# Cheap EFIS finally coming.

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##### Moderator
We've had a lot of discussion on HBA about affordable instruments. Something like the Dynon Skyview IMHO, but at a tenth of the price. This might finally be the "missing link":

Delft University of Technology: Cookie wet

Open source hardware and software and a whole number of integrated sensors. Once we have affordable sensors outputting to a normal standard (USB, or whatever), we could hang an iPad on it and spend the rest of the money on other nice things.

#### PTAirco

##### Well-Known Member
autoreply;184262w Once we have affordable sensors outputting to a normal standard (USB said:
Or better yet, an android....

#### Battson

##### Well-Known Member
At first glance I thought this must have been an old thread, from back in the days before cheap avionics were being mass-produced
Given the time and effort involved to make them, the prices you can have EFIS / EMS for these days are fantastic IMHO.

I made my own wiring harness for the COM/intercom/anunciator system - thought I'd save myself 200 bucks. Not doing that again. For the quality of the products you get, you can never outdo the guys with all the right experience and all the right tools, for cheaper. Especially not if you value your time at anything more than minimum wage. I can only image an EFIS would be 100x harder for Joe-average.

That'd be my 2c.

#### Jay Kempf

##### Well-Known Member
Or better yet, an android....
EXACTLY! Build it for Android and all the geeks in the world are working for you. Build it for Apple and Steve Jobs will come back from the dead and try to profit from it.

#### Jay Kempf

##### Well-Known Member
At first glance I thought this must have been an old thread, from back in the days before cheap avionics were being mass-produced
Given the time and effort involved to make them, the prices you can have EFIS / EMS for these days are fantastic IMHO.

I made my own wiring harness for the COM/intercom/anunciator system - thought I'd save myself 200 bucks. Not doing that again. For the quality of the products you get, you can never outdo the guys with all the right experience and all the right tools, for cheaper. Especially not if you value your time at anything more than minimum wage. I can only image an EFIS would be 100x harder for Joe-average.

That'd be my 2c.
It takes a lot of pin crimping tools and specific knowledge to paste electronic components together. Been there in the lab with the maginfying glass trying to figure out how to connect this USB thingie to this Bluetooth thingie to this GPS thingie, to this Autopilot thingie. And in the micro UAV world it is all TINY! The good news is it all can be done and is being done. Open source inertial navigation already exists.

#### Kristoffon

##### Well-Known Member
I have a Samsung S3 android phone with maybe 5 apps installed which freezes and locks up randomly all the time. Sometimes when I plug in the charger the touchscreen register movements in a mirrored fashion. I'd refuse to fly in any aircraft with an android or ipad flight instrument panel. Maybe as a navigation aid, gps map, but never as anything I couldn't go without during a landing for more than a split second.

Usb is a very complicated network and prone to failure, and one single misbehaving device can bring the whole usb network down and even the host device (the efis or computer). Hackers use special usb sticks they plug into computers to bypass login screens. It is an extremely bad idea to use it in an aircraft. Cars use CAN which is many times better for that particular purpose, it is cheap, and the basis of many proprietary systems used in certified aircraft, but of course you don't have consumer devices for that.

The "integrated sensors" that come on that thing might even be identical to the ones you get on an efis, but the difference is the ones you get on the efis went through a calibration lab that measured their values on a test bench and, using a microscope and a laser perhaps driven by an actual person and not a machine, cut some tiny bits of their silicon so that their reading is much more precise. A 1% difference in absolute pressure reading equals about 300 feet. You'd be lucky to get an off-the-shelf pressure sensor with 1% error. Then you might think "oh I'll just check the airport's air pressure reading and calibrate from that" but then don't forget to calibrate over a range of different temperatures and pressures as well or you could only land on a single airport when the temperature is at a single particular value.

Open source hardware is generally more expensive, not cheaper.

