Digital Voltmeter and ammeter

I found a project of Digital Voltmeter and ammeter in a website but they don't give the source or hex file. can anyone recommended me a good project as provided in this website? Digital Voltmeter Ammeter

This is the start of it. At the moment it only reads the voltage, I've only ran it in sim but should be close enough to the true reading, Give me a bit more time and I will add the current readings and calibration part

See how you get on and let me know how good it is. The hex code is based on the first design in post one you gave the link for.

I would personally use and op-amp to buffer the input of the voltage and may be one on the current to boost the voltage input across the current resistor or depending on how much current you need to read may be use a shunt you could measure upto 300amps. I will aslo knock up a schematic to go with it.

Update: Version 2 it now reds amps 0-1V input reads 0-10amps

wizpic

Here you go, The drawing is the same, The only thing that may be slighty differtent is that the current input is 0-1V for 0-10A reading and the calibration mode is a bit differnece. But you should be able to take the input voltage for the current upto 4.99V has the meter stores the new readings. Say if you had a current flowing of 5amps and the voltage was 1.39V just press the up/down button's until your readings are matched.
Let me know how you get on. What I have noticed is you get about 40mv difference in the readings if you calibrate at the low end or the higher end which is not to bad considering it is only a 10bit pic. EG. if you set your voltage to 28.43V then calibrated it to read the same 28.43V on the pic meter and then adjusted the voltage say to 3.49V on your multi-meter the pic meter will read 3.53V which is 40MV. So far at the moment I've only ran this in sim. Yet to try it in real time but it should work the same.

Here is the calibration settings:
The Voltmeter Ammeter can be easily calibrated by temporarily connecting three (SETUP, UP & DOWN) tactile buttons or even a piece of wire to C1, C2 and C3 PIC16F876 microcontroller ports. But C1, C2, C3 must be held low with a 4K7 resistor
To enter the calibration setup mode make sure the meter is powered off. Press and hold the SETUP button while powering the meter until "Calibration Mode" message is displayed on LCD display. Release the SETUP button

after "Calibration Mode" message disappears this will show “Calibrate Volts” we will be calibrating the voltage readings and real time voltage reading will be displayed on the display. Connect the highest voltage to Input that you will be normally measuring then connect the commercial multimeter to input as well. We will be matching the voltage of PIC voltmeter with the commercial multimeter. Use UP & DOWN buttons to match the voltage on both devices.
Once the voltage is matched and your happy with it press the SETUP button This will then show “Calibrate Amps” we will be calibrating the current readings and real time current reading will be displayed on the display. Lower the voltage on the PSU Connect a load a load from 500MA to 2A in series with your multi-meter to the output of the Pic multi-meter, Again we will be matching the current readings on both meters. Again once your happy with the readings press SETUP button this will the store the calibrated setting in the Non-volatile EEPROM memory and automatically restart the PIC multi-meter. No need for power down. Calibration process now completed. EEPROM memory is retained even if the power supply is disconnected. The calibration process only needs to be performed once. If you ever need to change the calibration settings again you can do so by just following the calibration process again.

Wizpic

PIC16F688 Digital Voltmeter
PIC-based Digital Voltmeter (DVM) :Embedded Lab

There both the same voltmeter for the links you've pasted but the trouble is it does not so you how accurate it is only against an analogue meter. There is plenty out there but I always like to do my own so you know it works well

I have found an error in software the reading are not stable, It's ok in sim but not real time I shall alter the code and run some tests and see how it gores from there

EDIT: I have sorted out the bug, My set up I read 0-33V and 0-70amps using a 70A 75mv shunt and used an op-amp to boost voltage to 0 - 2.99V = 0 - 70amps, but like I said before you can calibrate this to siut your own needs I used 0.1% resistors. Not fully tested the max volatge but should easy handle 70V +

All readings are now stable and don't bounce up and down. I know it works now becasue I have it set up on my work bench ready to go into my 4 channel SD data logger project

Sorry version 4A is set for an 18F4520 at 8MHZ
This is the correct version and I done a drawing for it, With a op-amp has a gain and buffer part, The rest of the circuit is the same, This is suited to my test board

any questions just ask

I've got some doubt: current shunt is 0.47R 5W resistor and range is supposed to be 10A. quickly calculating power dissipation in the resistor will be I^2*R which in this case is 10*10*0.47=47W. Resistor is rated at 5W. Good luck with that, expect smoke if you want to measure high currents.

poorchava said:

I've got some doubt: current shunt is 0.47R 5W resistor and range is supposed to be 10A. quickly calculating power dissipation in the resistor will be I^2*R which in this case is 10*10*0.47=47W. Resistor is rated at 5W. Good luck with that, expect smoke if you want to measure high currents.

