Problem getting CD4514BE to work

[Alek]

I got my CD4514 today for my LED cube project and I wanted to test it to see how its connection and does it actually work.

Following the datasheet, I connected Vdd(24) and Strobe(1) through a 1K resistor to +5V. I connected Vss(12) and Inhibit(23) to GND.

From output pin 9 - Ouput S1 through a 1K resistor I connected a 3mm LED.

Now, from +5V I connect a 1K resistor to input pin 2 - input Data 1 - A

By the truth table this will result in output S1 going high but in my case the led diode does not light up. When I toggle the +5V on and off the led sometimes dims but doesn't light continuously.

Am I connecting something wrong ?

 

[ericgibbs]

I got my CD4514 today for my LED cube project and I wanted to test it to see how its connection and does it actually work.

Following the datasheet, I connected Vdd(24) and Strobe(1) through a 1K resistor to +5V. I connected Vss(12) and Inhibit(23) to GND.

From output pin 9 - Ouput S1 through a 1K resistor I connected a 3mm LED.

Now, from +5V I connect a 1K resistor to input pin 2 - input Data 1 - A

By the truth table this will result in output S1 going high but in my case the led diode does not light up. When I toggle the +5V on and off the led sometimes dims but doesn't light continuously.

Am I connecting something wrong ?

hi Alek,
The 4514 is CMOS, you must connect all the address lines to either 0v or Vss, never leave CMOS inputs floating.

Thats A0,1,2,3...... pins 2,3 21,22

BTW: its got to be a 4 bit address on A0 thru A3, thats selects which output is enabled.

The easy way to check is to connect all the address pins to 0V, then the output O0, pin #11 is enabled.

 

[crutschow]

Vdd should be connected directly to the +5V, not through a resistor.

 

[Alek]

Thanks for the quick reply. Could I connect a resistor from each input to 0V or Vss and when I want to input data on a specific input I'd input it directly to the pin ?

 

[Alek]

My idea is to use the 4514 to control this led cube :

https://www.electro-tech-online.com...allel-output-port-only.96374/?highlight=4x4x4

 

[ericgibbs]

Thanks for the quick reply. Could I connect a resistor from each input to 0V or Vss and when I want to input data on a specific input I'd input it directly to the pin ?

hi,
Use say 4.7K pullup resistors to all the address pins, by switching all to 0V it addr =0 and all high addr 15.

As Carl said, NO resistor to pin 24 to Vss.!

 

[ericgibbs]

My idea is to use the 4514 to control this led cube :

https://www.electro-tech-online.com...allel-output-port-only.96374/?highlight=4x4x4

Do you have a drawing to post.?

 

[Alek]

Ok, I see my mistake. Can you give me some sample schematic for connecting input outputs on a CMOS IC?

 

[ericgibbs]

Ok, I see my mistake. Can you give me some sample schematic for connecting input outputs on a CMOS IC?

hi,
Post your project drawing and we can help.

 

[Alek]

To tell the truth I don't have a project drawing at the moment. I've simulated the sample circuit in EWB but the schematic got lost in reinstalling wine

My idea is to use the PC's parallel port with the combination of the 4514 to control a 4x4x4 led cube.

I have the cube finished. The sections are controlled by Gnd and the individual (16) leds at the bottom with Vcc from a source that's controlled with a NPN transistor which is controlled by the 4514

It sound confusing... I will draw the schematic that I have in my head in about 30min.

 

[ericgibbs]

To tell the truth I don't have a project drawing at the moment. I've simulated the sample circuit in EWB but the schematic got lost in reinstalling wine

My idea is to use the PC's parallel port with the combination of the 4514 to control a 4x4x4 led cube.

I have the cube finished. The sections are controlled by Gnd and the individual (16) leds at the bottom with Vcc from a source that's controlled with a NPN transistor which is controlled by the 4514

It sound confusing... I will draw the schematic that I have in my head in about 30min.

OK,
which pins of the paraport are you planning to use.?

Also are you running Windows XP.?

 

[Alek]

2 through 9 - 8 the 8 data outputs.

No I'm not using Windows, I'm using GNU/Linux on all of my machines. I have a pretty good idea how to code the control program that will drive the led cube

 

[kpatz]

I got my CD4514 today for my LED cube project and I wanted to test it to see how its connection and does it actually work.

Following the datasheet, I connected Vdd(24) and Strobe(1) through a 1K resistor to +5V. I connected Vss(12) and Inhibit(23) to GND.

Connect Vdd directly to +5V, and Vss directly to GND with no resistors.

For inputs you're not using, you can tie them directly to Vdd or Vss, no resistors needed. As others have said, don't leave any inputs unconnected. The only time you need resistors on inputs is for pullup/pulldown purposes when you're providing input to the pin from something that only provides +5 or 0V but not both.

From output pin 9 - Ouput S1 through a 1K resistor I connected a 3mm LED.

How is the LED connected? Anode through resistor to S1 and cathode to GND will cause the LED to glow when S1 is high. Cathode through resistor to S1 and anode to Vdd will cause the LED to glow when S1 is low.

You said you connected data 1 (A) to Vdd. Did you connect the other data pins to Vss? You'll need to in order for S1 to go high.

 

[ericgibbs]

The only time you need resistors on inputs is for pullup/pulldown purposes when you're providing input to the pin from something that only provides +5 or 0V but not both

hi kpatz,
There is another time I would recommend pu or pd resistors, that is when using CMOS ic's that will have floating inputs when the 'project' is unplugged from its driving source.

eg: a PC paraport output, he should choose pu or pd, so as disable the project drivers when unplugged.

 

[Alek]

As I said, I didn't connect the other input pins. The led is connected like this :

Output pin S1 >> Resistor >> LED Anode > LED > Led cathode > Gnd

 

[ericgibbs]

As I said, I didn't connect the other input pins. The led is connected like this :

Output pin S1 >> Resistor >> LED Anode > LED > Led cathode > Gnd

hi,
The other pins A0 thru A3 are not data pins, they are address pins.

 

[Alek]

The datasheet said, Data1, Data2, Data3 and Data4 for A, B, C and D respectively

 

[ericgibbs]

The datasheet said, Data1, Data2, Data3 and Data4 for A, B, C and D respectively

I have my databook here and it says A0 to A3 address inputs.

Providing we both know that they are address lines , used to select an output pin.

BTW: for reference only, the 4515 is the 'sister' ic to the 4514, with low going outputs.

 

[Alek]

I know about the 4515. I really freaked out when I wasn't able to get the IC working. I'll try tomorrow with getting GND to the rest address pins. My supplier tolled me that this is the last chip, and that they will be receiving a new shipment at the end of October. I really can't wait that long

 

[kpatz]

As I said, I didn't connect the other input pins. The led is connected like this :

Output pin S1 >> Resistor >> LED Anode > LED > Led cathode > Gnd

Ground out the remaining address pins, and then you should see S1 go high.

If you connect all 4 address pins to ground, you should see S0 go high.

hi kpatz,
There is another time I would recommend pu or pd resistors, that is when using CMOS ic's that will have floating inputs when the 'project' is unplugged from its driving source.

Good point, though I was referring to using resistors on inputs hard-wired to Vdd/Gnd as opposed to inputs fed from "something" such as a switch or other source that might leave the input floating.

So the OP will want pull-up or pull-down resistors on the input pins going to the parallel port, but for the purposes of testing with the pins hard-wired, the resistors aren't needed.