Hi all,
I am looking for a product that will be able to convert continuous analog signal (ECG signal) to digital before transmitting it wirelessly to a computer.
May i know which product is the most suitable for such application?
Analog signal is of voltage range from 10mV to 2V. Do let me know if i need to provide you guys with more information.
Thank you!
Hi,
Check out this excellent Australian electronics magazine, (the only Australian electronics magazine).
Also keep an eye on this magazine as they cross pollinate projects.
http://www.epemag.com/index.html
They have just what you are looking for, even a PCB.
Tom...... 
derekyeo:
I am looking for a product that will be able to convert continuous analog signal (ECG signal) to digital before transmitting it wirelessly to a computer.
Isn't that just a simple analog to digital process that could, in theory, be effected with the Arduino's analogRead() function.
I say "in theory" because I don't know what sampling rate would be necessary and the Arduino cannot do very high sampling rates.
You can get ADC conversion chips with very high sampling rates (I have one that can do 40 million SPS) but then you would need more memory to store the data and more bandwith to transmit it.
...R
Robin2:
Isn't that just a simple analog to digital process that could, in theory, be effected with the Arduino's analogRead() function.I say "in theory" because I don't know what sampling rate would be necessary and the Arduino cannot do very high sampling rates.
You can get ADC conversion chips with very high sampling rates (I have one that can do 40 million SPS) but then you would need more memory to store the data and more bandwith to transmit it.
...R
Hi Robin2,
Does this mean that effectively, I can rig up my analog signal to Arduino WiFi Shield 101 analog input and do some programming to transmit the analog input via wifi?
The sampling rate required is at most 500hz. Will it be able to support?
Thanks for helping!
ECG is the dub-dub of a heart beat, yes? So like 120-150 Hz max rate?
Sampling with Arduino 10-bit ADC at 10KHz rate and sending out via Serial.write() at 115200 should be plenty fast.
May need to offset it some to keep it all positive voltage for the ADC:
http://www.cardiofiles.net/my-ecg-nmbers-are-as-follows-can-you-tell-me-what-they-mean-...-592336.html
Keep it to 0 to 1.1V Max and use the internal bandgap reference so that full 10-bit range of the ADC is utilized.
You could off-load the sensor reading part (and gain more resolution...4x the resolution) using a 12bit ADC:
http://www.analog.com/media/en/technical-documentation/data-sheets/AD7992.pdf
This is an I2C device, easily rigged up to an arduino/attiny85/atmegawhatever.
The next question is...where is this data going?
WiFi is awesome yes...it can do like lots of Mbs.
You want 500 x 2byte samples every second. That is 1kB ish a second of raw data.
Bluetooth is 2.4GHz and easily supports this I believe? 1kB = 8,000 bits a second.
Serial data is easily sent via arduino and the HC-05 modules can easily go more than 9600 baud (9,600 bits a second).
The Master:
ATMEGA chip...even an attiny 85 may be able to support this...but use an UNO if you are new to all this.
A 12bit ADC. Your signal is from 10mV to 2V...an amplifier (2.5x) would may be useful to increase the resolution...But more simple, the ADC I linked is 3.3V compatible, so you will still get a decent range using the 3v3 ref pin to power it from the arduino.
You get 4096 distinct vaules between 0 and 3.3V. You are using 2V max...so about 2,500 different values possible between the 10mv and 2V.
An HC-05 module in baud 9600 acting as a master and auto pairs with the slaves HC-05.
The Slave:
Some aruduino...nano/whatever.
HC-05 module in slave mode that auto connects to the master.
Set to baud 9600.
Serial.print any incoming data.
Have putty running on laptop to capture data via "COM" port.
Or do the above...seems a little simpler than my solution :P.
Johnny010:
You could off-load the sensor reading part (and gain more resolution...4x the resolution) using a 12bit ADC:http://www.analog.com/media/en/technical-documentation/data-sheets/AD7992.pdf
This is an I2C device, easily rigged up to an arduino/attiny85/atmegawhatever.
The next question is...where is this data going?
WiFi is awesome yes...it can do like lots of Mbs.You want 500 x 2byte samples every second. That is 1kB ish a second of raw data.
Bluetooth is 2.4GHz and easily supports this I believe? 1kB = 8,000 bits a second.Serial data is easily sent via arduino and the HC-05 modules can easily go more than 9600 baud (9,600 bits a second).
The Master:
ATMEGA chip...even an attiny 85 may be able to support this...but use an UNO if you are new to all this.
A 12bit ADC. Your signal is from 10mV to 2V...an amplifier (2.5x) would may be useful to increase the resolution...But more simple, the ADC I linked is 3.3V compatible, so you will still get a decent range using the 3v3 ref pin to power it from the arduino.
You get 4096 distinct vaules between 0 and 3.3V. You are using 2V max...so about 2,500 different values possible between the 10mv and 2V.
An HC-05 module in baud 9600 acting as a master and auto pairs with the slaves HC-05.
The Slave:Some aruduino...nano/whatever.
HC-05 module in slave mode that auto connects to the master.
Set to baud 9600.
Serial.print any incoming data.
Have putty running on laptop to capture data via "COM" port.
Hi,
One of my project requirement is to transmit the data via wireless means to a computer for digital signal processing. Therefore, i have chosen to use Arduino WiFi Shield 101 for my project. Will there be any complication?
Thanks all for the help!