ht1668 led driver

[nikolas77]

Hello, I have an electronic device that does not turn on the display
and uses the above integrated
I just want to ask for confirmation if I buy a new one do I
have to reprogram it? or does not need planning?
thanks in advance

 

[KlausST]

Hi,

Do you have a link to the datasheet at the manufscturer's site?

Did you read the datasheet?
Did you read additional documents provided by the manufacturer?

... this is what I'd do if I need to know this

Klaus

 

[FlyingDutch]

I just want to ask for confirmation if I buy a new one do I
have to reprogram it? or does not need planning?
thanks in advance

Hello,

are you sure that the cause is not related to power supply unit (did you measure supply voltage)? Yes this IC is programmable, so one make conclusion that somewhere in this device is microcontroller (and this microcontroller may be defective). So you cannot be sure that replacing this IC solve the problem.

Best Regards

 

[nikolas77]

thanks both for your interesting answers
I have check the power supply
this is the easy way
just in my case there are two pcb circuits and the two have microcontrollers and i dont know which from two has the problem
this is the link with the pdf file http://www.artschip.com/pdf/HT1668.PDF
from your experience if i have vdd voltage must the two digit of seven segment of my device light ? or is there a way from the manual to check if the
ht 1668 has fault ?

 

[KlausST]

Hi,

Thanks for the link.
As far as I can see, this is not a "programmable" device like a microcontroller.
I´d rather call it "configurable". It can´t do anything useful as standalone device.
It always needs a microcontroller or similar to tell what to do.

So: you can replace it without the need for anything else to do.

Klaus

 

[nikolas77]

aaa very nice mr klaus
just why tell in the pdf recommended software flowchart ? as attach file
that is not mean when you buy this ic must programm it according with bellow instructions ?

 

[KlausST]

Hi,

the flow chart tell how the microcontroller needs to communicate with the display driver.

Obviously the microcontroller needs to send some data to the display driver, otherwise the display driver does not know what to display.

Klaus

 

[nikolas77]

that is, these commands are already in the microcontroller on the other board correctly; so I do not have a problem I will take the same ic HT1668 and I will change it maybe it's wrong
Just mr Klaus two last questions if you can answer me of course
1. if we consider that the microcontroller is to blame and does not send the STB, DIN, CLK signals to HT1668 then again the result will be as now it will not light up on the screen properly and the machine will be completely dead and second at the point in pdf file which says When IC power is applied for the first time, the contents of the Display RAM is not defined; thus, it is strongly
suggested that the contents of the Display RAM must be cleared during the initial setting.
how can i do this sir?

 

[EliseFuller]

thanks both for your interesting answers
I have check the power supply
this is the easy way
just in my case there are two pcb circuits and the two have microcontrollers and i dont know which from two has the problem
this is the link with the pdf file http://www.artschip.com/pdf/HT1668.PDF
from your experience if i have vdd voltage must the two digit of seven segment of my device light ? or is there a way from the manual to check if the
ht 1668 has fault

was your issue resolved?

 

[nikolas77]

no

 

[KlausST]

Hi,

1) if the microcontroller is defective, then changing the display controller won't make it work.
2) the display content should be cleared/updated by the microcontroller

Klaus

 

[nikolas77]

i want to ask something last
before order this ic
if I measure with the oscilloscope and I do not see any signal in STB, DIN, CLK as show the figure of pdf file when give power supply
the problem is the microcontroller and not the led driver ic correctly?

 

[betwixt]

The microcontroller generates those signals in its software so if the signals are missing either the microcontroller is faulty or something else is preventing it running properly. Consider that if the software can't run, the signals will not be present even if the microcontroller is good. It is possible it is stuck in a reset condition or waiting for some other signal before it sends the initialization to the HT1668.

Brian.

 

[danadakk]

The MCU has bi-directional communications with the display controller,
so you cannot definitively conclude what part is bad with no activity
on those lines without further info on the display controller and how it
manages keyboard scanning.

Regards, Dana.

 

[betwixt]

There is no substitute for a logic analyzer in this situation, looking at the waveforms (if they exist at all), comparing them with the timing diagrams on the data sheet and decoding the data will almost certainly lead to the reason it doesn't work.

You possibly can follow data with an oscilloscope if it has storage and can be triggered on the start of data but it would be difficult.

Brian.

 

[KlausST]

Hi,

* there are cheap USB logic analyzers like the LA1010 (and family)
* or something like an ADALM2000 that also combines the logic anlyzer with a (small) power supply, analog scope, signal generator....

Both of them are good for beginners and worth the money - in my eyes.

Klaus

 

[danadakk]

$10 logic analyzer, but keep in mind inputs not protected. Uses either
SALEAE and USBEE AX software. And sampling rate not very high. Fine
for I2C low speed.

USB Logic Analyzer Device Set Compatible to Saleae 24MHz 8CH for ARM FPGA M100 783710087560 | eBay

Logical analyzer supports both: SALEAE and USBEE AX (logical part only). 1, Saleae, Logic, 24M, 8CH logic analyzer host 1. Product weight: 50g (including SALEAE, USB line and 10 DuPont lines). 1 x 24MHz 8CH USB Logic Analyzer 24MHz 8 Channel Compatible to Saleae ARM FPGA M100.

www.ebay.com

as one example


Regards, Dana.

 

[nikolas77]

thanks a lot for your helpful answers

--- Updated Feb 1, 2022 ---

sorry i'm asking again just because i'm too busy with the repair and not with microcontrollers and software i would like to ask to be sure
if I give power to the device that does not turn on anyway and use the usb logic analyzer l1010 suggested by Mr. klaus
to understand I will connect to the three channels of the usb logic analyzer the signals I mentioned above of the led driver to monitor their status without creating an additional problem on the boards;