Files
ps4-lego-bridge/receiver/receiver.ino
T
jessikitty 39bc43a878 Working configuration - verified on hardware
- Swap HUB0/HUB1 addresses; they were the wrong way round.
- Add DIR_* constants for all seven motors, with DIR_RIGHT_TRACK at -1.
- Swap the right arm buttons: Cross raises, Triangle lowers.
- Move struct Frame into the types block - the Arduino prototype
  generator needs it declared above the first function definition.
- Pin core 2.0.17 in the header; 3.x will not build Legoino.
2026-09-10 11:39:37 +10:00

337 lines
12 KiB
Arduino

/*
* receiver.ino -- UART -> two LEGO Powered Up hubs (ESP32 "B")
*
* Model: Johnny 5 (Short Circuit) MOC, 7 motors across 2 Technic hubs.
*
* Board package: esp32 (the normal Espressif one), core 2.0.17
* Libraries: Legoino + NimBLE-Arduino 1.4.x (both via Library Manager)
*
* Core 3.x will not build Legoino - you get 'std::string does not name a type'
* and a ReadUInt32LE declaration mismatch. Stay on 2.0.17 for this board.
*
* Listens for gamepad frames from the Bluepad32 board on Serial2 and drives
* both hubs over BLE using Legoino. This board must NOT have the Bluepad32
* board package selected - keeping BTstack and NimBLE on separate chips is
* the entire reason there are two boards.
*
* Wiring to the transmitter board:
* RX GPIO16 <- TX GPIO17 on transmitter
* TX GPIO17 -> RX GPIO16 on transmitter
* GND -> GND (mandatory - common ground)
*
* Control scheme is tank drive: every input drives exactly one motor.
*
* FILE ORDER MATTERS:
* The Arduino IDE injects generated function prototypes immediately before
* the FIRST function definition in the file. Any type used in a function
* signature must be declared above that point - which is why HubLink,
* PortState and Frame all live in the types block. Move a function above
* them and you get "'Frame' has not been declared".
*
* Created by: Jess Rogerson (yelling commands at Claude.AI)
*/
#include "Lpf2Hub.h"
// ---------------------------------------------------------------- settings
// Hub BLE addresses. Run tools/hub_scanner to find them - do not guess.
//
// hub 0 - lower body hub 1 - upper body
// A right track A head tilt
// B left track B head turn
// D body lift C left arm
// D right arm
static const char *HUB0_ADDR = "90:84:2b:61:f2:d7";
static const char *HUB1_ADDR = "90:84:2b:61:e6:8c";
// Port numbers are just bytes in the LEGO protocol, same on every hub type.
static const byte PORT_A = 0x00;
static const byte PORT_B = 0x01;
static const byte PORT_C = 0x02;
static const byte PORT_D = 0x03;
// Technic / Control+ motors are tacho motors -> leave this at 1.
// Plain train motors and the simple Powered Up motors -> set it to 0.
#define USE_TACHO_MOTORS 1
// Set to 1 to log every motor command that goes out. Useful for proving which
// port a command actually lands on. Noisy - turn it back off afterwards.
#define DEBUG_MOTORS 0
static const int DEADZONE = 40; // raw stick counts ignored around centre
// Motor directions. Flip to -1 if an axis runs backwards - mirrored mountings
// are normal on a symmetric model, and this is cheaper than editing signs
// scattered through applyFrame().
static const int DIR_LEFT_TRACK = 1;
static const int DIR_RIGHT_TRACK = -1;
static const int DIR_BODY_LIFT = 1;
static const int DIR_HEAD_TILT = 1;
static const int DIR_HEAD_TURN = 1;
static const int DIR_LEFT_ARM = 1;
static const int DIR_RIGHT_ARM = 1;
// Per-axis power caps. Everything except the tracks runs into a mechanical end
// stop and there is no position feedback, so holding a direction at a stop
// stalls the motor. Lower these if an axis feels forceful.
