Hi, sharing a complete solution for wall panel using cheap Android tablet. I did a test drive of the solution I plan to implement in my new house (under construction).
Here are the components I used:
Ridiculously cheap 11-inch tablet. It’s quality is really poor, and it’s super slow. I wouldn’t recommend it for anything else, but all it does ultimately is just display the dashboard, so it is fine.
I already had a cable from the tablet location to my boiler room, so I reused it to deliver 10V DC power under the tablet’s frame. The power supply is in the boiler room, and to the side of tablet’s frame the USB charger bed is attached. In the new home I plan to place it under the frame in the wall.
Software:
Fully Kiosk Browser runs on the tablet. A lot of inspiration for settings taken from this blog. I also activate the dashboard with motion detection sensor, but I didn’t want my tablet to show screen saver when not in use, but rather just turn of the screen. One problem I found is that I couldn’t turn off the mac address randomization on this model, so every time it disconnect from wifi and connect again, it has different IP address as well.
I’m a fan of node-red which I prefer over HA’s automations, so, probably a bit of overkill, but here’s how I put things together:
It could be done without functions, but I find it easier and more elegant this way.
For now there’s only one sensor + tablet, but the design is fully scalable as I plan to have 4-5 tablets in the new house.
Only open item I have is that my tablet is now 100% time connected to charger. Some people claim it may cause problem with the battery. I consider adding programmable socket to only charge it within 20-70% battery, but not sure if that’s really required.
Yeah, i have 5 or 6 tablets all over my house…
A few advices:
don’t use quick charger, battery will go bad very quickly using it. If possible disable quick charging or use classic 5V charger, not more than 2A, it’s quite enough.
If only possible, enable battery-save mode (not all tablets have that option, though) which basically charges battery to 60-80% only, to prolong it’s life;
use static IP. That’s golden rule in HA. Never use DHCP if only possible. this way you avoid problems in the future.
check out your tablet: if it’s warm (at the back specifically) then create holder so that tablet will be somewhat away from the wall - around 1cm, to enable coolling. My Xiaomi tablet begins to act funny after 3-4 years when it gets hot (picture flickers), it seems that graphics chip was affected by constant heat, since it’s ok again when i cool it down.
i think that if you have Fully kiosk plus version and enable remote access then fully kiosk integration appears in HA, so you can do everything there (you don’t need mqtt then, i guess).
i would print “something” - a cover, … to hide all those ugly cables at the left…
Lastly: when my HA grew i found out that 10inch tablet is too small, so i bought a used 15 inch x360 laptop (those have touch screen), flipped it around and mounted it on a wall. So, if your house is under construction re-think if you will need a bigger screen for your main monitor. If nothing else you will do some quick changes every now and then, and it’s almost impossible to do them on the tablet, it’s just too small for anythng serious (note that you only have half of the screen when keyboard shows!).
Thanks much for the comments. Few my comments and questions:
Should I really care about the battery if I have it always connected? In the new house I’ll have UPS and/or power bank for the PV installation, and I plan to also have connection for power generator in case of major electricity failure, so I expect the system to be always powered on. And the USB charger modules without quick charge are hard to find these days.
My frame already includes some distance from the wall, but probably I could add some vent holes into it. Will include that in version 2.0.
Agree on tablet size, I have 11" but already see it could be larger. Larger are expensive, though… and I don’t want to hand a TV in every room
I wanted to use the static IP, but I couldn’t find how to disable MAC randomization option on this tablet that I bought. That cause a whole lot of problems…
Indeed fully kiosk integration would allow to replace the IP discovery part and usage of the REST API, but… see above on IP address changes.
Hiding cables - yes, good idea, probably my next version of the cover will include that, but also in the final setup the charger will be under the frame, so only one part of the cable would be outside.
As i said, used laptops with touch screen can be found pretty cheap. Look for “x360” models.
I recently bought This touch screen monitor, it’s decently cheap, yoi only need RPi or similar and you’re done. I have it connected as a second monitor on my x360 laptop, though (for video surveillance).
Regarding battery: it will “swell”, consequently back side of tablet can “pop-off”, in extreme situations bad overcharged battery can cause fire…
I”ve had my old samsung s8 at my bed for HA screen and when battery swelled back side completely popped off.
Regarding mac: i don’t think it matters, since in HA only IP matters. I never touched MAC on any of my devices. You only set static IP, mask and GW on your tablet and you’re done. This is also important if you’ll have kiosk plus integration in HA, as it’s Ip dependant. Ok, another option is to reserve IP on your router.
The changing Mac is the problem with setting the static IP on the router.
I didn’t think of setting a static IP on the device itself. Indeed, that seems the simplest possible solution, which I shoot of with a nuke using MQTT and nodeRed
