From decb27cbdc6b1886c60cc9f7294db22e34fbd9e3 Mon Sep 17 00:00:00 2001
From: shylie <shylie@shylie.info>
Date: Thu, 5 Jun 2025 01:04:13 -0400
Subject: [PATCH] Use adafruit encoder breakouts for controls instead

---
 pong/src/main.cpp | 43 +++++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/pong/src/main.cpp b/pong/src/main.cpp
index a640c68..0f12e70 100644
--- a/pong/src/main.cpp
+++ b/pong/src/main.cpp
@@ -46,9 +46,24 @@ struct rect
   }
 };
 
-constexpr uint8_t LEFT_BUTTON   = 2;
-constexpr uint8_t MIDDLE_BUTTON = 3;
-constexpr uint8_t RIGHT_BUTTON  = 4;
+int32_t get_encoder_delta(i2c_inst* i2c, uint8_t address)
+{
+  // SEESAW_ENCODER_BASE and SEESAW_ENCODER_DELTA values
+  // https://github.com/adafruit/Adafruit_Seesaw/blob/master/Adafruit_seesaw.h
+  uint8_t buf[4] = { 0x11, 0x40, 0x00, 0x00 };
+  i2c_write_blocking(i2c, address, buf, 2, false);
+  sleep_us(250);
+  i2c_read_blocking(i2c, address, buf, 4, false);
+  return
+    (static_cast<int32_t>(buf[0]) << 24) |
+    (static_cast<int32_t>(buf[1]) << 16) |
+    (static_cast<int32_t>(buf[2]) << 8 ) |
+    (static_cast<int32_t>(buf[3]) << 0 );
+}
+
+constexpr uint8_t LEFT_ENCODER_ADDRESS = 0x36;
+constexpr uint8_t RIGHT_ENCODER_ADDRESS = 0x37;
+constexpr uint8_t OLED_ADDRESS = 0x3C;
 
 constexpr float PADDLE_SPEED = 20;
 constexpr float INITIAL_BALL_SPEED = 32;
@@ -60,23 +75,13 @@ int main()
   stdio_usb_init();
   srand(time_us_64());
 
-  i2c_init(i2c0, 3 * 1000 * 1000);
+  i2c_init(i2c0, 1000 * 1000);
   gpio_set_function(0, GPIO_FUNC_I2C);
   gpio_set_function(1, GPIO_FUNC_I2C);
   gpio_pull_up(0);
   gpio_pull_up(1);
 
-  gpio_set_function(LEFT_BUTTON, GPIO_FUNC_SIO);
-  gpio_set_function(MIDDLE_BUTTON, GPIO_FUNC_SIO);
-  gpio_set_function(RIGHT_BUTTON, GPIO_FUNC_SIO);
-  gpio_set_dir(LEFT_BUTTON, GPIO_IN);
-  gpio_set_dir(MIDDLE_BUTTON, GPIO_IN);
-  gpio_set_dir(RIGHT_BUTTON, GPIO_IN);
-  gpio_pull_down(LEFT_BUTTON);
-  gpio_pull_down(MIDDLE_BUTTON);
-  gpio_pull_down(RIGHT_BUTTON);
-
-  picoled::ssd1306 oled(i2c0, 0x3C);
+  picoled::ssd1306 oled(i2c0, OLED_ADDRESS);
   oled.update();
 
   rect player = { 8.0f, oled.get_height() / 2.0f - 8.0f, 4.0f, 16.0f };
@@ -109,11 +114,13 @@ int main()
     float dt = std::abs(current - us) / 1000000.0f;
     us = current;
 
-    if (gpio_get(LEFT_BUTTON)) { player.y -= PADDLE_SPEED * dt; }
-    if (gpio_get(MIDDLE_BUTTON)) { player.y += PADDLE_SPEED * dt; }
+    int32_t left_enocder_delta = get_encoder_delta(i2c0, LEFT_ENCODER_ADDRESS);
+    int32_t right_encoder_delta = get_encoder_delta(i2c0, RIGHT_ENCODER_ADDRESS);
+
+    player.y += 2 * right_encoder_delta;
 
     float diff = ball.middle_v() - ai.middle_v();
-    ai.y += 1.35f * diff * dt;
+    ai.y += 1.4f * diff * dt;
 
     ball.x += ball_dx * dt * ball_speed;
     ball.y += ball_dy * dt * ball_speed;