Help/Clarification

[africanman1961]

Hello olkal
Thank you for this project. Please note, I am a beginner.
My question is to do with the wiring of the lcd, specifically I2C, Circuit_CG_scale_r3.fzz refers. you have a wire running from 16 on the arduino to the positive and negative battery terminals. Please could you tell me what this is for and if it is necessary for connecting to an I2C LED.

Thank you
Mark

[olkal]

Do you mean the connection from Arduino pin A6? If so, that is for measuring the battery voltage. If you don't want to show the battery voltage on the LCD you can omit the wiring to pin A6 and comment out the line 76 in file CG_scale.ino: displayVoltage();

[africanman1961]

Hello Olkal
Thank you very much for answering my question. I understand your explanation. I would like to include the battery voltage display on my scale.

Talking about this same wire to pin A6, I note on the schematic a 10k resistor coming off the positive battery wire and a 4.7k resistor coming off the negative battery wire. Both connect into the wire going to the A6 pin. Forgive me, but will this not cause a short circuit?

Thank you
Mark

[olkal]

Hi!
No, the 2 resistors tied to + and - is called a "Voltage divider" and it will reduce the voltage to input pin A6 from your 9V battery, this is required as voltages >5V can blow the MCU input pin.

[africanman1961]

Hi Olkal
Thank you very much for your reply. I am learning new things with this project.

Appreciate your help.
Mark

[africanman1961]

Hi Olkal

Please could you help, I would like to move the weight display to the top line and add one decimal place. Please indicate how I could do this in the sketch.

As always, appreciate your help,
Mark