Click to expand...

That's why I use a metal plate shunt 75amp with 75mv output, I did think that .47R 5W is to low, But it's not my design I just wrtoe the software to siut it.

need info about your data logger project
can you add more input for reading voltage and frequency counter?

tanveerriaz said:

need info about your data logger project
can you add more input for reading voltage and frequency counter?

Click to expand...

You can have upto 16 channels of reading voltage/current or any type of sensor, Not sure about frequency counter never really done anything like that but i would suppose it is possible

The meter is good .After the calibration works some time.Next show,sCONTACT WIZPIC EDA FORUM. How to get the original version

Here is the calibration settings:
The Voltmeter Ammeter can be easily calibrated by temporarily connecting three (SETUP, UP & DOWN) tactile buttons or even a piece of wire to C1, C2 and C3 PIC16F876 microcontroller ports. But C1, C2, C3 must be held low with a 4K7 resistor
To enter the calibration setup mode make sure the meter is powered off. Press and hold the SETUP button while powering the meter until "Calibration Mode" message is displayed on LCD display. Release the SETUP button

after "Calibration Mode" message disappears this will show “Calibrate Volts” we will be calibrating the voltage readings and real time voltage reading will be displayed on the display. Connect the highest voltage to Input that you will be normally measuring then connect the commercial multimeter to input as well. We will be matching the voltage of PIC voltmeter with the commercial multimeter. Use UP & DOWN buttons to match the voltage on both devices.
Once the voltage is matched and your happy with it press the SETUP button This will then show “Calibrate Amps” we will be calibrating the current readings and real time current reading will be displayed on the display. Lower the voltage on the PSU Connect a load a load from 500MA to 2A in series with your multi-meter to the output of the Pic multi-meter, Again we will be matching the current readings on both meters. Again once your happy with the readings press SETUP button this will the store the calibrated setting in the Non-volatile EEPROM memory and automatically restart the PIC multi-meter. No need for power down. Calibration process now completed. EEPROM memory is retained even if the power supply is disconnected. The calibration process only needs to be performed once. If you ever need to change the calibration settings again you can do so by just following the calibration process again.

Wizpic

Click to expand...

how to Get the code

jacobcies@gmail.com said:

The meter is good .After the calibration works some time.Next show,sCONTACT WIZPIC EDA FORUM. How to get the original version

Here is the calibration settings:
The Voltmeter Ammeter can be easily calibrated by temporarily connecting three (SETUP, UP & DOWN) tactile buttons or even a piece of wire to C1, C2 and C3 PIC16F876 microcontroller ports. But C1, C2, C3 must be held low with a 4K7 resistor
To enter the calibration setup mode make sure the meter is powered off. Press and hold the SETUP button while powering the meter until "Calibration Mode" message is displayed on LCD display. Release the SETUP button

after "Calibration Mode" message disappears this will show “Calibrate Volts” we will be calibrating the voltage readings and real time voltage reading will be displayed on the display. Connect the highest voltage to Input that you will be normally measuring then connect the commercial multimeter to input as well. We will be matching the voltage of PIC voltmeter with the commercial multimeter. Use UP & DOWN buttons to match the voltage on both devices.
Once the voltage is matched and your happy with it press the SETUP button This will then show “Calibrate Amps” we will be calibrating the current readings and real time current reading will be displayed on the display. Lower the voltage on the PSU Connect a load a load from 500MA to 2A in series with your multi-meter to the output of the Pic multi-meter, Again we will be matching the current readings on both meters. Again once your happy with the readings press SETUP button this will the store the calibrated setting in the Non-volatile EEPROM memory and automatically restart the PIC multi-meter. No need for power down. Calibration process now completed. EEPROM memory is retained even if the power supply is disconnected. The calibration process only needs to be performed once. If you ever need to change the calibration settings again you can do so by just following the calibration process again.

Wizpic

Click to expand...

This is over 2 years old and your the first person to ask this, I put a time limit in to actually see how many people would build it and use it well spotted
What voltage and current range you need and I will see if I've still got the original code and take out the time limit

wizpic

wizpic said:

This is over 2 years old and your the first person to ask this, I put a time limit in to actually see how many people would build it and use it well spotted
What voltage and current range you need and I will see if I've still got the original code and take out the time limit

wizpic

Click to expand...

We are tried many time same with your calibration procedure. after the calibration works normally only 3 minuts,.....lcd show's CONTACT WIZPIC EDA FORUM, This is our last attempt.

could you mind to share the code ?

wizpic said:

This is over 2 years old and your the first person to ask this, I put a time limit in to actually see how many people would build it and use it well spotted
What voltage and current range you need and I will see if I've still got the original code and take out the time limit

wizpic

Click to expand...

could you mind to share the code ?