I am seeking a display to use with an Arduino for an aircraft dashboard. Ideally it needs to be about 3" tall and preferably wider than it is tall but square would work. It needs to be readable in strong daylight so some display types might be better suited than others. I will have about 8 sensors driving the code, including rpm, exhaust gas temp, air pressure, fuel sensor, etc , so all simple.
I am intending to display one circular dial for Airspeed with numerical values for Altitude, etc and a sliding bar indicator for the exhaust gas temps, fuel.
Would anyone care to recommend an inexpensive display with driver and a suitable small Arduino to host it please?
As you say, the biggest problem would likely be sunlight readability. You could mitigate this somewhat by where you place the display within the cockpit.
You might find that one of the commercial Android tablets may have the type of display that meets your requirements.
As for the Arduino host, you are probably looking at one of the ARM based boards as the AVR based boards (UNO, MEGA2560 etc) don't have the RAM or speed to annotate dials.
How do you intend to acquire the data to drive the display? If you make a physical connection to the aircraft systems, are there certification issues?
I've never used one of these myself, but the waveshare clockface type of board might suit your needs. Most of the hard graphics work is done by the displays hardware, so all your arduino has to do is pass the numeric values you want displayed. [Preformatted text](https://www.waveshare.com/product/1.28inch-lcd-module.htm) Other options are some of the smaller "shield" type I2C displays, but again, you want something with enough grunt so your Arduino just concentrates on passing the numbers, not managing graphics.
I played with a round display similar to that one. Mine was just as dumb as any old rectangular LCD. I did load a watch face bitmap onto it but it needed much more grunt than my UNO could provide.
Dashboards are usually designed so that the gauges are shielded from direct sunlight either by using some type of hood or by being tunneled into the dash.
This screen has worked well for me. YMMV
Thank you to everyone for your responses.
Markd - you raise a sound point about certification, but the aircraft is a microlight, so certification is less of an issue than it might be for a larger aircraft.
I can probably manage to shield the display from sunlight, but the extensive canopy will mean that it will be in bright light on most days. Perhaps a cowl around the display will help. I was concerned that the Arduino might not have the power to drive the screen. An android screen might be an answer, but I’m fairly sure that it would be beyond my abilities to make the link unless someone had done the hard work already.
Dingo - I think the circular displays are too small. The very smallest that I could use would be 2.5” diameter. I think you are right about the display handling the processing of the graphics and I’ll follow your advice.
Hutkikz - The 3.5” (diaganol) display should do the job, though a little smaller than my preferred size. I will purchase one and give it a go. With the processing power on the board and the libraries available I’m hoping that I cannot go wrong!
Thank you all. That’s appreciated.
Tom
For 8 bit Arduino's such as Uno/Mega 3.5" is quite large and you'll need to keep things simple and localized. Complete screen redraws are best avoided.
32 bit boards such as the MKR series or esp32 can drive a 3.5" TFT pretty well if you use the tricks such as keeping animations simple and updating only the pixels that need to be updated. I have a gauge project in the works myself based on this combo.
Next up is the Teensy 4.1 the bad boy of the Arduino world. If you want a bigger screen this is the one to drive it. This is as good as it gets.
The Nextion displays are different because they have their own microcontroller that you program the graphics using their software. Since the display does all the hard work you can have a big screen using an 8 bit Uno. Here's a good thread about them.
You should not think of an Arduino as a power supply. As a microController it's good at controlling power using Transistors, Mosfets, Relays and such. Since the onboard regulator can supply only a couple hundred milliAmps in optimal conditions it's not such a good power supply.
While pretty much every tutorial shows it being powered by the Arduino it is not good practice. If I remember correctly this display uses about 150mA so it doesn't leave much for the Arduino and other peripherals.
Since the Arduino needs a power supply itself it's better to power the display from that and if you like control that power with the arduino and a transistor.
