Good afternoon, 12 year old science project due 16th, spent weekend trying to hook this up. We are able to get power to the AD8232 but can’t get the LED lights to light up. He is making the wearable style with a light that blinks with his heartbeat. We ordered the pulse sensor and pads and LED light strip parts. On the board we assume the gnd and 3.3v are for power, the output is for downloading to a computer and the lo- / lo+ would go to the led light? Meter doesn’t indicate a signal emanating from these lo- / lo+ leads… I uploaded an image from science buddies of a similar style. We have the AD8232 unit in a small box w battery and jack opening on the side. We plan to mount the LED light on the top of the box. We also used the meter and don’t get continuity on the led light itself attaching on the - / + light terminals. We also assume there would be a signal on the lo- / lo+ leads on the AD8232 board as the heart beat signal is relayed and don’t have a signal there either.
Looking at the data sheet, LO+ and LO- are signals that indicate if one of the two sensor pads have fallen off. It looks like the output is an analog voltage; in the picture you posted, they are probably using the lilypad to read this analog output and drive the LEDs appropriately. Try connecting the meter between pins 1 and 3 of JP3. You may be able to use pin 3 to drive a transistor to control the LED strip (assuming it is not a programmable LED strip).
On the AD8232 output terminal the meter reads a constant voltage of 3.3. We put the LED in circuit from the output onJP3 back to the Lilypad coin battery negative terminal. The light illuminates on the AD8232 and the LED lights up but it remains constantly on. There’s no interruption in the light indicating a heart beat from the pulse sensor. Are we missing something? Does the output voltage signal interrupt in conjunction with the pulse sensor? Do we need a different Arduino other than the single lead AD8232? The pictured one from science buddies is different from the AD8232, we looked on the Sparkfun website under, “Choosing a LilyPad Arduino for Your Project” but don’t know if we need one of these in lieu and if so which one? Additionally don’t see one with a single lead jack… I believe we’re close but need the pulse sensor to impact the LED light accordingly.
We currently have the:
AD8232 single lead heart rate monitor board
single lead pulse sensor and pads
Lilypad coin cell battery holder (switched) and 3.3v battery
Lilypad LED 5 strip
I have some electrical knowledge but am currently at a loss with what we have, your assistance is greatly appreciated.
You can’t connect LEDs directly to the AD8232 I’m afraid. You need to connect the AD8232 to a micro controller and then the micro controller along with a bit of software you write can drive your LEDs.
Have you seen our [hookup guide for this part? That would be a good place to start.
