SBC Projects: STEM Education in NYC

In our SBC Project series, we feature unique and interesting single-board computer (SBC) projects from the maker community. If you’d like to share your Raspberry Pi, BeagleBone Black, or other SBC project with thousands of other makers, complete our short form and we’ll get in touch!

In this post, we’ll meet Charlie Galliher from the New York City area.

What are you working on, Charlie?

I am developing STEM in elementary education.

As an example, in one my lessons, I teach kids how to code for a circuit using a light resistor and capacitor on a RPi.

This was the last of a ten-lesson set about the Raspberry Pi, and the demonstration began by introducing an OSCOPE reading the frequency of capacitor discharge using a photo sensitive light resistor (Adafruit has this on-line). Kids can see the length of the wave increase as resistance increased when we darkened the room.


We went over the code, discussed the functions that brought the frequency into the code and how to manipulate it to different outputs, including a powertail running a string of bright leds.

Below is some code I got and adapted from either Adafruit or a link from some Pi-related source like Simon Monk. – I do not remember, but I take no credit for the code – just for implementing it, with my partner Deb Lasala, to classes of ten students each.

The coding part starts with a single LED that turns on and off based on a set value returned from the light sensor capacitor. Students will then be expected to identify a working gpio pin on the pi and code to light a second and then a third LED based on bright, less bright, and dark conditions.

unnamed (1)

The students are asked to add LEDs and to modify the below code. The below code sample is complete. Students are given the code with a single LED and are asked to add them. They also have been given the GPIO mappings for coding.

# Example for RC timing reading for Raspberry Pi
# Must be used with GPIO 0.3.1a or later – earlier verions
# are not fast enough!

import RPi.GPIO as GPIO, time, os

# ====================================================
def RCtime (RCpin):
reading = 0
GPIO.setup(RCpin, GPIO.OUT)
GPIO.output(RCpin, GPIO.LOW)

def blink(pin):

def blinkoff(pin):

        GPIO.setup(RCpin, GPIO.IN)
# This takes about 1 millisecond per loop cycle
while (GPIO.input(RCpin) == GPIO.LOW):
reading += 1
return reading

while True:
if inpVal <= 120:
print “it’s bright, no light for you!=”
print inpVal
#                                    =============
elif inpVal >= 121 and inpVal <= 160:
print “It’s kind of light – one light for you”
print inpVal
#                                    =============
elif inpVal >= 122 and inpVal <= 200:
print “It’s getting darker – two lights for you”
print inpVal
#                                    =============
print “It’s dark. Let me turn on a light so you don’t strain your eyes. =”
print inpVal
#                                    =============

What’s tough about STEM education?

I have an AE in industrial electronics and computers, an MEd in education and a BFA in Fine Arts… I get the code and the direction that the Maker movement is heading and see this as an open door into developing STEM in education.

The big issue we face in education is to integrate the technology and to make it successful – and it changes so fast that it’s hard to do. The good news is that electronics is electronics and that will not change, that Linux is Linux and it seems to me that it will be the platform for the IOT for the foreseeable future, and both are ridiculously cheap – the same can be said for the hardware it’s on (arduinos, RPi’s, beaglebones, etc…)

Our issue is and will continue to be providing the teachers with an educational design that will work for them, and this is going to take time.

Charlie wanted to make sure we gave credit to both Deb Lasala, his co-teacher, as well as Ridgefield Academy.. If it were not for the support he gets, he would not be developing STEM to the extent he has been able to.


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