Hi Guys,
I'm currently designing a digital pressure guage using a PIC16F88. Here's a quick overview of how it works: Positive (Guage) Pressure is measured via a small pressure sensor (output voltage changes with pressure linearly). The PIC reads the voltage via ADC reg and converts it to a 3-digit number. The number is then displayed on 4x 7-segment display.
I've tested the circuit on a prototype board. Works at treat. I'm now in process of soldering the components to a PCB. Before I do so, I need to check one thing.
I've used RA2 and RA3 as -VREF and +VREF. The voltage applied to these pins is produced via two simple Voltage dividers using resistors in series (as shown in attached image). Question: Do I need to a current limiting resistor before each pin? Or does the Micro use internal resistors?
I don't want to blow it up!
Thanks in advance
Tom
I'm currently designing a digital pressure guage using a PIC16F88. Here's a quick overview of how it works: Positive (Guage) Pressure is measured via a small pressure sensor (output voltage changes with pressure linearly). The PIC reads the voltage via ADC reg and converts it to a 3-digit number. The number is then displayed on 4x 7-segment display.
I've tested the circuit on a prototype board. Works at treat. I'm now in process of soldering the components to a PCB. Before I do so, I need to check one thing.
I've used RA2 and RA3 as -VREF and +VREF. The voltage applied to these pins is produced via two simple Voltage dividers using resistors in series (as shown in attached image). Question: Do I need to a current limiting resistor before each pin? Or does the Micro use internal resistors?
I don't want to blow it up!
Thanks in advance
Tom