Hi Tom, sorry, I was barking up the wrong tree. There was me thinking it was for a ground based display to show info from sensors on a large RC aircraft or copter, I didnt realise you meant a proper human sized cockpit display in a real aircraft!. You probs want to look OLED displays, these are really good in strong sunlight and have great viewing angles (and "true black" for a dial background). Given your end use, the lower end Arduino UNO is seriously undergunned for driving any graphics much more than the small displays like the one I first suggested, it is about the limit for the Uno. (The small display I suggested uses a GC9A01 chipset and has its own RAM so doesn't need to redraw the whole screen each time, which reduces the workload on something low powered like an Uno. There are also some Adafruit libraries using this chipset that are much better than the Waveshare effort and will work with many other of these mini displays using the same or similar chipset. So given its a microlite you want to install it in, I would seriously look at investing in some more processing power, if you want graphics processing by the microcontroller, try an Aduino Due, a Pico or ESP32 as a processor (but watch the different voltages ) . If you are happy to explore using Raspberry Pi (and can find one nowadays without needing to win lotto), these will easily drive up to 7" touch sensitive HDMI screen, as well as handle your sensors and a keyboard etc. Another alternative is something like an Android tablet or repurposed Phone to handle 100% of the graphics side of things, communicating with the sensor info coming from an Uno (or even a BBC Micro:Bit) and design a simple readout screen in software e.g. "Processing" (for Android), MIT App inventor or similar. The 3.5" unit suggested by Hutkikz is a great suggestion, it also reduces the need to redraw screens. What ever you end up with, look for something with lots of library support, code examples, tutorials. Adafruit, Sparkfun, DFrobot are always good sources of info. Looking forward to the inflight video.
Thank you for the advice Hutkikz. I started my Arduino journey recently with a ProMicro, a BMP280 and a 1.3" display to make it simple. It has helped me to experience how sketches work and the pin-outs. I understand that my ProMicro will not be up to the job, and that is what I really meant by 'power'. Computing power. I had missed the point that the Arduino output would be insufficient to drive a screen!
My display will have a zero to 90 knot speedometer dial with a pointer and two sliding scales for exhaust and cylinder head temperatures the other info on screen will include numerical, for altitude and engine RPM plus a couple of warning 'lights' for fuel level. the screen will be black with white for the information - colour is not necessary. Let me know if I am mistaken, but if I don't redraw the screen, I'm guessing that the processing workload is quite low. I imagine that a screen with its own controller will manage much of that.
My inputs will be 2No BMP280s which will provide altitude and (by comparison between the two) airspeed, plus direct milli/microvolt input from the 2 temperature sensors and RPM pulses from the engine. The fuel level warning lights showing 10 litres and 5 litres remaining will be from light sensitive diodes.
Updates at 1or 2 second intervals for example will be adequate as the results will only change slowly.
What I shall do is purchase the 3.5" screen which has a controller and buffer ram and progress with the sketch. I shall then be in a better position to determine the most appropriate Arduino.
Thanks for your reply Dingo. I should have made it clear that it is a full sized aircraft - though small! I'm sure that Ardinos are more frequently associated with models.
It's a good point about the OLED display. In fact that was how I had considered proceeding at one time, but I was having some difficulty in finding a reasonable size at a low enough price. I was also considering an iPhone or Android display, but the software support does not seem great.
What I will do is purchase the 3.5" display and see how I get on with that. It seems well supported and I think it will be large enough. I've done a mock up of the display which will be about 4 feet away. Providing that the daylight is not an issue I believe that it will be readable. I'll attach a link to it if I can figure out how!
Try this! Dropbox - Electronic dash (1).pdf - Simplify your life
Graphics are a huge workload any way you look at it. redrawing only the parts of the screen that are changing helps reduces that to a more manageable size and aids in speeding things up.
All displays will have controllers(drivers). Only the Nextion displays have microcontrollers that are programmable and therefore reduce the workload to the Arduino but that software is another learning curve altogether.
Regarding OLED screens while they are much easier to see in sunlight they are quite small and they do not hold up well in cold temperatures which may or may not be an issue.
OK, I understand about the microcontroller on the Nexion screen now. Thanks Hutkikz. And as the temperature drops by 2 degrees Celsius per 1000 feet it can be quite cold at 10,000 feet which is the limit for a microlight here in the UK. Perhaps the OLED is not so good after all! I rarely get quite that high though. Up to about 4000' is not unusual though.
I would seriously reconsider the Android/smartphone bit - if you build 'a device' that publishes a webpage, your smartphone just becomes your display, with all the power and advantages that provides you. Not saying it's a slam-dunk, though you should be able to find lots of help and suggestions here along those lines. I just think the prepackaged phone allows you to focus on the non-display side of your project.
OK Camsysca, Thank you for your suggestion. I will look into that alongside using the 3.5" display. It might be my best solution if I can handle the code.