Comparing an ipad to a dynon efis on the basis of price is like figuring out piston engines are much cheaper than jets then wondering why don't airlines use piston engines anymore.

##### Moderator
Usb is a very complicated network and prone to failure, and one single misbehaving device can bring the whole usb network down and even the host device (the efis or computer). Hackers use special usb sticks they plug into computers to bypass login screens. It is an extremely bad idea to use it in an aircraft. Cars use CAN which is many times better for that particular purpose, it is cheap, and the basis of many proprietary systems used in certified aircraft, but of course you don't have consumer devices for that.
Ah, didn't know that, thanks.
The "integrated sensors" that come on that thing might even be identical to the ones you get on an efis, but the difference is the ones you get on the efis went through a calibration lab that measured their values on a test bench and, using a microscope and a laser perhaps driven by an actual person and not a machine, cut some tiny bits of their silicon so that their reading is much more precise. A 1% difference in absolute pressure reading equals about 300 feet. You'd be lucky to get an off-the-shelf pressure sensor with 1% error. Then you might think "oh I'll just check the airport's air pressure reading and calibrate from that" but then don't forget to calibrate over a range of different temperatures and pressures as well or you could only land on a single airport when the temperature is at a single particular value.
Wouln't that be different for drones? I would think they need about the same accuracy as us don't they?

#### Doggzilla

##### Well-Known Member
HBA Supporter
I have a Samsung S3 android phone with maybe 5 apps installed which freezes and locks up randomly all the time. Sometimes when I plug in the charger the touchscreen register movements in a mirrored fashion. I'd refuse to fly in any aircraft with an android or ipad flight instrument panel. Maybe as a navigation aid, gps map, but never as anything I couldn't go without during a landing for more than a split second.

Usb is a very complicated network and prone to failure, and one single misbehaving device can bring the whole usb network down and even the host device (the efis or computer). Hackers use special usb sticks they plug into computers to bypass login screens. It is an extremely bad idea to use it in an aircraft. Cars use CAN which is many times better for that particular purpose, it is cheap, and the basis of many proprietary systems used in certified aircraft, but of course you don't have consumer devices for that.

The "integrated sensors" that come on that thing might even be identical to the ones you get on an efis, but the difference is the ones you get on the efis went through a calibration lab that measured their values on a test bench and, using a microscope and a laser perhaps driven by an actual person and not a machine, cut some tiny bits of their silicon so that their reading is much more precise. A 1% difference in absolute pressure reading equals about 300 feet. You'd be lucky to get an off-the-shelf pressure sensor with 1% error. Then you might think "oh I'll just check the airport's air pressure reading and calibrate from that" but then don't forget to calibrate over a range of different temperatures and pressures as well or you could only land on a single airport when the temperature is at a single particular value.

Open source hardware is generally more expensive, not cheaper.

Comparing an ipad to a dynon efis on the basis of price is like figuring out piston engines are much cheaper than jets then wondering why don't airlines use piston engines anymore.
If anybody wants to know how this works in a vehicle... look at the jeep cherokee. It has a main bus wire, and any component failure on the bus will kill input from all of them.

Freightliner has an omni-wiring that will alert you even if a light bulb goes out. It requires an extra wire on every component, but it allows incredibly detailed tracking of all electrical parts.

But when it comes to accuracy, off the shelf instruments can be very accurate. Digital components are typically very accurate, because they are already manufactured at the uM level. We can produce LEDs with billions and billions of pixels... and not one be off...

The issue is not the product, but the programming... poor programming ergonomics, leads to accurate readings being misconstrued.

#### cheapracer

##### Well-Known Member
Log Member
Or better yet, an android....
Android flying your plane? that is so 1980's ....

#### Jay Kempf

##### Well-Known Member
I have a Samsung S3 android phone with maybe 5 apps installed which freezes and locks up randomly all the time. Sometimes when I plug in the charger the touchscreen register movements in a mirrored fashion. I'd refuse to fly in any aircraft with an android or ipad flight instrument panel. Maybe as a navigation aid, gps map, but never as anything I couldn't go without during a landing for more than a split second.

