how to program led display (16*32) using 8051

[kiran bhat]

hi guys
i am kiran bhat. i have purchased one led display. i dont know how to program it. there is no data sheet available for the display.
i am using p89v51rd2 controller.

the display consists of shift register 74hc595 and a octal bus driver 74hc245. there are two bus connectors of 16 pins.
the pin details available on the display is as follows

1 - OE
2 to 8 - GND
16 - A
15 - B
14 - CLk
13 - AT
12 - RD
11 to 9 - No description

please give me some solution for the problem.

 

[barry]

Why would you buy a display with no data sheet?

 

[kiran bhat]

hi Barry
thank you for replying. the reason why i purchased that display is little bit complicated to explain. if you have any idea on moving led displays please share it.it'll be very helpful to me.

 

[barry]

You give us no usable information. the OE and CLK pins function are obvious, the rest, who knows? You don't even have a schematic? Apparently you shift data into the shift register, but I have no idea what A, B, AT, and RD do. Good luck.

Next, buy something with documentation

 

[kiran bhat]

hi barry

after analyzing the display hardware i found out all the pin descriptions, but now i am struggling in programming please help.
there are mainly 4 ic's are used 1)shift register (74hc595), 2)octal bus driver (74hc245), 3)decoder/demultiplexer (74hc138) and 4)power ic (contains 2 P-channel MOSFET) (4953)

pin description:
1. OE - out put enable (active high)
2. CLK - clock for shift register
3. LAT - clock for storage register
4. RD - serial data input pin.

please help me in programming. i have drawn schematic in Proteus, its full complete i am attaching that and as soon as i complete it I'll post the full schematic.

thank you

 

[kiran bhat]

hi barry
here is the schematic of the display.

 

[jayanth.devarayanadurga]

Zip and attach Proteus file. How are you sending data? There is no uC in the design.

 

[pasicr]

Hi Kiran
can you attach for me some images from your led display, front and back side?
probably this is one color led module?
best regards

- - - Updated - - -

Hi Kiran
can you attach for me some images from your led display, front and back side?
probably this is one color led module?
best regards

 

[kiran bhat]

hi
the details of the led display with images, datasheets and circuit is attached please go through it.

 

[pasicr]

Hi Kiran,
thanks for images,
that is standard P10mm outdoor one color RED led modules, price app 9 USD,
this module use HUB12 signal card, the price for this card is app 5 USD, also you may personaly make PCB HUB12 without problem, you need only one 16pins connector and one 74HC245,
only search on google for HUB12,
Kiran, dont spend a time with making own command system,
you may buy for several USD proffesional command board and use this module in real capacity,
for example Asynchronous led sign control card JD20KU, price is only 12 USD,
best regards

 

[kiran bhat]

hi pasicr
thanks for the reply and it really helped me. Hub 12 is already present in this board. Now i need is jd20ku that also i'll purchase online. but i want to know how to write the command set for this display ,its just i am curious i just want to display at-least a single character on this display through 8051 how can i do that.

 

[pasicr]

That is complicated case, specialy scaning frequency,
this module use 1/4 scan method, that mean one pin from shift register 595 controll 4 led's,
you must controll via 138 witch row is active, also you must control many 595 via one serial input...
many things for control,
if you are begginer I think is not easy for you,
this need programming experiences....

me again,
look this
https://www.adafruit.com/products/1072
you need something like this, but that is full color SMD led module, more problem for control...

 

[kiran bhat]

hi
the deatils are attached please go through it.