LED&KEY module

AGCB

I've had one of these http://www.alselectro.com/7-segment-led-array---key---ic-tm1638-drive.html for a while and when I tried to use it had trouble getting anything to display. So I played with it and looked for some example SPIN code to use with it but only found a couple online that didn't work for me anyway. More playing and things started to click. So I've written a few simple programs to use the basic display options and thought I would post this to help someone else trying to get started. Also included a readme with some of what I have learned. I have nowhere near learned to use this to even part of it's potential and may post more when more is known. Hope this helps someone!
Aaron

JonnyMac

After seeing your post I thought it would be something worth having a proper library for. Most of the code I encountered was for the Arduino, and most of that was, well, garbage (Why do Arduino users torture each other with bad code? )

Anyway, I spent a day writing what I think is a proper library for the LED&KEY.

I've attached a demo that shows off the features:
-- write segments to any column
-- write a hex digit to any column
-- write a character to any column (limited by 7-segment displays)
-- write the state of any led -- or all at once from a single byte
-- fill the 7-segment displays and leds with desired pattern/state
-- write a string (limited by 7-segment displays)
-- write a decimal value (left justified)
-- write a right-justified decimal value
-- write a fixed-point decimal value
-- write variable- or fixed-width hex value
-- write variable- or fixed-width binary value
-- read buttons

If anyone finds a problem with the library, please let me know.

I have ordered the version with eight 7-segment displays and 16 buttons. Will post code for it when it arrives and I've had time to play with.

Code updated: 19 DEC 2019

AGCB

Jon
I got the idea to try to make use of this thing from this video
part 3
https://www.bing.com/videos/search?q=youtube+clough42+electronic+lead+screw&&view=detail&mid=2B6239CA4D7F38750E1B2B6239CA4D7F38750E1B&&FORM=VDRVRV
Not to do the exact thing but to be able to switch to read several different outputs by using the buttons, indicating LEDs and 7segs.
Thanks
Aaron

David Betz

JonnyMac wrote: »

I have ordered the version with eight 7-segment displays and 16 buttons.

Where did you find one with 16 buttons? I could only find ones with 8.

JonnyMac

@Aaron That guy did a nice job on the case. I do a lot of coding for escape room puzzles and thought this board would be a good electronic lock interface. My problem with most of the Arduino code I found is that it was just fragments, not a full driver that would allow a new programmer (I'm not) to use the board to its full potential -- and do it easily. I think you'll find my driver does that.

@David It's an eBay find. If you do a search on TM1638 (the driver chip) you'll find a bunch. Here's the one I bought (I tend to stick to US suppliers):

-- https://www.ebay.com/itm/8-Bits-LED-Digital-tube-Module-Keyboard-Scan-and-Display-Module-TM1638-MCU/333348385691

This version lacks the discrete LEDs of the smaller one -- that's okay with me.

David Betz

Thanks, Jon!

JonnyMac

Today I received a TM1638 module marked JY-MCU that uses Red/Green LEDs, so I have modified my driver and demo to accommodate it. The new code is in my original post.

JonnyMac

After working with the TM1637 for a couple days I went back to the TM1638 and made some improvements
-- str() is faster and handles decimal points appropriately
-- wr_leds() and paint_leds() are faster

Updated code is posted above.

wmosscrop

Hi Jon -

Have you tried updating your object to work with the P2?

I've had success with the display, but cannot read the buttons, whether or not I do a pullup resistor on the DIO line. It looks like the P2 is sinking the current from the pullup and not allowing the line to go high.

Thanks,

Walter

JonnyMac

Actually, I may do that today. I have been busy with smart pins the past few days. Smart pins can do SPI, too, but I will use the P2 version of my P1 SPI (bit-bang) driver as it's plenty fast (tested up to 10MHz with MAX7219 display).

wmosscrop

Found that my issue was that I needed to use PINFLOAT() on the DIO pin. Now I see the buttons.

Still looking forward to your driver. Mine is wonky.

JonnyMac

Got it working! I had trouble with the buttons, too, but mine was an error having to do with reversing the bits in PASM2.
Posted here:
-- http://forums.parallax.com/discussion/171327/p2-tm1638-driver-and-demo/