may i know what does it mean by "Serial" will go over the USB ?
And what is the difference to Serial1 ? ( in terms of how it works, what the results would in terms of speed, etc )
I ran into trouble because the GPS sensor and the air quality sensor by plantower both uses SoftwareSerial .
in R4 are there SoftwareSerial and SoftwareSerial1 ?
ESP32 S3 has three serial ports, yes ?
The Uno R4 WiFi has two serial interfaces
The one named Serial communicates with the PC using the USB cable plugged into the R4. It is used to upload code and to interact with the Serial monitor in the IDE
The other one, named Serial1, uses pins 0 and 1 of the R4 to communicate with devices, such as a GPS, attached to those pins.
To use Serial1 just refer to it by its name as you would Serial. For instance, Serial1.begin(115200); Serial1.read(); etc
I don't know whether a special version of SoftwareSerial is needed for the R4, but I expect it would be
On a regular Uno you cannot sensibly use 2 instances of SoftwareSerial
So this would not work ? ( on R4 )
SoftwareSerial pmsSerial1(2, 3);
SoftwareSerial gpsSerial(0, 1);
So this would not work ?
( i am traveling right now without my kit so i can't test )
On which board could i make this work ?
What happened was, using R4 Wifi,
when running PM2.5 plantower sensor and GPS sensor at the same time ;
If i declare pmsSerial.begin(9600) FIRST, the GPS part will not output anything
if i declare gpsSerial.begin(9600) FIRST , the PMS(pm2.5) part will not output anything So i applied this
https://docs.arduino.cc/tut.../communication/TwoPortReceive/
on arduino Uno R3 and it worked but when i apply it to R4 Wifi , it says
"class SoftwareSerial' has no member named 'listen'. "
SoftwareSerial gpsSerial(0, 1);
definitely won't work, nor would it work on a normal Uno even if it compiles
If you need multiple independent serial interfaces then get something like a Mega. It has 4 hardware UARTs
When you say "normal uno", does R4 Wifi considered as "normal uno" ?
No. I had the Uno R3 in mind
Arduino have clouded the water by naming a number of partially compatible boards "Uno". It is even worse with the "Nano"
So using R4 it is supposed to work I assume ?
SoftwareSerial pmsSerial1(0, 1);
SoftwareSerial gpsSerial(2,3);
Serial.begin(115200);
Serial.read()`
`Serial1.begin(115200);
Serial1.read()`
4 serial ports
Seems expensive compared to
3 serial ports
Do not use SoftwareSerial on pins 0 and 1 of any Uno
As previously explained you can just use Serial1 on pins 0 and 1 of an R4. If SoftwareSerial works on other pins of the R4 then connect one serial device to pins 0 and 1 and use Serial1 and the second device to the pins used by SoftwareSerial
One thing to take into account could be that SoftwareSerial does not work reliably, if at all, at 115200 baud on the Uno R3 so may struggle at that baud rate even on an R4
No, the implementation of SoftwareSerial for the Arduino UNO R4 is different and does NOT allow multiple instances on different pins.
You can only have one SoftwareSerial on the Arduino UNO R4 and there are also limitations on the pins you can use for the RX.
Guglielmo