hi wayne,
This is one option for the AD620 with a single +5V supply.
Note the test ramp is from -0.5mV thru +5mV, its IMPORTANT that a load cell bridge amp system can go below 'zero weight' on the display.
The below zero display is required so that the operator can be confident the weight on the scale is truly zero and not just the AD620/amp in a saturated state, showing 00.0kg
The program software will have to remove the small positive offset weight.
I also allow a 10% over weight on the Vout to the ADC input, again you want to display a weight over the 5Kg on some occasions. [ your load cell will also be rated for 10% over weight]
OK.?
E.
EDIT:
I should also point out the load cell will need some metal work to make a base on which you place the weights.
The 'weight' of this metal base will move the load cell mV output above zero, so the ZERO pot will need to be adjusted,