Crowpanel 5" uart0 level issue
Hi,
I have a 5" crowpanel display connected via uart0 with an arduino mega2560 board. I measured the levels on the uart0 and the high level is correct at 3.3v while the low level is about 1.4-1.5V. The data exchange works but sometimes it loses the signal. As an interface between the serial1 of arduino and the uart0 I use a converter such as TXS0108EPWR from texas.
The output levels of the converter without the uart0 connected are correct and go from 3.3V to about 0V. When I connect the uart0 the low level does not go lower than 1.4-1.5V as you can see from the attached image. Is there a solution or is it ok like this? With the low level at 1.4V is the connection reliable?
Thanks
Alessandro (Italy)
Comments
Hi albova，
Thank you for reaching out.
Our technical support team is currently looking into your issue. Please be patient, and we will get back to you as soon as possible.
Best regards,
Hi albova，
Normally, if connected directly, there will be this low-level voltage issue at 1.4V, which may cause data distortion.
You can try adding a pull-up resistor on the B port of the TXS0108E (the side connected to the Arduino Mega2560’s 5V). This may help ensure signal level stability. Then, check the power supply voltages:Make sure VCCA of the TXS0108E is connected to the working voltage of ESP32S3 (3.3V); VCCB should be connected to the working voltage of Arduino Mega2560 (5V). Additionally, make sure the OE pin is connected to VCCA to enable the level shifter.
Let us know if you need any further assistance.
hi,
the OE pin is connected with 10 Kohm to Vcca and the uart0 pins of the display are connected to both gnd and 3.3V. I tried to insert a 10 Kohm pullup resistor on tx1 and rx1 of arduino mega but no results are seen. Do you have any other solution?
Alessandro
Hi albova，
Please change the diagram according to the image below.