Roomba Serial

I got an old Roomba 541 from someone, and I'm just playing around with it to see what I can do. I have it connected to an r3 Uno, using just Rx, Tx, and GND as indicated by others posts.

it seems no matter what commands I send, the bot just turns on and starts cleaning as if I'd hit the CLEAN button.

I've tried all the examples from this site, but it seems no matter what commands I send, the bot just turns on and starts cleaning as if I'd hit the CLEAN button.

Here's just one example I've tried:

void setup() {
 Serial.begin(115200);  
 Serial.write(128);  // START
 Serial.write(132);
 delay(50);
 Serial.write(140);
 Serial.write(0);
 Serial.write(1);
 Serial.write(62);
 Serial.write(32);
 delay(50);
 Serial.write(141);
 Serial.write(0);
}

void loop() {  
}

Is this your problem?

If you did not hear the “beep” or if Roomba started to clean around, you probably connected with a wrong baud rate. Please follow the instructions on Baud Rate configuration chapter before you continue

I ended up here for the same reason. It was the baud rate. I'm thinking of moving up to a 690. I was looking at the specs and it says that it does not have a manufacturer API. https://vachq.com/robot-vacuums/irobot/irobot-roomba-690 (under 'technology' toward the bottom). Someone also told me that it isn't as straightforward to mess around with the newer wifi ones, too. Is the 690 considered 'newer' because it has wifi?