hello
in my previous post i asked the forum help on what pressure sensor should i choose, that can detect a pulse in a blood pressure cuff.
I decided to go with the mpxv5050gp, because i didnt want to build an external amplifier circuit .
So i got the sensor and i need some help on how to connect it to the arduino, and also with the code.
I didnt find anything on google, so any help will be welcome!
I just need the sensor to tell me if there is a pulse on a inflated BP cuff.
Thanx
No experience with this, but I can imagine you need two values.
The blood pressure and the tiny heartbeat.
Getting the blood pressure is easy.
Just connect the pressure sensor to an analogue input, and read the digital value.
That value can be converted to blood pressure.
I guess the heartbeat will need amplfication.
After putting "blood pressure" in the search box on top of this page, I saw several old posts about the subject.
Here's one: Blood pressure measurement code - Programming Questions - Arduino Forum
Contains a circuit diagram in the last post.
The analogue heartbeat amplifier part might be usefull.
Note that there are two lines to the micro.
Pressure and heartbeat.
Leo..
I don't need to calculate the BP or even the HB, i just want to know if there is a pulse or not.
When you inflate the BP cuff to a pressure higher then 120-130 mmHg, you prevent the blood from going to the limb, and no blood = no pulse. if you have any sample code, or even something similar (just to get me started), i will appreciate it a lot!!
And about the circuit- i thought that if i choose this sensor, it a matter of just connecting this sensor to the arduino and that's it, because it contain an internal amplifier circuit.
Do i need to build this circuit if i just want to detect a pulse?
Also i added the datasheet of the sensor (i have the one on page 13) - if i want to connect it straight to the arduino - what are the connections?
MPX5050.pdf (387 KB)
david_isr:
...i thought that if i choose this sensor, it a matter of just connecting this sensor to the arduino and that's it, because it contain an internal amplifier circuit.
Do i need to build this circuit if i just want to detect a pulse?
The internal amplifier outputs pressure as a voltage. 0-0.5bar as ~0.5-4.5volt.
Blood pressure can be read directly.
Heartbeat is just a tiny variation in pressure.
I doubt that you can detect that without a pulse amplifier.
Start by connecting the sensor (plus supporting decoupling caps), and try to read pressure only.
The IDE has an AnalogReadSerial example.
Then convert it in your code to mmHg.
If it works, and you understand it, move onto heartbeat.
Leo..
Wawa:
Start by connecting the sensor (plus supporting decoupling caps), and try to read pressure only.
can someone provide a more detailed way of how to connect the sensor to the arduino?
The datasheet is not clear about connecting the sensor package you have.
After some more Googling I found this.
This diagram and the one in a previous link show the same pinouts.
2=+5volt, 3=ground, 4=out.
Note the decoupling caps.
Leo..
Leo thank you for your help!
I came across this project and it uses the Honeywell ASDX 015PDAA5 pressure sensor, that is also have a internal amplifier circuit.
do you think i can use the circuit diagram that they used? (they didn't use any decoupling capacitors)
Seems to be the same sensor with a different pinout.
You could try your sensor without the caps. It might work.
Caps are used for stability, noise removal, etc.
Best to use them in your final circuit.
Dangerous to mention "Instructables" on this forum.
Leo..
Wawa:
Dangerous to mention "Instructables" on this forum.
Leo..
lol ok i will give it a shot... my knowledge in electronics is limited so i prefer to start with the simpler circuit board
Thx for the help!
