<![CDATA[AtomS3U serial communication from Atom but not to Atom.... Why?]]>I am plugging an AtomS3U into a USB port of my Windows 10 laptop and I want to have the AtomS3U emulate my microscope. To do that, I need to send and receive serial characters.

Completely new to the AtomS3U and UIFlow2, I have just recently managed to get my first progam into the AtomS3U and that works: able to change the colour of the internal LED.

Now, I want to be able to read and write data on the PCs USB (COM9) connector.

To test, I am successfully using Putty to talk to COM 9. (115200 baud, 8 data bits 1 stop bit, no parity) Flow control. I have tried with and without XON/XOFF.

I see Hello World messages from the Atoms3U showing that I have the correct COM port and that the AtomS3U is programmed and working. However when I type something I never see any data available message showing communication works from PC to Atom.

Why can I communicate in one direction only?

HelloWorldUART.PNG

]]>https://community.m5stack.com/topic/6928/atoms3u-serial-communication-from-atom-but-not-to-atom-whyRSS for NodeTue, 12 May 2026 23:31:23 GMTSat, 26 Oct 2024 00:06:12 GMT60<![CDATA[Reply to AtomS3U serial communication from Atom but not to Atom.... Why? on Fri, 01 Nov 2024 08:16:08 GMT]]>Hello @ivanurwin

the communication between PC and M5AtomS3U happens via native USB (without an external USB/Serial IC) which cannot be used with UIFlow2 UART blocks. UIFlow2 UART blocks define GPIOs for RX and TX (among others) which do not exist for a native USB connection.

The only UIFlow2 block I see which will read data from the PC via a native USB connection is prompt for text with message.

Thanks
Felix

]]>https://community.m5stack.com/post/26918https://community.m5stack.com/post/26918Fri, 01 Nov 2024 08:16:08 GMT<![CDATA[Reply to AtomS3U serial communication from Atom but not to Atom.... Why? on Mon, 28 Oct 2024 04:06:31 GMT]]>Hi @ivanurwin
It seems your computer is sending serial data when the device logic just enters the "Sleep 5 seconds". Try to delete this block to see if it works.

]]>https://community.m5stack.com/post/26870https://community.m5stack.com/post/26870Mon, 28 Oct 2024 04:06:31 GMT