I would like some suggestion regarding power supply to the Nextion. First, some background:
I have a 10” capacitance model that is less than a year old. Few months ago, it started having difficulty programming (via SD card). It’d require a few retries before successfully programmed. When it failed, it'd reset itself at the beginning or the middle of the programming cycle. Gradually, the problem worsen. Now, the unit has become a brick. The screen just keeps flashing when power is applied.
Tech support told me that the LCD driver is likely damaged, by inadequate current supply. It’d be costly to send it back to the factory for repair.
I had been powering this 10” screen from a USB hub which is powered by a 48W adapter. Usually, the hub only has one or two other low power USB devices plugged in. The Nextion was plugged into the hub’s QC3.0 power-only port. So, I believe delivering 5V @2A was not an issue.
My questions are:
- Was it safe to use a QC3.0 port for power?
- If not, what’s best to use?
Thank you.
I agree with Tech support. What does the display require? This is probably not what you have available.
The specs for the 10” model recommends 5V @2A. With a typical consumption of 800mA (at max brightness).
I’m pretty sure the QC3.0 port is capable of delivering the “power” (wattage wise). The question remains is that a QC3.0 port can vary its output voltage and current up and down. In our case, the Nextion is actually leaving the data lines of the USB cable open, thus no negotiation to adjust the voltage. Theoretically, it should just stay at 5V. Then it needs to be able to output up to 2A at 5V during peak consumption—that I’m not sure about whether it can. When charging my phone, I have seen the QC delivering 1.5A @9V.
Am I making sense?
Hopefully, someone with experience of the Nextion AND QC3.0 operations can explain whether the two together make a safe combination.
With that setup, it won’t work. A typical USB port provides about 0.5A at 5V. Additionally, you’re disagreeing with their tech support, who likely has more experience than both of us combined. Instead of guessing and risking frying another device, just get a recommended power supply. It also helps if links are posted to technical information on the parts in your project.
Yes, it is safer to supply the power from a simple fixed 5V 2A adapter. I do like to know whether or not that QC3.0 port was the culprit. Electrical specs is here if interested.