Good day all gurus
Here is what I am trying to achieve. I wish to setup an electronic vacuum pump controller so that I can maintain a constant level of vacuum in a vacuum bagging system.
I have not been able to find any such thing on the internet that is within the range of the DIY'er and thought seeing as I have arduino why not build one.
Now what I need is I have a 220v vacuum pump that is connected to a vacuum reservoir but I need something to turn the pump on when the level of vacuum pressure falls below a set level and turn the pump off when it reaches the desired level of vacuum.
Digikey supply MPXV6115VC6U-ND which is a vacuum sensor and this I would assume can be controlled with a relay and two trimmer pots. I would like to connect an lcd to the system which will display the low and high level pressures settings to control the pump.
I have seen the exact item that would suit me but I does not appear that they ship to the UK. 
or their website is wonkey and will not allow me to pay for it.
So can anyone please help me or point me in the right direction to build one of these. I would be so grateful if you could.
What experience do you have with programming and electronics?
I would start with programming the reading of the sensor with output to the serial terminal. Once you have the basic reading displayed, add a trimpot to an analogue input for use as a reference to compare the vacuum reading. Use this to turn on a relay.
You will need a means of converting the analogue values from the sensor to absolute pressure readings for output to the display.
Then add the LCD.
Weedpharma
Have you seen joewoodworker.com? Sells all the parts and has good tutorials on how to put the things together.
Absolute pressure is the wrong thing to measure. You need a differential pressure sensor. There are a lot of Freescale sensors that are suitable. Look for the ones with the built-in compensation. The through-hole ones that look like little banjos will fit a breadboard or 0.1" prototype board. A quick relay shield and LCD shield on top of the Arduino and then it's just a matter of writing code.
RS has them, farnell and many others sell the sensor,
however even a old pressure sensor from a washing machine will do, as you only need a starterand a stopper, when the vacuum is reached seal the bag and switch off the vacuum.
You still need an "unloader" or "Mac" valve to relieve the pressure on the pump when it shuts off. Without it you put a lot of strain on the pump when it starts up, and/or leaving the pressure on the pump when it is off is just a bad idea.
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To one and all I am humbled by your advice. I thank you. This is where I am. I have acquired the parts I need and as to my electronic experience well lets say I have worked through some of the examples. As far as the code goes I have no idea were to start but I will keep searching this wonderful forum till I have a working model of what I need. I like @Weedpharma 's approach thank you.
@chagrin that is where I got the idea from but I wish to remove as much of the mechanics from his system as possible.
I have all the mechanical bits to make the system work I now also have all the electronic bit I need. So I now will need constructive input as to how to breadboard it all and how to write the code. The vacuum sensors I will be using are SENSOR DIFF PRESS 2.2PSI MAX PN MPXV6115VC6U-ND from digikey.
this will be driven by an arduino uno. So any circuit and code input will be welcome
Many thanks again.
The sensor needs to be connected to 5v, gnd and an analogue input. The data sheet gives a graph of the output against pressure so you can convert the voltage to pressure.
Read sensor
Convert to pressure
Output to serial terminal
Repeat
Once you have this working, add a 10k potentiometer (1 end to 5v, other to gnd, wiper to another analogue input) to set the comparison value.
Set pot to a position
Read pot
Convert to pressure required. (Assume linear pressure change over the range required)
Read sensor
Convert to pressure
Output to terminal
Compare pressure to set value and turn on LED if required.
Repeat
Weedpharma
hi ,
i am doing a project in this semester. i would like to know that how to extract data from vacuum pump A1803H through Ardduino?
