made my feelings clear in the past about the RPi3 and using MicroUSB for power. A barrel connector would have been far better, although more open to people connecting the wrong voltage. John, I switched back to using my RPi3 for RO when I dismantled my Zero setup to try the LCD. Hit the orange temp zone and probably would have hit the red today had I left it plugged in. It was a warm 39*C today. The problem with my Zero is I put a right angle header connector on it. It seemed like a good idea at the time. It still is for some things. Not for this LCD though. I’ve been wanting to try another arrangement with the Zero but I’ve not had the time or cognitive clarity. Too much to do, and still affected by the mysterious fatigue and need to sleep that the recent flu like thing going around caused. Blah! |
Colin Ferris (399) 1818 posts |
Ref the FM-Radio in the Pinebook – any ideas on how to make it work ie output through the speakers? |
Steve Pampling (1551) 8172 posts |
Well if Andrew R. doesn’t have a document describing it then I think he knows how to contact a Pine engineer that does. |
David Feugey (2125) 2709 posts |
Since I listen to radio almost all day, that would be a bonus for me :) |
Tristan M. (2946) 1039 posts |
It’d be a convenient way to keep an emergency broadcast station going. It’s a shame the RPi’s FM radio can’t be used because of pad breakout issues. |
Jon Abbott (1421) 2651 posts |
Does this do what you want? |
Rick Murray (539) 13851 posts |
No, that’s a transmitter, not a receiver. And, seriously folks, do not ever do that. It’s a cool hack indeed to get a Pi to output a modulated FM signal on a GPIO pin. |
Tristan M. (2946) 1039 posts |
That’s something alright. It’s like those interesting hacks to get an esp8266 to generate a modulated video signal. I have no problem with that Pi GPIO thing being being made initially and tried to see if it would work on the bench, but it should be left at that. Even a “proper” basic FM transmitter is absolutely trivial to build. It’s barely worth it though becase they can be bought online for a few $ more nicely packaged. Yes, I was talking about receiving emergency broadcast stations. It’s getting to that time of the year here. The relevent websites always collapse like a house of cards in a stiff breeze when put under any load so radio is the way to go. I just don’t really have much around anymore with a radio receiver. |
Tristan M. (2946) 1039 posts |
I totally forgot why I came here to post! I spent some time last night fiddling with the touch screen in Raspbian. It seems to have the same chipset as Rick’s. I was unable to find the right combination for me with my initial attempt. Hopefully I can find the initial combination again because at least the tracking was smooth. Seemed like a good starting point. |
Colin Ferris (399) 1818 posts |
Rick’s got use of a ‘Spectrum analyser’ :-) Seems both the Pine & RasPi have a ‘FM radio’ built in. Getting them to work is the problem! It seems some of the ‘Android Phones’ come with ‘FM radio’ build in – but not switched on. It seems a pity – that in the UK – they want us to switch over to the old 405 TV freqs – when the rest of the world uses the standard FM freq. I wonder if you could use ‘Squeezed’ Audio on MF frequencies – so we could received good audio Direct from France/Germany – etc. As a note do any of the countries from the 1st World War – remember the fallen |
Rick Murray (539) 13851 posts |
I don’t use the touch. Already got stuff hanging off the GPIO pins…
It impressed me with being able to cope with everything I’ve thrown at it. Including the Beagle xM video. Having said that, my composite video to VGA gizmo outputs a variety of picture sizes and frame rates and some of my monitors cope with signals outside of spec. For instance the widescreen one (1344×900? something like that) suddenly came back to life when feed a 1920×1080@60Hz signal.
Likely the same reason as the Pi – it’s a radio chip that does WiFi, Bluetooth, and FM radio.
To be honest I’ve not listened to FM radio in years – I listen to Eagle 80s (Guildford area) via the internet.
Much more morbid and hard hitting here in France. They gather at the war memorial (each village has one that lists the people who died in the war). The youngest child capable of reading will read off the names and after each one everybody will say “morte pour France”. They really do not want people to forget. |
Tristan M. (2946) 1039 posts |
I meant the resistive touch aspect, however I will also say that I am quite impressed by the LCD. I have a kind of sort of opposite converter. It’s an HDMI to S-Video, composite and maybe component? I don’t really recall. S-Video is essentially compatible with the luma and chroma inputs on the old Commodore monitors. I experimented with outputting RO to a 1084DS. Looked way better than composite.
Oh. I thought the BCMxxxx had the FM radio built in, but BT and WiFi were hanging off the USB bus.
I’m not fond of the selection with the local stations. Sometimes I use Spotify. Sometimes music from my generally pretty old collection. In Australia we have ANZAC day. It’s a catch-all war memorial day, however it was started to commemorate the soldiers of WWI, more specifically those who fought and lost their lives at Gallipoli. The landing at ANZAC cove is especially ingrained in the Australian collective memory. Hmm. I wonder. Wow, Wikipedia is just as bad with Operation Totem, CSIRAC… I have to wonder what else. I think there may be an Empire PR person at work lol. |
Colin Ferris (399) 1818 posts |
I think the person in charge – was the same behind ‘Three Before Breakfast’!! It would be interesting in what the young Germans are told. |
Tristan M. (2946) 1039 posts |
Lucky there are more sources of information than the history books. It’s just a matter of who reads them. I sorted the touch ability in Raspbian. It reminds me of a finger stabby kiosk mode. Not great for a UI, but again, software. I’m using the Pi right now with the 7" tablet keyboard case in Raspbian. I need to solder some jumper wires on to the LCD for at least power, and possibly SPI before I use it with the Zero again. A Pi Zero board would fit neatly against the back of the LCD board. |
Tristan M. (2946) 1039 posts |
I feel like an inhuman monster. I clipped one end off some of my jumper wires so I could solder them to the solder pads on the LCD. Although the Zero I ordered has arrived, and I soldered a normal header on to it I ended up using the Zero with the right angle header to try to cut down on depth. Trying to use the “normal” zero on the 5" screen while plugged into the header doesn’t work out. The M/M piggyback HDMI adapter along with the HDMI to HDMI mini cable prevents access to the USB port. Using the Zero via the jumper leads does work. However I believe it’s a terrible solution. There’s the HDMI cable sticking out of the Zero, and the need to put a USB hub on. Probably the thing to do would be to use a Pi 1, plug the GPIO in and use a couple of the HDMI connectors with the little breakout boards on them and a short section of HDMI ribbon cable. This solution might also work with other things that don’t quite line up like the Orange Pi PC/PC2. The Leonardo arrived today. I haven’t tried it yet, although I did plug the LCD shield in to check for fit. No interference issues, which is nice. |
Chris Evans (457) 1614 posts |
Not sure if it would be useful, but HDMI swivel adaptors can easily be opened up and they normally use individual wires, they are also cheap! |
Tristan M. (2946) 1039 posts |
Interesting. Only way I can get those is from China. Same places I’d get the other HDMI adapters anyway. |
Chris Evans (457) 1614 posts |
“celluloid ribbon cables” are they FFC? Can you post a link please?
Under £2 on ebay in the UK and in France from EU sellers. e.g. |