Usb is a very complicated network and prone to failure, and one single misbehaving device can bring the whole usb network down and even the host device (the efis or computer). Hackers use special usb sticks they plug into computers to bypass login screens. It is an extremely bad idea to use it in an aircraft. Cars use CAN which is many times better for that particular purpose, it is cheap, and the basis of many proprietary systems used in certified aircraft, but of course you don't have consumer devices for that.

The "integrated sensors" that come on that thing might even be identical to the ones you get on an efis, but the difference is the ones you get on the efis went through a calibration lab that measured their values on a test bench and, using a microscope and a laser perhaps driven by an actual person and not a machine, cut some tiny bits of their silicon so that their reading is much more precise. A 1% difference in absolute pressure reading equals about 300 feet. You'd be lucky to get an off-the-shelf pressure sensor with 1% error. Then you might think "oh I'll just check the airport's air pressure reading and calibrate from that" but then don't forget to calibrate over a range of different temperatures and pressures as well or you could only land on a single airport when the temperature is at a single particular value.

Open source hardware is generally more expensive, not cheaper.

Comparing an ipad to a dynon efis on the basis of price is like figuring out piston engines are much cheaper than jets then wondering why don't airlines use piston engines anymore.
I have a Motorola Android. Works flawlessly. It's probably smarter than me.

I am not sure about your comments on USB. USB seems to be a lot more reliable than the original serial hardware it replaces. And with technology and aviation one thing I know is that the certified world is always holding on to things long after they are obsolete. What makes you think that a system connected with USB cables has to have ports available to hackers? Hackers have better things to do like sending me spam over the internet.

#### Doggzilla

##### Well-Known Member
HBA Supporter
I have a Motorola Android. Works flawlessly. It's probably smarter than me.

I am not sure about your comments on USB. USB seems to be a lot more reliable than the original serial hardware it replaces. And with technology and aviation one thing I know is that the certified world is always holding on to things long after they are obsolete. What makes you think that a system connected with USB cables has to have ports available to hackers? Hackers have better things to do like sending me spam over the internet.
Or coming near expensive thing in ways which make people prone to kicking their asses...

But seriously, Elon Musk uses USB in the Tesla cars, he once talked about how he had an issue finding cords and it held up his production line. He ended up sending out all his employees to buy all the cords they could find in person....

I have not known USB to crash because of one component... Im not sure how accurate he is being, but I sure as hell know that serial is awful for autos. I think USB is a bit different, since it uses time sharing, and so a bad input by one component means nothing during the time used by another component.

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
. Im not sure how accurate he is being, but I sure as hell know that serial is awful for autos.
It's not the serial part that causes the problems. It's the poor implementation. USB is serial, as is CAN. CAN is very reliable and has built in error detection/resolution. Undetected errors are on the order of 10^-13. Add a dual channel and it is as robust as any of us will likely ever need.

AGATE's CANaero has a resolution for altitude of 1 foot over a range of -5000 to 131,072. Most other resolutions are X/10^16 so the software is not a limitation. CANaero is open-source and has already, at least partially, been implemented on Arduino hardware. It's not too much of an extrapolation to expect to be able to plug an Ipad or Android device into a CAN network as one (or more) of the node(s). Someone may have already done that using an Arduino blue tooth module?

I've worked with CAN in an industrial setting for a couple of years and the only problems we had were with hardware that couldn't take the vibration. A decade and a half later I'd expect the hardware to have improved? After that I helped setup a CAN system on a prototype firetruck on a Freightliner chassis using CAN. It was a huge improvement in flexibility, installation time and overall cost compared to the existing method of custom wiring harnesses for each vehicle. CAN is good stuff - if done correctly.

