I work at an educational institution and we use Parallax LCD’s (link to product) (link to data sheet) along with Arduino Uno’s (R3). We have been using the same sample code for years without issues but this year encountered undesirable behaviors with newer IDE versions. I have attached the sample .ino we use, but it may not be very useful without a comparable LCD to connect to.
The behavior we are seeing is that when using the SoftwareSerial library instead of the regular TX pin, text does not seem to print correctly and the cursor location seems to move around so that characters end up where they shouldn’t be. Reverting to IDE 1.8.9 fixes the issue, and 1.8.10 and 1.8.12 definitely have it. This is across dozens of computers and Uno boards so I’m pretty confident the issue is tied to the SoftwareSerial library and not another factor.
I checked the GitHub listings for known bugs relating to SoftwareSerial and I don’t see anything that looks like this in open issues.
For right now, we can just revert versions to 1.8.9 and be OK.
I am trying to figure out
-if this is actually a bug OR
-some kind of change in how the library works that makes this expected behavior and we need to code differently OR
Basically I’ve done as much testing as I can think of, and I am confident the issue relates to either changes in the IDE in general or SoftwareSerial.h in particular between 1.8.9 and 1.8.10. I just don’t know what to do next to further narrow this down or what would be most helpful to report as a bug. Any ideas?
LCD_Sample_Code.ino (2.26 KB)