Bendix KN62A, KR 87 and KX155

Questions about deployment and use of Air Manager Instruments

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jasong
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Bendix KN62A, KR 87 and KX155

#1 Post by jasong » Tue Dec 03, 2019 12:41 am

Hello,

I'm starting a new project for the following Bendix KN62A, KR 87 and KX155 radio stacks. I hope I can create these as Arduino hardware and AM panel instrument or at least share what I've done to help others with the same projects in mind. Similar to what I did with the KT76A viewtopic.php?f=14&t=2432&sid=460257ac9 ... e4b9d2001d.

So this is where my first problem is - trying to find small led digit display.

On the real units (original Bendix units converted to Frasca Sim Instruments) I have, they use vacuum gas (I think/ :? ) digit displays, these require what looks like +24 v and +190v to work - which I won't be using. I also don't have wiring diagrams.
So I plan to use Arduino and AM.

Starting first with the KX155 which is the bigest display, it requires 20 digits.
kx155.jpg
The length of 10 digits is about 65mm which bendix achieve by using a 1 bit instead of 7 bits saving space on the display.
Currently i have found .28" digits on ebay and using a 2 digit plus 3 dight = about 37.5mm- Can I cut a digit or does it break the circuits?
https://www.ebay.com/itm/0-28-0-36-0-4- ... 0008.m2219

Do LCD displays work with AM
https://www.ebay.com/itm/AU-0-91-IIC-I2 ... 2914582636
https://www.ebay.com/itm/AU-0-96-I2C-II ... 2911858217

Any toughts on using these types of LED displays?
https://www.ebay.com.au/itm/Display-LED ... SwW4dbyJO- (I have found these cheaper on a USA electronics site for about $1+- each, just ebay links are easier to see the units)

Common Cathode or Anode with regads to the controller boards? I don't understand which to use?

I'm open to any ideas or suggestions Thanks for any help.
KR87
kr87.jpg
KN62A
kn62a.jpg

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Sling
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Re: Bendix KN62A, KR 87 and KX155

#2 Post by Sling » Tue Dec 03, 2019 8:54 am

Jason,see responses inline below.

Can I cut a digit or does it break the circuits?
Absolutely not. You can get some modules that do have the left hand digit as a one only so it may pay to keep looking.

Do LCD displays work with AM?
Yes, but only those with a HD44780 driver work natively. Other tyes such the I2C ones you linked could be interfaced using message port but this requires a descent level of scripting ability in both AM and Arduino.

Any toughts on using these types of LED displays?
Any 7 segment display in its raw form can be interfaced. There are some caveats. Read my response to the common cathode/anode question. These are a bit pricey and common anode so not the best pick.

Common Cathode or Anode with regads to the controller boards? I don't understand which to use?
Think of an anode as positive and a cathode as negative. When a module says its common cathode it means all the individual segments have their cathodes(negatives) tied together. This means you can turn all the segments on or off together by applying or removing a common low to this single pin. The individual segments can be controlled by applying the appropriate high to the individual anodes(positives). It's obviously the opposite for common anode. The MAX7219 only supports common cathode as it tends to be more common.

I hope this helps.

Tony

jasong
Posts: 96
Joined: Sun Oct 20, 2019 8:18 am

Re: Bendix KN62A, KR 87 and KX155

#3 Post by jasong » Wed Dec 04, 2019 5:45 am

Thank you Tony

jasong
Posts: 96
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Re: Bendix KN62A, KR 87 and KX155

#4 Post by jasong » Sun Dec 08, 2019 1:51 am

Last edited by jasong on Sun Dec 08, 2019 10:13 am, edited 2 times in total.

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Sling
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Re: Bendix KN62A, KR 87 and KX155

#5 Post by Sling » Sun Dec 08, 2019 6:00 am

Jason, all those links appear to be down from my end.

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Keith Baxter
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Re: Bendix KN62A, KR 87 and KX155

#6 Post by Keith Baxter » Sun Dec 08, 2019 6:52 am

Sling wrote:
Sun Dec 08, 2019 6:00 am
Jason, all those links appear to be down from my end.
+1

Not sure if this works by you Tony.


https://m.aliexpress.com/item/329512773 ... 5788610934

Keith
AMD RYZEN 9 5950X CPU, Corsair H80I cooler, ASUS TUF GAMING B550-PLUS AMD Ryzen Mother Board,  32Gb ram Corsair Vengeance 3000Mh, MSI GTX960 4G graphics card 

jasong
Posts: 96
Joined: Sun Oct 20, 2019 8:18 am

Re: Bendix KN62A, KR 87 and KX155

#7 Post by jasong » Sun Dec 08, 2019 10:32 am

Sorry gents, I’ve re edited the above post. If it doesn’t work it must be the links it the Ali app, So I’ll find the google links, let me Know.

In regards to the Max 7219 display tubes https://www.ebay.com.au/itm/2pcs-MAX721 ... 7e3624d908

Do you wire these up as a daisy chain? Or do you wire up each tube with their own Arduino inputs?

For the KX155 would I need 3 tube boards to cover the 20 sights required?

1 for the kr87 & 1 for the kn62?

I haven’t purchased these yet as I’m still researching how to use them.

Thanks.

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Keith Baxter
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Re: Bendix KN62A, KR 87 and KX155

#8 Post by Keith Baxter » Sun Dec 08, 2019 10:57 am

@jasong
Links now working.

Keith
AMD RYZEN 9 5950X CPU, Corsair H80I cooler, ASUS TUF GAMING B550-PLUS AMD Ryzen Mother Board,  32Gb ram Corsair Vengeance 3000Mh, MSI GTX960 4G graphics card 

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Sling
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Re: Bendix KN62A, KR 87 and KX155

#9 Post by Sling » Sun Dec 08, 2019 11:49 am

Yes the links are OK now.

The MAX 7219 modules can be daisy chained. You can connect upto 8 in a single chain but you can have multiple chains. Each chain uses just 3 I/O pins. Can i suggest you use 4 modules for the KX155 because it will make the code a lot easier for you. You can address just a single module at a time rather than having to concatenate parts of frequencies across modules. You just remove all the displays that come with them and wire back in 5 common cathode digits of your choice.

Tony

JackZ
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Re: Bendix KN62A, KR 87 and KX155

#10 Post by JackZ » Sun Dec 08, 2019 12:00 pm

If you go for MAX7219 modules, I suggest you to search for ones with LEDs displays mounted on a socket (The black support below the LEDs displays) and not directly soldered on the circuit, like this one:
59EBB364-562F-4FB4-BCCB-ED9145AD3B4D.jpeg
Like this if you want to separate each block of 4 digits for your mounting purposes, you’ll just have to use some connecting wire from the socket to the displays. The circuit module can then be put aside where needed.

Jacques
My YouTube Chanel on the A320 (Real SOPs by an Airline Pilot IRL):
https://www.youtube.com/playlist?list=P ... 0Q6SBASRqJ

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