A story: I remember the first day of 8th grade science. The teacher handed each student a ditto quiz with a ton of questions/tasks. Single-spaced. Two sheets of paper. Maybe there were 50 questions. Maybe 100. There was nothing challenging about any of the questions or challenges. However, the teacher said with great emphasis, “Make sure you read the directions before you start.” Somewhere in the directions was a sentence about reading each question before starting the quiz. I ignored that. Reading through 50-100 questions eats up a lot of time. Why not jump right in?
The last question/task on the quiz went something like this, “Don’t answer any of the questions you just read.”
It was an awful trick that I still resent to this day–many, many years later.
I rarely read directions before jumping right in. If I did, I would’ve rethought my plans for the “Heart on Your Sleeve” Popular Science project back that I found back in February. I ordered the necessary stuff from SparkFun and finally got around to working on it last weekend.
Bits and bobs from the “Heart on Your Sleeve” kit. With some additional things.
For about a year I’ve been sitting (not literally) on a pair of sweatbands that I figured I would embellish with sewable LEDs and LilyTinies. Like most projects, I didn’t finish it. However, the heartbeat project seemed like a good opportunity to use the sweatbands to monitor my pulse while exercising. For fun!
But look at this from the tutorial:
To contract the heart muscle and pump blood, waves of electricity spread through the organ. Two electrodes on the chest, one on either side of the heart, can pick up these electrical impulses. (A third—often placed on the right leg—increases accuracy.)
Having electrodes strapped to my chest and leg will make exercising difficult.
But no worries. Surely sewing them into a wristband so that they pick up the pulse from one’s wrist will work. Right?
I ripped the seam out of the sweatband and sewed on the LEDs.
I then sewed the heart rate monitor into the wristband. I sewed it in upside down thought I can’t remember my reasoning for doing so.
SparkFun’s Heart rate monitor
There was also the questions of sewing the battery pack in without shorting things out. I figured sewing it on to a piece of flannel and then sewing it into the sweatband would work, though I haven’t tested that out yet (and probably won’t. Explanation follows).
Before committing more time to sewing, I wanted to see how things actually worked. I used alligator clips to temporarily connect the positive and negative to power and ground.
We have lights!
Look! Lights! Seeing LEDs light up never gets old. I then connected the sensor pads to my wrist. It monitored my pulse, but…..
… when moving, the LEDs don’t resemble anything like a beating heart.
So…. I’m thinking I’ll disassemble the project and use the heartbeat monitor for something else.
I’ve been reading The Secret History of Wonder Woman, which discusses William Moulton Marston’s work with the lie detector test. Perhaps I’ll create my own lie detector test (or Lasso of Truth) for fun.