Summary of Minimal ECG using an Arduino and Xoscillo
This article describes a minimal ECG project using an Arduino and XOSCILLO, an open-source oscilloscope tool. The circuit employs an AD8221 instrumentation amplifier for high CMRR, followed by an op-amp for additional gain. A single 5V supply from the Arduino powers the amplifiers, with a buffered virtual ground essential for operation.
Parts used in the Minimal ECG Project:
- XOSCILLO
- Arduino
- AD8221 Instrumentation Amplifier
- Op Amp
- Instrumental Amplifier (ins amp)
- Breakout Board
- Single Supply (5V from Arduino)
- Buffered Virtual Ground
To display the wave I am using XOSCILLO, a very cool and open source tool (which I wrote :P) that converts your Arduino into an oscilloscope.
Circuit diagram
Here is the scheme, I am using the typical instrumental amplifier(ins amp) and then another op amp to get some more gain. An ins-amp is like an op-amps but with a huge CMRR, I am using a AD8221 which comes in a tiny small package, it’s lead pitch is only 0.65mm, if you want to know what I did to create a simple breakout board please follow this link.
I’m using a single supply for the amps that comes from the arduino 5V pin, and I am creating a buffered virtual ground, this is really important.
For more detail: Minimal ECG using an Arduino and Xoscillo
- What tool is used to display the wave?
XOSCILLO, an open-source tool that converts the Arduino into an oscilloscope. - Which instrumentation amplifier is used in the circuit?
The AD8221 is used because it has a huge CMRR and comes in a tiny package. - How many stages of amplification are implemented?
The circuit uses an instrumental amplifier followed by another op amp to get more gain. - Where does the power supply come from?
A single supply for the amps comes from the Arduino 5V pin. - Why is a buffered virtual ground important?
Creating a buffered virtual ground is described as really important for this setup. - Can I build a breakout board for the AD8221?
Yes, you can create a simple breakout board for the AD8221 which has a lead pitch of only 0.65mm. - Is XOSCILLO proprietary software?
No, XOSCILLO is a very cool and open source tool written by the author.
