How to ground a pin

Hi all,

Im using this guys project as a guide line for my own.

So far i haven't been able to make the robot work the way it suppose to, when i turn off the transmission the robot rotates as it should, but when i switch the transmitter on the robot starts to drive in a seemingly random direction.

So now im trying to troubleshoot what is wrong.

Ive checked the circuit and the antenna, and the both seem to work as they should (and the circuitry is ok). i think that the Arduino wont calibrate properly and that is why it can't track the transmitter.
Im not sure that i ground pin 11 as i should.

Is there a difference if i ground this pin to the GND pin on the Ardino itself or i need to ground it externally, and if i need to ground it externally how can i do it without connecting to the Arduino.

Im not using the bot chassis as the guy dose, im using 2 360 servos, breadboard, UNO, external power to the servos and 9v battery for the Arduino mounted to a wooden chassis.

The other thing that im wondering about is, that maybe when i disconnect the Arduino from the battery it losses all the calibration values.

If you got any other ideas why it wont work ill appreciate it a lot if you share your opinion!

Im lost at the moment, trying to figure what is wrong for about 2 weeks now.

The other thing that im wondering about is, that maybe when i disconnect the Arduino from the battery it losses all the calibration values.

Unless they are stored in EEPROM then yes you will.

Im not sure that i ground pin 11 as i should.

How do you thing you should ground is?

What we need to know is what you have actually done not what you were following.

From the code i understand that the valuse are stored in the EEPROM (so i get that the values for the calibration are not lost when i disconnect the power form the board).

Ive done almost exactly what the guy did, build the antenna and the circuit that connects the antenna with the receiving walkie-talkie to the Arduino.

The diffarence is that he connected the Arduino to the Boe-Bot chassis (to power the servos of the bot) and grounding pin 11 through the bot chassis and ive connected pin 11 to GND pin as i dont use the bot chassis.

So im asking, is there a difference in how i ground pin 11?

Why does he ground pin 11?

So im asking, is there a difference in how i ground pin 11?

Pin 11 on what?
There is no ground on pin 11 on the Arduino on that physical layout diagram.

In any collection of circuits you must connect all grounds together in order for them to work together unless you are using opto isolators..

Grumpy_Mike:
Pin 11 on what?
There is no ground on pin 11 on the Arduino on that physical layout diagram.

He seems to be using pin 11 on the Arduino as an input to switch it into some calibration mode.

Russell.

In which case a wire between pin 11 and the ground pin on the Arduino will do it.

Tnx, so im guessing that grounding pin 11 to GND pin on the Arduino isn't the problem :slightly_frowning_face: