Week 2: Embedded Programming
Assignment Details
group assignment:
• demonstrate and compare the toolchains and development workflows
for available embedded architectures
individual assignment:
• browse through the data sheet for a microcontroller
• write and test a program for an embedded system using a microcontroller
to interact (with input &/or output devices)
and communicate (with wired or wireless connections)
• extra credit: assemble the system
• extra credit: try different languages &/or development environmentsFor the first part of the assignment, I decided to look through the datasheet for the RP2040, because that is the chip that we are using this week.
I learned a lot from reading through it! I had never looked at the datasheet for anything more complex than a 555 timer, so the information in this one was initially a little overwhelming. It was broken down really well though, so I felt like I could understand some of what I was looking at.
Then, I followed Quentin’s guide (link here!) to assemble the QPAD. I have soldered before, so the soldering went quickly and without any issues. Here’s some pictures of the assembled board:
To test the board, I played around with all of the example programs in the guide. Each one worked, which was exciting! I appreciated being able to test with code that I knew would work so I could rule out hardware and software issues separately.
Because the board came with six buttons, I wanted to program a game for it. I spent a lot of time (too much time) trying to decide what kind of game to make. Finally, I landed on making a flappy bird game (which actually only requires one button oops).
To program the QPad, I decided to use Thonny and micropython. I chose this because I spent a good bit of time using the Arduino IDE this summer at my internship, and wanted to learn about something different.
I followed these instructions to get MicroPython setup on the Xiao. Then, I got to work programming! I started out by really reading the example code in-depth, to try to understand what we’re doing. Then, I worked up from the simplest parts of the game.
First, making a bird show up:
Then, making it fall and jump:
.gif)
Adding obstacles:
And a score counter:
And finally, the game worked!
Then, I wanted to add some additional features. First, I added reset button, and variable width obstacles. At first when I was trying to decide what kind of game to make, I was considering recreating space invaders. So, I thought it would be fun to add some sort of shooting aspect to the game. I decided to make it so that the obstacles would disappear if the bird shot them a couple of times. I ended up asking ChatGPT to make the modifications, and then read through them.
Here is my code:
My Code
# Flappy Bird game by Sophia Woodbury
import random
####### copied from example hello_qed ########
from steptime import STEPTIME
from ssd1306 import SSD1306_I2C
from machine import Pin, I2C, freq
import utime
# Your steptime demo uses high clock
freq(250000000)
# OLED (same as your hello_oled.py)
i2c = I2C(1, scl=Pin(7), sda=Pin(6), freq=200000)
oled = SSD1306_I2C(128, 64, i2c)
# Touch pads (same as your hello_touch_neopixel.py)
PAD_PINS = [26, 27, 1, 2, 3, 4] # pads 1..6
for p in PAD_PINS:
Pin(p, Pin.IN, Pin.PULL_UP)
# Channels: one STEPTIME per pad (sm_id 0..5)
channels = []
for i, pin in enumerate(PAD_PINS):
channels.append([STEPTIME(i, pin), [1e6], [0]]) # [sm, [min], [delta]]
# Steptime tuning (from your demo)
LOOP = 200
SETTLE = 20000
THRESH = 10000 # adjust if needed
# Debounce / tap detection
DEBOUNCE_MS = 180
tap_armed = [True] * 6
last_edge_ms = [0] * 6
def read_touch_deltas():
deltas = [0] * 6
for i, ch in enumerate(channels):
sm, min_val, printable = ch
sm.put(LOOP)
sm.put(SETTLE)
raw = 4294967296 - sm.get() # same as your demo
if raw < min_val[0]:
min_val[0] = raw
d = raw - min_val[0]
printable[0] = d
deltas[i] = d
return deltas
def pad_pressed(deltas, i):
return deltas[i] > THRESH
########## end copied from example #########
# game setup
game_over = False
score = 0
# bird setup
bird_x = 30
bird_y = 30
velocity_y = 0
jump_amt = -3
# obstacle setup
hit_x = 120
gap_y = 25
hit_width = 15
gap_height = 20
hit_speed = 2
def check_collisions():
bird_r = bird_x + 6
bird_b = bird_y + 6
hit_r = hit_x + hit_width
horiz_hit = ((bird_r > hit_x) and (bird_x < hit_r))
vert_hit = ((bird_y < gap_y) or bird_b > gap_y + gap_height)
return (horiz_hit and vert_hit)
was_pressed = False
while True:
# clear the screen
oled.fill(0)
# move the bird
velocity_y = velocity_y + 0.5
