MobiFlight Community Support

Dear builders,

I want to build a clock using Mobiflight and the Arduino Mega.
As I have understand, it is necessary to use the Max 7219. Unfortunately it does not show " : "
Is it possible to use for example

https://www.amazon.de/AZDelivery-Digital-Display-Arduino-Raspberry/dp/B078S8SGW2/ref=sr_1_22_sspa?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=max+7219&qid=1608982065&sr=8-22-spons&psc=1&smid=A1X7QLRQH87QA3&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzM0paMkxNUTg2SVFRJmVuY3J5cHRlZElkPUEwMDEzMzUyMlJVTFo4WllEOFlUNCZlbmNyeXB0ZWRBZElkPUEwMzg4NDQ2TFJDWlNNRjUxVElEJndpZGdldE5hbWU9c3BfYnRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Or does anybody know another possibility with 7 Segment Displays ?

Greetings

Egyptair

Hi,

this chip is not usable with MobiFlight because it uses the TM1637 chip. MF only supports I²C-LCDs and the MAX7219-chip.

Hi Stephan,

thanks. Do you know, if there are Max 7219 with ':' available ?

Greetings from EDVY

Egyptair

The MAX7219 can only drive 7 Segments with decimal point.

The MAX7219 can only drive 7 Segments with decimal point.

Not fully correct !

A Max can handle Displays with 7 Segments and a Decimal Point..... But there is no rule that the Decimal Point must be a Decimal Point all time.

Mostly Those Displays for a Clock Looks like "88:88" .... So they have no Decimal Points but have a single Pin that light the "Doublepoint"

To use it..... connect it to MAX ..... 4 Cathodes for the 4 Diggits ... 7 Seg for the Segments and the DP Pin is wired to the "Doublepoint" Pin on the Display.
In MF you enable the Decimal ( in theory no mater what decimal .... All shoud work).

Good morning,

thank you, I will give it a try, but in theory, it really should work : )

But this leeds me to the next question: Is it possible to let the Dot /doppel dot flash in Mobiflight ?
Maybe with two configs, one for the odd numbers, the other for the even numbers ? But 59 and 0 are odd, so there will be no indication for 2 seconds...

Greetings !

Egyptair

Hi

But this leeds me to the next question: Is it possible to let the Dot /doppel dot flash in Mobiflight ?

Here we got 2 Problems we need to solve.

1. Software:
Mobiflight not support a "Blinking" System at the moment. ( On the ToDoList but no timeline when or if it come )
The only way to handle this at the moment is as you expected a "logic" based on a Value.
Means the fastest Blinking is a 2 Second Sequence.... 1 Sec ON -> 1 Sec OFF -> 1 Sec ON and so on.
The "59-->00" is no problem here. We simply would use a Formula like "Seconds Modulo 2 ...$%2
Then 0%2=0 ... 1%2=1.... 2%2=0....3%2=1 ....and... 59%2=1 . So a perfect sequence of ON OFF ON at all time.

The Problem in the Software is the Decimal i think. It is possible to use a Precondition here. But it think this create some traffic. Will work but maybe can occure in trouble if config is bigger . I not try out so we need to test.
The other way is to use ONE Config for the Clock.... and another for the DoubleDot.
So the Doubledot in MF is like a additional Diggit. ( No preconditions) Config 1 Show xx xx Config 2 show the blinking : like it´s a single Diggit ( Diggit 5 on Max) .
The Config show e.g. Blank for OFF and "8" for ON.... And we just use a segement of the "8" that is wired to the Pin for the DoubleDot
BUT that bring us to Question 2.

2. Hardware:
Now we need to know... How does the Display handle the DoubleDot electrical.
It´s pretty sure a Segment Pin.... BUT What Cathode is used for it. Does it have a shared Cathode with all 4 Diggits, Does it have a own (5th) cathode or is it bind to one of the Diggits ( If Yes to what diggit).
Based on that information i can think about the wireing and if its in theory possible to use it like explane above without a Precondition System.

Hello pizman82,

thanks for the message.
I will take it step by step, first I will try to get the ':' indicated and then flashing.
If it should not work, I would go the other way and would let the '.' flash, this would be ok too, but of course, the ":" would be nicer.

I will keep you up to date, thanks again...

Greetings

Egyptair

May you missunderstand.....

The problem is not the choosing between a flashing "." Decimal or a flashing ":" doubledot.
The problem is is electrical posibility if this element is a "own" Diggit (cathode) or if it is just a segment related to a cathode of a other ( or all) other Diggits that used for the Numbers.

If own Cathode we can use it like a additional Diggit .... Here a simple formula should work perfect.
If it´s a intigrated Segment then pretty sure the only way to hanlde is the Mobiflight Decimalpoint system. and THATS a hardcoded System. Means we can not "blinking it" with a formula. Only by creating 2 Configs with Preconditions.
And here i see a little problem cause the Preconditions are NOT build to swap 60 times per minute. They are build to make a single swap by a user Input. I think they will have delays..... No problem if you use them 1 time every few minutes But maybe problematic if they used every second !

Finaly we need to test this !

I indeed misunterstood this.... this seems to be much more complicated, than first tought.

on top of this, I have seen on youtube videos, that the ':' is not flashing in the 737, it is continously displayed... I will have to find out, what the real deal it is with the ':'

Greetings

Egyptair