##### Moderator
As I see it, the only "missing link" is sensors that translate data (TAS, gyro, pressure, GPS) into a signal consumer hardware can use. So essentially a "black box" with sensors that interfaces with Adroid/iPad/whatever.
Software for iPad's etc exists and can be expanded. If the price of such a "black box" can be brought down to a few hundred dollars/euro's, reliability is no longer an issue IMHO. Simply install 2, or 3 and take the backup one if the first one goes berserk.

I think the much bigger market for drones can make such a complete "black box" possible for GA aircraft too.

#### Jay Kempf

##### Well-Known Member
As I see it, the only "missing link" is sensors that translate data (TAS, gyro, pressure, GPS) into a signal consumer hardware can use. So essentially a "black box" with sensors that interfaces with Adroid/iPad/whatever.
Software for iPad's etc exists and can be expanded. If the price of such a "black box" can be brought down to a few hundred dollars/euro's, reliability is no longer an issue IMHO. Simply install 2, or 3 and take the backup one if the first one goes berserk.

I think the much bigger market for drones can make such a complete "black box" possible for GA aircraft too.
I would think a few hundred dollars could be a retail price for such a black box. The sensors can be more or less robust and cost would be dependent on that.

What I see is a compass, simple airspeed indicator, altimeter in the cockpit and those just simple digital output screens you can put in a very small patch of available cockpit real estate. The rest virtual. And that means NO panel at all. That would be somewhat revolutionary. The square feet of panel would all be on fold out or flip up stalks or mounts. They could also be powered stowable like the TV screens on an airliner or the NAV screen on modern stereos. Two small tablet touch screens one just in front of the side stick and one just in front of the throttle quadrant. The other screen just above your knees that folds down for panoramic views and can be put up somewhat in the way for large format moving map/HUD style functions. I have modeled a glider style cockpit with this setup and it is just a completely unhindered cockpit in terms of being able to move your body but having all the functionality and more of a normal panel. It feels very natural to sit in a mockup with this setup. Think of how a well arranged car cockpit is setup. In this country your right hand on the shifter with lots of functions arranged right at your fingertips. Most important fault conditions just flash in front of your eyes to tell you to look at other information. Not distracting at all. Most dash systems are heading to touch screen for a lot of fancy functionality. It is getting more commonplace and more reliable every year. The idea of a software only system means you can make all the changes you want and you can integrate any cross functionality you want.

#### Doggzilla

##### Well-Known Member
HBA Supporter
It's not the serial part that causes the problems. It's the poor implementation. USB is serial, as is CAN. CAN is very reliable and has built in error detection/resolution. Undetected errors are on the order of 10^-13. Add a dual channel and it is as robust as any of us will likely ever need.

AGATE's CANaero has a resolution for altitude of 1 foot over a range of -5000 to 131,072. Most other resolutions are X/10^16 so the software is not a limitation. CANaero is open-source and has already, at least partially, been implemented on Arduino hardware. It's not too much of an extrapolation to expect to be able to plug an Ipad or Android device into a CAN network as one (or more) of the node(s). Someone may have already done that using an Arduino blue tooth module?

I've worked with CAN in an industrial setting for a couple of years and the only problems we had were with hardware that couldn't take the vibration. A decade and a half later I'd expect the hardware to have improved? After that I helped setup a CAN system on a prototype firetruck on a Freightliner chassis using CAN. It was a huge improvement in flexibility, installation time and overall cost compared to the existing method of custom wiring harnesses for each vehicle. CAN is good stuff - if done correctly.

#### haiqu

##### Well-Known Member
If you can get it to put out an analog signal, it can be digitized with very very inexpensive parts. Almost the entire world relies on digitizers, I think they use some calculus called a fourier transform, if you are interested in reading up on how they actually digitize the signal within the chips...
Fourier transform is used for complex analog signals, like Software Defined Radio. I think you'd only need a simple Analog to Digital converter for this application.

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