I am trying to use the TLC5948A LED driver and it does not seem to operate per the data sheet. Is there anybody who has successfully used this part and can offer any help. I have tried to get help from technical support, but have been unsuccessful in speaking with anyone familiar with this part. The main issue that I have can be summarized with the following code example:
// Bits 127 - 112 (Function control, global brightness and Dot Correction) // g_socpaled_cntrldata.out7.all = 0b0000000000000000; // No bits set, no display g_socpaled_cntrldata.out7.all = 0b0000000100000000; // Just this bit set (shows as blank) display repeats // g_socpaled_cntrldata.out7.all = 0b0000001000000000; // Just this bit set (shows as bc6) display on, but does not repeat // g_socpaled_cntrldata.out7.all = 0b0000010000000000; // Just this bit set (shows as bc5), no display // g_socpaled_cntrldata.out7.all = 0b0000000010000000; // Just this bit set (shows as repeat), no display // g_socpaled_cntrldata.out7.all = 0b0000000001000000; // Just this bit set (shows as tgmrst), no display // g_socpaled_cntrldata.out7.all = 0b0000000000100000; // Just this bit set (shows as espwm), no display
Any help offered would be appreciated.
I'm Narisawa and in charge of LED driver.
I attached TLC5948A sample code which is C base and that flow chart too.
Could you please try to this?
If you need any, please let me know.
Thanks and best regards
Thank you for your quick response. I will look at the information very soon. The register map and sample code should be very helpful.
I see that you used a PIC processor for the example, can you tell me which processor and compiler you used to test the code?
If I have more questions (or resolve my issue) I will let you know on this "thread".
I'm sorry my late response.
Processor is PIC16F690 and compiler is HI-TECH,but I'd like to push MSP430 to you...
I attached a file which some functions are explained.Please refere them to make program.
I received the response from you regarding the PIC processor and compiler used in your code and appreciate the information. It would also help a great deal if I could see your schematic.
I will look at the pdf file you sent and but in the interim there is some additional information:
1) I understand your code correctly you are using an output from the Microcontroller to generate the GSCLK (also called BLANK in the software) signal. It also appears that you are halting the GSCLK when loading data or control information. Is this necessary? I am using a 33 MHz Oscillator on my board for GSCLK and not stopping the GSCLK when loading data.
2) I have 3 of the TCL5984A’s on my board in a “daisy-chained” arraignment. I am using the same output routine to send control and grayscale data. I can send zero data to all the grayscale latches except to the least significant bit of the last latch I set to a one. When I do this I can see all the outputs are 100% off on all three chips except the last output of the first chip has a very small signal to the OUT0 pin. To me this proves that I am able to send bits 0 thru 256 three times with a bit getting missed. Why would using the same routine cause bit issues with the control data?
My only explanation at this point is that your system runs significantly slower than the one I am using. I believe that my system (software and hardware) conforms to the data sheet specifications, but does not operate as the data sheet indicates.
Any help anyone could offer would be appreciated.
I now know what the problem is! It was a software error (of course) and the chip works exactly per the data sheet. The error was in the way I had set up the control structure.
I thank you for your help! Your code and support was great!
If you need any help, please let me know any time.
I'll support you until you succeed.
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