bird_y = bird_y + velocity_y
# constrain bird movement
if bird_y < 0:
bird_y = 0
game_over = True
if bird_y >= 60:
bird_y = 60
game_over = True
# button stuff
deltas = read_touch_deltas()
pressed = [pad_pressed(deltas, i) for i in range(6)]
# make bird jump
is_pressed = any(pressed)
if is_pressed and not was_pressed: # only on new taps (no hold)
velocity_y = jump_amt
was_pressed = is_pressed
# move obstacles
hit_x = hit_x - hit_speed
if hit_x < -hit_width: # reset when on left side of screen
hit_x = 128
gap_y = random.randint(15, 30)
score += 1
hit_speed = 2 + (score // 10) # increase speed (difficulty)
# collision
if check_collisions():
game_over = True
# game over
if game_over:
oled.text("GAME OVER :(", 25, 20)
oled.text(f"Score: {score}", 25, 32)
oled.text("press to reset", 25, 44)
oled.show()
# look for button press
deltas = read_touch_deltas()
pressed = [pad_pressed(deltas, i) for i in range(6)]
# reset the game if pressed
if any(pressed):
game_over = False
bird_y = 30
velocity_y = 0
hit_x = 100
gap_y = 25
score = 0
hit_speed = 2
utime.sleep_ms(50)
continue
# draw the bird
oled.rect(bird_x, int(bird_y), 6, 6, 1)
# draw obstacles (hit)
oled.fill_rect(hit_x, 0, hit_width, gap_y, 1) # top rect
bottom_hit_y = gap_y + gap_height
oled.fill_rect(hit_x, bottom_hit_y, hit_width, 64 - bottom_hit_y, 1)
oled.text(f"Score: {score}", 0, 0)
# show the new screen
oled.show()
# wait a lil
utime.sleep_ms(50)
ChatGPT-modified code
import random
####### copied from example hello_qed ########
from steptime import STEPTIME
from ssd1306 import SSD1306_I2C
from machine import Pin, I2C, freq
import utime
# Your steptime demo uses high clock
freq(250000000)
# OLED (same as your hello_oled.py)
i2c = I2C(1, scl=Pin(7), sda=Pin(6), freq=200000)
oled = SSD1306_I2C(128, 64, i2c)
# Touch pads (same as your hello_touch_neopixel.py)
PAD_PINS = [26, 27, 1, 2, 3, 4] # pads 1..6
for p in PAD_PINS:
Pin(p, Pin.IN, Pin.PULL_UP)
# Channels: one STEPTIME per pad (sm_id 0..5)
channels = []
for i, pin in enumerate(PAD_PINS):
channels.append([STEPTIME(i, pin), [1e6], [0]])
# Steptime tuning
LOOP = 200
SETTLE = 20000
THRESH = 10000
# Debounce / tap detection
DEBOUNCE_MS = 180
tap_armed = [True] * 6
last_edge_ms = [0] * 6
def read_touch_deltas():
deltas = [0] * 6
for i, ch in enumerate(channels):
sm, min_val, printable = ch
sm.put(LOOP)
sm.put(SETTLE)
raw = 4294967296 - sm.get()
if raw < min_val[0]:
min_val[0] = raw
d = raw - min_val[0]
printable[0] = d
deltas[i] = d
return deltas
def pad_pressed(deltas, i):
return deltas[i] > THRESH
########## end copied from example #########
# ==================================================
# GAME SETUP
# ==================================================
game_over = False
score = 0
# ==================================================
# BIRD SETUP
# ==================================================
bird_x = 30
bird_y = 30
velocity_y = 0
jump_amt = -3
# ==================================================
# OBSTACLE SETUP
# ==================================================
hit_x = 120
gap_y = 25
hit_width = 15
gap_height = 20
hit_speed = 2
# Number of times the pipe has been hit
pipe_hits = 0
# Number of hits needed to destroy the pipe
hits_needed = 3
# ==================================================
# PROJECTILE SETUP
# ==================================================
bullet_active = False
bullet_x = 0
bullet_y = 0
# Projectile speed
bullet_speed = 7
bullet_width = 3
bullet_height = 2
# ==================================================
# COLLISION FUNCTIONS
# ==================================================
def check_collisions():
bird_r = bird_x + 6
bird_b = bird_y + 6
hit_r = hit_x + hit_width
horiz_hit = ((bird_r > hit_x) and
(bird_x < hit_r))
vert_hit = ((bird_y < gap_y) or
(bird_b > gap_y + gap_height))
return (horiz_hit and vert_hit)
# Check whether projectile hits the pipe
def check_bullet_collision():
bullet_r = bullet_x + bullet_width
bullet_b = bullet_y + bullet_height
hit_r = hit_x + hit_width
# Check horizontal overlap
horiz_hit = ((bullet_r > hit_x) and
(bullet_x < hit_r))
if not horiz_hit:
return False
# Check whether bullet is in the
# top or bottom part of the pipe
top_hit = bullet_y < gap_y
bottom_hit = bullet_b > gap_y + gap_height
return top_hit or bottom_hit
# ==================================================
# BUTTON STATE
# ==================================================
# Used to detect a new jump tap
was_pressed = False
# Used to detect a new shooting tap
shoot_was_pressed = False
