We are doing a project to display voltage & current values which are input from a 10k potentiometer into a PIC18f452 and outputting them into readable data on a LCD. We have been told that the chip can only detect and convert the voltage values but not the current's. Does anyone have any suggestions on how to find the current values?
We are doing a project to display voltage & current values which are input from a 10k potentiometer into a PIC18f452 and outputting them into readable data on a LCD. We have been told that the chip can only detect and convert the voltage values but not the current's. Does anyone have any suggestions on how to find the current values?
hi,
One way is to use a low value resistor in the current path and then measure the voltage across the resistor.
The resistor is usually in series withthe 0V line.
Thanks for the reply Eric! Actually what our project does is acting like a multimeter. We do not have external measuring devices to measure voltage, current or resistor values, just the chip itself. Is there any way that the chip could calculate the voltage and current values just by programming the pic18 to read the data inputs from the pot?
Thanks for the reply Eric! Actually what our project does is acting like a multimeter. We do not have external measuring devices to measure voltage, current or resistor values, just the chip itself. Is there any way that the chip could calculate the voltage and current values just by programming the pic18 to read the data inputs from the pot?
Ya we're using microchip's pic18F452 with A/D inputs. And yes we have exactly no idea how we're going to measure the current with no external measuring equipments. Thus our post here. Except that we know we're not supposed to use any external measuring equipments, other than for testing purposes to find out whether our circuit is accurate. Here's a schematic drawing:
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Also, can you explain what u meant by "it has to be done measuring the voltage between the pot wiper and 0V."? Do you mean measuring using a multimeter? I'm sorry for all the trouble coz all our teammates have no idea what's going on except for a bit of the programming.
We are doing a project to display voltage & current values which are input from a 10k potentiometer into a PIC18f452 and outputting them into readable data on a LCD. We have been told that the chip can only detect and convert the voltage values but not the current's. Does anyone have any suggestions on how to find the current values?
Thanks for the reply Eric. We're trying to measure the current running through each pot. Actually when the resistance of the pot is varied via the wiper/swiper, the current and voltage changes too right? Therefore all the changes must be concurrently displayed via our LCD. We are gonna try connecting: pin1 of the pot to ground, pin2 to PORTA aka the ADC input, and pin3 to 5V. I'll let you know the results once we've tried it out, about 2 days later. =)
Thanks for the reply Eric. We're trying to measure the current running through each pot. Actually when the resistance of the pot is varied via the wiper/swiper, the current and voltage changes too right? Therefore all the changes must be concurrently displayed via our LCD. We are gonna try connecting: pin1 of the pot to ground, pin2 to PORTA aka the ADC input, and pin3 to 5V. I'll let you know the results once we've tried it out, about 2 days later. =)
Hi. We've jumped to the programming part of our project as we've not much time left, and the programming usually takes a lot more time (for us). Any help with the programming would be appreciated. We're using pic18F452 with the picdem 2 plus demo board. Our input would be that from the circuit with the pot mentioned above but right now we're using the pot connected via RA0.
I've managed to display 0V and 5V on the lcd when i turn the wiper of the pot CCW or CW completely. Now I'm trying to detect 1V when I'm adjusting the wiper but there are 2 problems. Firstly, As you can see from my programming, my constant values are 0x01 and 0x05, which I assume should read analog inputs of lower than 1V and higher than 5V. (Am I right?) It works on the program but still would like to double check it. My second problem is designing a subroutine to detect the 1V. How should I go about it?
That code will work in MPLAB as long as you select the C18 compiler. If you don't have the C18 compiler you can download a free version from Microchip.
This website has exactly what your looking for but a different PIC
BUT it measures voltage, current, frequency etc. look at the super probe Mondo Technology - Pic Projects
It has the code, just need to convert for the desired PIC
but in mondo technology, it uses seven segment output. i need to display voltage, current and temperature in 1 lcd16x2. i can figure that out.
but what i need to understand now is; for sensing the voltage and current, which type of ic is needed. im using microcontroller pic 18f4520. can those ic connected to pic18f4520?
If you learn how to program the chip then you will be able to make it do whatever you want. You do not need another chip, the chip you have can do what you want. Try to write some code and then post it here. If it doesn't work we will help you to get it working.