I'm aware that this is not comparable to a 800x480 display but if you just want to output some simple monochrome graphics the 1.6" Nokia 3310/5110 Displays are quite nice. Very easy to drive and really dirt cheap - they can be found for about $3!
Add a dirt-cheap screen to the Raspberry Pi B+
41–50 of 66 posts
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#42This is an awesome post. A number of older laptop screens use this "standard" and you can just take off the screen and repurpose it. The trick is that sometimes the flex cable between the screen and the laptop has extra stuff on it. Time to go panel hunting for some more panels :-)
I was wondering recently what the interface is on my old Nokia N800 tablet, for just this reason, but I'm reluctant to take it apart to find out. And I still have a soft spot for my trusty old N800. I also have an XO-1 OPLC laptop, but it has a funky display. Hmm. I have an old IBM T60 in my junk pile, maybe that could be used...
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#43Earlier quoted context omitted.
This comes up every time someone mentions the corruption. We don't power off our many pis, but they are on UPSs (we use them for a security system.) However, the corruption happens so much that we keep disk images and have a spare on hand when we have to reboot them for any reason because 1/4 of the time they will not boot up. Even if it were corrupting the FILES being written when hard booted, it shouldn't corrupt t…
> Even if it were corrupting the FILES being written when hard booted, it shouldn't corrupt the FILESYSTEM being written. That's not how SD cards work unfortunately. When an SD card erases data, like if it's updating a file allocation table, it has to erase an entire block of flash and not just the bytes you care about. The card will throw the block into a cache in memory, erase the block, and then rewrite the parts…
I wish we had a filesystem that was tuned to the peculiarities of flash memory. It should be aware of the large erase blocks and optimize for that.
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#44Earlier quoted context omitted.
How does this compare with some the Raspberry Pi screen kits from China? I see you can get a generic Pi LCD for $7.65, a 5" LCD with video in for $18.75, and a touchscreen Pi size kit for $19.90[1]. Going to the effort of breaking out DPI through the GPIO was quite creative. If optimized do you think these can hit sub $5? Either way, this was very clever. Thank you for taking the time to document this for others! [1]…
So, these are almost all crappy clones of this: http://www.adafruit.com/products/1601 It's fine for static images and low quality video, but its using the SPI bus and a custom driver. This severely limits size of the display and/or refresh rate.
Yeah. This might change if the Chinese companies get wind of this technique; if I recall correctly these kinds of parallel LCD panels aren't all that expensive. (Edit: Actually, the controller chip used in those existing Pi LCD modules seems to support the required interface, it's just not pinned out. They could probably make new versions of the modules that are wired up properly.)
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#45Earlier quoted context omitted.
And then you have to buy a graphing calculator anyway because no high school teacher / university professor will let you take tests with it.
Because of cheating? How can you use the Raspberry Pi (in a calculator shell) to cheat, in such a way that you can't use a ti-89 to cheat? Most cheating will be by either storing crib notes on the device (which won't do you any good in math if you don't understand the concepts), or by running a program to solve a problem for you, both of which the ti-89 is more than capable of doing -- that is its whole purpose, is t…
Wifi?
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#46Earlier quoted context omitted.
And then you have to buy a graphing calculator anyway because no high school teacher / university professor will let you take tests with it.
Because of cheating? How can you use the Raspberry Pi (in a calculator shell) to cheat, in such a way that you can't use a ti-89 to cheat? Most cheating will be by either storing crib notes on the device (which won't do you any good in math if you don't understand the concepts), or by running a program to solve a problem for you, both of which the ti-89 is more than capable of doing -- that is its whole purpose, is t…
During my high school exams, every calculator would get reset by a teacher/supervisor beforehand. Harder to do with such a device.
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#47This really should be the next thing the RPi team tackles, IMO. It's nice we have this great cheap computer, but trying to find a screen to plug into it is terrible. A computer monitor or TV is fine, but both of them draw too much power and are far too big and stationary. And have you seen the prices of small HDMI screens? I can buy a 8" Windows tablet, full PC mind you, for the price of a single 5" HDMI screen. Far…
If you want a screen, just buy a $50 tablet. The Raspberry Pi is basically a tablet computer chip minus the tablet.
I see your point, but that's far less fun! :)
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#48This really should be the next thing the RPi team tackles, IMO. It's nice we have this great cheap computer, but trying to find a screen to plug into it is terrible. A computer monitor or TV is fine, but both of them draw too much power and are far too big and stationary. And have you seen the prices of small HDMI screens? I can buy a 8" Windows tablet, full PC mind you, for the price of a single 5" HDMI screen. Far…
I'm also still waiting for this one: http://techcrunch.com/2014/10/21/pi-pads/ It looks like the official site is down atm but they mention an introduction in 2014 in their FAQ. It's a 640x480(!), 7" touchscreen.
You can pick up a 7" touchscreen (1280x800) that works with a DPI display like this blog post mentioned right here: https://www.adafruit.com/products/2354
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#49Earlier quoted context omitted.
And then you have to buy a graphing calculator anyway because no high school teacher / university professor will let you take tests with it.
Because of cheating? How can you use the Raspberry Pi (in a calculator shell) to cheat, in such a way that you can't use a ti-89 to cheat? Most cheating will be by either storing crib notes on the device (which won't do you any good in math if you don't understand the concepts), or by running a program to solve a problem for you, both of which the ti-89 is more than capable of doing -- that is its whole purpose, is t…
Standardized test calculator rules in this country are not governed by reason.
For instance, a TI-89 is allowed on the SATs, but a TI-92 is not. Basically the same calculator, except the TI-92 has a qwerty keyboard. How would a tiny little qwerty keyboard actually give you an advantage on a test like the SAT? Who the hell knows. Remember 10 or so years ago when teenagers were all typing on telephone keypads?
On the other hand, the advantage of a TI-89 (with a CAS) over a TI-83+ (without one) is fairly extreme.
(Also, anyone who bothers to google it can trivially get around the reset key combos for at least 83+ line: http://brandonw.net/calculators/fake/ Somebody who takes the time to program their calculator for cheating on a test can do this)
Re: Add a dirt-cheap screen to the Raspberry Pi B+
#50Earlier quoted context omitted.
And then you have to buy a graphing calculator anyway because no high school teacher / university professor will let you take tests with it.
Because of cheating? How can you use the Raspberry Pi (in a calculator shell) to cheat, in such a way that you can't use a ti-89 to cheat? Most cheating will be by either storing crib notes on the device (which won't do you any good in math if you don't understand the concepts), or by running a program to solve a problem for you, both of which the ti-89 is more than capable of doing -- that is its whole purpose, is t…
There are two camps on why teachers might disallow calculator:
1) fear of cheating
2) because the teachers want you to do the calculation
When I took my Calc and my engineering courses, my teachers would not allow calculators. They would make sure the numbers are nice, not some crazy number or pi to calculate with. Volts, current, all those numbers are so nice we can do on the paper. I like that because it means the teacher actually put effort to ensure the numbers are not just random, they mean something to the teacher who created the exam (even though they might just change the number next semester).