I have been using this monitor but really it is only a backup for me (in case the networking fails). Typically what I do is use my laptop (macbook pro) over VNC, which works nicely. I prefer the laptop, but the small monitor does work in a pinch.

Note: (a) I need to clamp down the monitor stand to my field table, which is not ideal, and (b) I needed to build a little cable to go from my anderson powerpole power connection to the 12V input for the monitor.

My emergency kit also includes a standard little usb mouse & keyboard with usb hub. I got this foldable keyboard with touchpad , hoping that I could use with with bluetooth, but it did not work, and now reading the fine print I see it does not say "Linux" as a supposed OS. Not sure why, and looking forward to other suggestions on this thread for a little foldable keyboard/touchpad combo.

I looked into doing this since I would rather have a very inexpensive field setup that I don’t care if it gets damaged by dew etc, but then found that there are some incredibly cheap laptops out there with decent battery life. I found a deal where there was a refurbished Acer swift 1, with something like 10 - 17 hrs battery life for about $190. I added a 500 gb sata m.2 drive for $60. So in the end I got a laptop with usbc and usb3, an all night battery, a decent screen, good hard drive space, and a step up from a raspberry in performance for $250. I found that the price was less than one I could put together with a raspberry and the components. Also it should be more dew resistant.

It will talk to my raspberry pi’s in the observing field just as well as an expensive laptop and will probably work better than one with a raspberry pi.

I also considered the pinebook pro, but it is not coming out for awhile yet.

I wiped off windows and installed kubuntu. Performance is looking great so far. I am planning to use a red screen gamma program to turn the screen red. The screen is already not that bright, and with a color correction program, it looks good enough to not need a red acrylic screen

Probably at home I will still use my MacBook Pro inside to talk to my pi in the driveway, but on an observing trip in the field I think this cheap little laptop would be a great solution. I will still use the pi mounted to the scope, but this will be a good way to manage the session etc.

Astro :
Maybe the simplest way for observing on the field is to use kstarslite on your cellphone, connected to your Pi using the WIFI. I don't use it right now as most of my astro time is dedicated to astrophoto but as far as I remember, it worked well enough.
In the indi setup on klite, you have a paddle to centre your object. You also have an all-red night vision theme. this should meet your expectations. You should probably add an RTC (Real Time Clock) to you Pi. it only costs 4/5 bucks . Just sync the clock home, before starting.

-Marc

I've been using the banggood hd portable monitor for a while and it's good for the price. It will even accept non standard resolutions if you desire. I power it with battery packs and a USB to 12v adapter.
For interface I have an lg wireless keyboard.
Sometimes dew can form on the trackpad, and for that I have a small USB powered heating pad.

I have tried several solutions to the pi in the field problem. I have a dedicated "Field Pi" all set up with the right connections and I can the connect via VNC from my laptop, just like I do on my home setup. It all works well, when it works well. However when there is a problem on the Pi and I cannot connect , the only way to diagnose is by connecting a screen/keyboard and mouse to the Pi. This is in effect a full PC set up. So I think the problem is mis stated. It should not be, how do I connect a screen to a field Pi, but rather what kit do I need in the field.
One solution is the PC/pi free route eg smart mount, DSLR local storage, it works its simple and its light, but you loose all sorts of useful features,
If you want INDI/EKOs in the field, then you need a processor, a keyboard/mouse and some sort of screen to see what is going on. Indi/Ekos is very resource light and therefore the obvious solution is not a Pi but a cheap laptop running Ubuntu. I have loaded The Ubuntu version of INDI/EKOs and its easy, there are excellent instructions here: Ubuntu Instructions .

Before this revelation I would take my Pi and travel gear on vacation to a dark sky and spend half my time trying to fix problems. Now laptop based its much more straight forward.

No, if something goes wrong with my pi, I connect my laptop directly to it with an Ethernet cable and fix whatever it is over vnc. I never bring a monitor or keyboard. Typically issues that it has have to do with WiFi, such as wanting to host a network or choosing what network to join. The laptop can be used to solve this problem.

Now that being said, a good idea would be to bring a backup pi or sd card just in case, but I haven’t done that yet .

Here's my mobile setup.
Everything is powered by 4 separate batteries.
Elecrow 10.1 Inch Raspberry Pi 1920X1080p Resolution HDMI.
Wireless keyboard/mouse (logitech/amazon) - actually want to switch to wired (no batteries).
The setup lasts for 5-6 hours...

Thank you for all the recommendations.

In the past I have used my laptop (Linux) on the field. But I was under the impression that I could get a better energy efficiency/cost ratio with a pi+screen.
Also I do not want to take my latest laptop to the field. My previous laptops (that I keep around) have relatively bad energy efficiency and performance and their batteries probably won't last 1/2 hour.

Well, clearly 30 minutes won't cut it, but for me, using a laptop with my pi isn't a power issue since the laptop is closed for most of the session after things are set up and running on the pi. In fact, to just quickly check up on things mid session, I often vnc in with the vnc app on a phone or tablet.

In your shoes, I would choose the Logitech K400, I've used it many time, and with many different devices. Grab a protection plan for a few bucks in case of damage and you're good to go!