I am doing a microcontroller (89c51) based project and the peripherals used are ADC804, LCD and a keypad. The input to the ADC is both negative and positive voltage so does anyone know how can u make ADC read a negative voltage. Some of my friends told me that i can add an adder cicuit to the input of the ADC? , Does anyone know how to do that .
And how to interface these peripherals with the 89c51 so that i can give it for fabrication (if with detailed intefacing diagram will be really helpful)
Some one please do help me
Connect a 10k from Vcc to ADC input.
Connect a 10k from ADC input to GND.
Let us say your micro works at 5V.
The ADC input is thus 2.5V without an input.
All + volts are above 2.5 and - volts are below 2.5 volts.
Thus you can measure +- 2.5 V