I Just received the 4.3 inch screen.
I hook it up to an usb to serial adapter and power it up.
The screen show a welcome display for 1 second and start to white out.
Now the screen is just white.
So I used the nextion editor and it was able to connect on it.
I was able to download the new software and firmware.
But the screen is always white!
I use the debugger from the nextion editor and the touch screen works. At least it returns data when I press the screen.
So what is wrong. Just wonder if that screen has been test for more than 1 seconds.
I did check the voltage and it is exactly 4.96V and the 3.3V reports 3.36V.
A frustrated guys who was waiting for that display.
Ok I used my oscilloscope and find out that the 100Mhz oscillator Y1 doesn't work. :-(
Now I just wonder where the clock for the STM32F cpu is from ?
I don't have special knowledge about the oscillator Y1, but I see that the 2.4" Nextion also has a STM32F (U2), but no U3 (ALTERA MAX II) and no Y1 (100 MHz oscillator). So it seems like the STM32F works without this Y1 oscillator.
I see in the datasheet of the STM32 that there is an internal 8 MHz RC oscillator. An external 4-32 MHz clock is optional. See page 1 and chapter 3.6 page 14.
Since I knew that the oscillator was the guilty one. I decide to resolder it just in case something was wrong. At my stupefaction that did the trick! ;-)
I'm now a happy guy.
I notice that the parts was soldered manually, resistors are not aligned exactly, so I suspect that some solder was not done properly.
Well After letting the display cool down. The crystal is still not working. So I will need to replace it. :-\
But at least I know that a new oscillator will work . And I could have that display working If I heat up the oscillator first. It is summer here so the temp is around 22 celsius inside my house.
If you use the USB 5V 500mA, it may not enough for the Nextion 4.3 or 5 , so try using the powerful 5V power for it...
First Post I said that the voltage at the display is 4.96V. I use a 5V 2A anyway.
If I power it up cold it won't work.
Then I use a lighter and heat the oscillator for half second and power it up. it is working for half hour until it cool down. Looks like it will run if the temperature is higher than ~27C. Last week we had a hot day (>30C) and it rans all day until the evening when the temperature drop.
I leave in Canada and it is july and the temperature yesterday night was around 13Celsius and it is now 20 Celsius and it is 23C inside my house.
I just wait to have enough electronic parts to order and replace the oscillator. For now like I said I just warming it and it is good for a short time.
my smaller 2.4 screens work fine and take my hmi project great
however the 4.3 just blinks using the same usb serial cable, will try to power it with more current than it supplies see if thats the probem
yes that fixed it, my adjustable vreg works fine to power the 4.3" @ 5v
You are not alone, I had the same problem and used a separate power supply to make it work :-)
if you use a separate supply from the ftdi you also need the ground from the ftdi cable to flash it
I used a breadboard to connect all grounds
So you mean there maybe some issue with the oscillator?
I think it won't be a common issue, this is the first feedback.
If any one come across such issue, let me know, thanks.
After 6 month of waiting. I order and install a new oscillator on my defective display.
And guest what ?
It is working !