Hi, which small small and portable monitors would you suggest to combine with Raspberry Pi.
As Raspberry Pi is part of huge range of different project please suggest which would be best in each of these categories.
If there are multiple choices in each category please rate it also by quality and price: best quality and best bang-for-a-buck
I think you have to decide what matters most to you in the monitor.
Do you want:
The answers to these questions will help you to determine where and how to search for your monitor.
Some options:
Portable DVD players/Second DVD player screens/Portable TVs
Some portable DVD players, car rear view mirror camera screens, and portable TV screens have composite inputs. They are made by a large variety of manufacturers. They often have built in speakers and sound inputs. They may or may not come with car/AC adapters. They may have included batteries. The resolution is usually much lower than comparable computer monitors. Verify that the screen has composite input, and then verify if the connectors are on the device, or if the composite A/V input requires some sort of "AV-in" conversion cable. Re-purposing these screens for your Raspberry Pi may save you some money and still fit your needs.
Professional photography/videography screens
Some monitors have been created for use in digital photography and videography, such as those made by Lilliput. They usually have an internal/external battery and often have HDMI input, and have the option of sun shades to deflect sunlight, as well as mounts (usually for being mounted to a camera or tripod. The resolution and brightness may be the best you can find. However, the price is quite a bit higher than some of the other monitors available in this size.
Car PC / Carputer monitors
There are also a fair number of "carputer" screens, some of which have DVI/HDMI input and even touchscreen functionality. The cost for these screens is higher, and the touchscreen may or may not be easy to set up in Linux, and they may only accept DC power natively (due to being designed for use in cars) but it may provide you with a more complete solution when all is said and done.
Standalone monitors (USB)
The next set of monitors to look into would be the standalone USB monitors, such as those made by MIMO and Lilliput. Upon first glance, they seem like the best option, because they only require USB input, but display drivers may be hard to come by, and the Raspberry Pi may not be powerful enough to feed the screen the power it needs.
Small computer monitors/touchscreens
Some small computer monitors or touchscreens also exist on the market, mainly by Mimo and Lilliput again. Some of these monitors have touchscreen functionality. These are differentiated from professional photographer screens by their lack of battery power. Driver support for touchscreens may work, or may not. Tread carefully. These monitors tend to be on the more expensive side, in general.
Conclusion
If price didn't matter to me, I probably would have purchased one of the Lilliput monitors, but price does matter to me, so I didn't.
I ended up deciding on a DVD "second screen" that had an included mount and AC adapter on eBay.
Sound inputs are included, and it has AC power. I don't plan on my usage requiring anything too fancy in the resolution department, and I was looking for the most cost-effective way to get my Raspberry Pi running. Getting it from ebay meant that I paid a pittance ($20), but I had to lurk around a lot of different auctions to find it at that price, since they're usually closer to $50. This also means that I don't have a warranty and I'm purchasing a product more or less sight unseen, so I may not have the image quality that I was originally hoping for. In my case, it worked fine when I hooked it up, as evidenced below:
It all depends on what you value most in your screen. Your mileage may vary.
I know this isn't exactly what you're looking for, but you might find this interesting.
You can purchase a lapdock, made for a cell phone, that will provide you a portable keyboard and monitor for use with your RPI. Simply connect an HDMI to HDMI micro female adapter to the lapdock.
They are often on sale for ~$60. Likely far cheaper than any other monitor you will find. and it's designed to be portable.
Here's a website that gives you a full rundown on how to accomplish this. http://rpidock.blogspot.com/2012/05/raspberry-pi-and-motorola-lapdock.html
Here is where you can purchase the cable needed for hdmi specifically. http://www.ebay.com/itm/280761232832?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_2827wt_1163
If you there going for THE cheapest display, I think this would be it.
There are some china-special monitors for sale on places like eBay and amazon in the $55-65 range. I picked one of them up, and they have a HDMI, VGA and A/V input. I've already tested the raspberry pi on all three and was able to get it working at multiple resolutions. The stuff above the native resolution will interlace and becomes hard to read on the small screen, and the native resolution is a weird, 6:9 WVGA standard of 800x480p60, but raspbian supported it just fine through HDMI, through my HDMI->VGA converter and even on the composite video output. It's nice and crisp at that native resolution, and looks reasonably good at anything close to or less than that. The higher resolutions look ok, if you can tolerate the interlace, but my primary interest was to have something I could plug multiple pi's into, and getting a huge resolution was not a priority. I had a little trouble getting a sunxi OS to push the native resolution. (Xorg keeps resetting it even if I force it with xrandr or fbset, and Xorg doesn't auto-detect well with the framebuffer mode) As a result, I could only seem to get either the 1920x1280 or 1280x720 modes to work consistently with a sunxi booted system on the HDMI/VGA connectors and could only get NTSC or PAL standard resolutions to work on the A/V. (both of these are fuzzier than forcing the A/V to 800x480) So currently I have one RPi connected to the HDMI, another to the VGA with the adapter, and a BPi connected to the composite. You can switch between the three with the remote. (and I have a iogear multi-link keyboard/touchpad - nice little set-up with my primary pc and laptop on the main monitor HDMI/VGA respective!)
