I'm in strange situation where in the near future, I'll need serial access to my raspberry pi (via TRX, RXD and ground pins). In the mean time right now I'm trying to get the logins in order and make sure I can connect to the pi serially. The problem is when I connect to the pi serially, I get to the login, but I am unable to log in. I supply the correct user and the correct password, but it still won't allow me to log in. I've changed the default password on my raspberry pi as well as added a second user with a unique password to make sure that it wasn't just a problem with the pi account. Still no luck. What is more confusing to me is that if I plug in a USB mouse and keyboard, and use the HDMI output of the pi to gain a display, I am able to log in with the same credentials that I couldn't log in with over a serial connection.
I should also mention that this raspberry pi is a 3 B+, outfitted with raspbian buster and serial communication is enabled through
raspi-config. Also unfortunetly, I'm in a place where I can't connect the pi to wifi or ethernet to see if the problem persists if I try to ssh into the pi as well. Am I missing something in the configurations that would allow external devices to access the pi or something?
Could it also be that the pi hasn't been able to update? Since where I am, I cannot connect the pi to the internet, I haven't able to update it. The SD card I'm using was given the raspbian image yesterday, so not much time has passed since when the SD card had raspbian buster put on it to when I actually began to use it on the pi.
I take back the statement about not being able to connect the pi to wifi. Through hotspot, I was able to connect the pi and ping it from a computer also connected to the hotspot. However, I could not ssh into the pi, I had the same problem I had when trying to connect to the pi serially. Also, I tried updating the pi through hotspot, but my connection is not fast enough. So, still unable to tell if this is an update issue.