# ==================================================
# MAIN GAME LOOP
# ==================================================
while True:
# ------------------------------------------------
# CLEAR SCREEN
# ------------------------------------------------
oled.fill(0)
# ------------------------------------------------
# MOVE THE BIRD
# ------------------------------------------------
velocity_y = velocity_y + 0.5
bird_y = bird_y + velocity_y
# Keep bird on screen
if bird_y < 0:
bird_y = 0
game_over = True
if bird_y >= 60:
bird_y = 60
game_over = True
# ------------------------------------------------
# READ BUTTONS
# ------------------------------------------------
deltas = read_touch_deltas()
pressed = [
pad_pressed(deltas, i)
for i in range(6)
]
# ------------------------------------------------
# JUMP
# ------------------------------------------------
# Pad 1 = jump
jump_pressed = pressed[0]
if jump_pressed and not was_pressed:
velocity_y = jump_amt
was_pressed = jump_pressed
# ------------------------------------------------
# SHOOTING
# ------------------------------------------------
# Pad 2 = shoot
shoot_pressed = pressed[1]
if shoot_pressed and not shoot_was_pressed:
# Only shoot if there is not already
# a projectile on the screen
if not bullet_active:
bullet_active = True
# Start projectile at the front
# of the bird
bullet_x = bird_x + 6
# Start projectile at the bird's
# current vertical position
bullet_y = int(bird_y) + 2
shoot_was_pressed = shoot_pressed
# ------------------------------------------------
# MOVE PROJECTILE
# ------------------------------------------------
if bullet_active:
bullet_x = bullet_x + bullet_speed
# Check whether projectile hit pipe
if check_bullet_collision():
# Remove projectile
bullet_active = False
# Add one hit to the pipe
pipe_hits = pipe_hits + 1
# Destroy pipe after enough hits
if pipe_hits >= hits_needed:
# Move pipe off screen
hit_x = -hit_width
# Give player a point
score = score + 1
# Remove projectile if it
# leaves the screen
elif bullet_x > 128:
bullet_active = False
# ------------------------------------------------
# MOVE OBSTACLE
# ------------------------------------------------
hit_x = hit_x - hit_speed
# If pipe leaves screen,
# create a new one
if hit_x < -hit_width:
hit_x = 128
gap_y = random.randint(15, 30)
# Reset pipe health
pipe_hits = 0
# Player successfully passed
# the pipe
score = score + 1
# Increase speed every 10 points
hit_speed = 2 + (score // 10)
# ------------------------------------------------
# COLLISION
# ------------------------------------------------
if check_collisions():
# Only check collision if pipe
# is actually on screen
if hit_x >= 0:
game_over = True
# ------------------------------------------------
# GAME OVER
# ------------------------------------------------
if game_over:
oled.text("GAME OVER :(", 15, 20)
oled.text(
f"Score: {score}",
15,
32
)
oled.text(
"press to reset",
10,
44
)
oled.show()
# Check for button press
deltas = read_touch_deltas()
pressed = [
pad_pressed(deltas, i)
for i in range(6)
]
# Reset game if a button is pressed
if any(pressed):
game_over = False
bird_y = 30
velocity_y = 0
hit_x = 120
gap_y = 25
score = 0
hit_speed = 2
# Reset pipe health
pipe_hits = 0
# Reset projectile
bullet_active = False
bullet_x = 0
bullet_y = 0
utime.sleep_ms(50)
continue
# ------------------------------------------------
# DRAW BIRD
# ------------------------------------------------
oled.rect(
bird_x,
int(bird_y),
6,
6,
1
)
# ------------------------------------------------
# DRAW OBSTACLES
# ------------------------------------------------
# Only draw pipe if it is on screen
if hit_x >= 0:
# Top pipe
oled.fill_rect(
hit_x,
0,
hit_width,
gap_y,
1
)
# Bottom pipe
bottom_hit_y = gap_y + gap_height
oled.fill_rect(
hit_x,
bottom_hit_y,
hit_width,
64 - bottom_hit_y,
1
)
# Show pipe health
oled.text(
f"{pipe_hits}/{hits_needed}",
hit_x,
gap_y + 7
)
# ------------------------------------------------
# DRAW PROJECTILE
# ------------------------------------------------
if bullet_active:
oled.fill_rect(
int(bullet_x),
int(bullet_y),
bullet_width,
bullet_height,
1
)
# ------------------------------------------------
# DRAW SCORE
# ------------------------------------------------
oled.text(
f"Score: {score}",
0,
0
)
# ------------------------------------------------
# SHOW SCREEN
# ------------------------------------------------
oled.show()
# Wait a little
utime.sleep_ms(50)
Link to my conversation with ChatGPT: https://chatgpt.com/share/6acd534c-d1cc-83ea-b76a-db108dd70923