static const int TRACK_MAX = 100; // LEGO speed range is -100..100
static const int HEAD_MAX = 45;
static const int LIFT_MAX = 60;
static const int ARM_MAX = 45;
// Track scaling: normal, L1 held (precision), R1 held (full).
static const int SCALE_NORMAL = 75;
static const int SCALE_PRECISION = 40;
static const int SCALE_FULL = 100;
// Bluepad32 button masks. Verify against your own pad with DEBUG_BUTTONS in
// the transmitter sketch if any of these seem wrong.
static const unsigned BTN_A = 0x0001; // Cross
static const unsigned BTN_B = 0x0002; // Circle
static const unsigned BTN_X = 0x0004; // Square
static const unsigned BTN_Y = 0x0008; // Triangle
static const unsigned BTN_L1 = 0x0010;
static const unsigned BTN_R1 = 0x0020;
static const unsigned DPAD_U = 0x01;
static const unsigned DPAD_D = 0x02;
static const unsigned DPAD_R = 0x04;
static const unsigned DPAD_L = 0x08;
static const unsigned long MOTOR_MIN_GAP_MS = 100; // per port
static const unsigned long HUB_MIN_GAP_MS = 25; // per hub, ~40 cmd/sec
static const unsigned long LINK_TIMEOUT_MS = 400; // failsafe
static const unsigned long RECONNECT_GAP_MS = 2000;
static const int LINK_RX_PIN = 16;
static const int LINK_TX_PIN = 17;
static const long LINK_BAUD = 115200;
static const int STATUS_LED_PIN = 2;
// =================================================================== types
struct HubLink {
Lpf2Hub hub;
const char *addr;
const char *label;
bool initialised;
unsigned long retryAt;
unsigned long lastCmdAt; // per-hub rate limit, shared across its ports
};
struct PortState {
int lastSpeed;
unsigned long lastSentAt;
};
struct Frame {
int lx, ly, rx, ry;
unsigned buttons, dpad;
int l2, r2;
};
// ================================================================= globals
static HubLink gHubs[2] = {
{Lpf2Hub(), HUB0_ADDR, "hub0", false, 0, 0},
{Lpf2Hub(), HUB1_ADDR, "hub1", false, 0, 0},
};
// Indexes: 0 rightTrack, 1 leftTrack, 2 bodyLift,
// 3 headTilt, 4 headTurn, 5 leftArm, 6 rightArm
static PortState gPort[7] = {{999, 0}, {999, 0}, {999, 0}, {999, 0},
{999, 0}, {999, 0}, {999, 0}};
static unsigned long lastFrameAt = 0;
static bool failsafeEngaged = true;
// ================================================================= helpers
// Deadzone, then rescale so the remaining travel still reaches full speed.
static int stickToSpeed(int raw, int maxSpeed) {
if (raw > -DEADZONE && raw < DEADZONE) return 0;
int sign = (raw < 0) ? -1 : 1;
long magnitude = labs((long)raw) - DEADZONE;
long scaled = (magnitude * maxSpeed) / (512L - DEADZONE);
if (scaled > maxSpeed) scaled = maxSpeed;
return sign * (int)scaled;
}
static void driveMotor(HubLink &hl, byte port, int speed, PortState &st) {
if (!hl.hub.isConnected()) return;
unsigned long now = millis();
bool stopping = (speed == 0 && st.lastSpeed != 0);
// Stops always go out immediately. Everything else is rate limited twice:
// per port, and per hub - hub 1 has four motors on it, and the per-port
// limit alone lets through more than the hub will swallow.
if (!stopping) {
if (speed == st.lastSpeed) return;
if ((now - st.lastSentAt) < MOTOR_MIN_GAP_MS) return;
if ((now - hl.lastCmdAt) < HUB_MIN_GAP_MS) return;
}
#if DEBUG_MOTORS
Serial.printf("TX %s port %u speed %d\n", hl.label, port, speed);
#endif
#if USE_TACHO_MOTORS
hl.hub.setTachoMotorSpeed(port, speed);
#else
hl.hub.setBasicMotorSpeed(port, speed);
#endif
st.lastSpeed = speed;
st.lastSentAt = now;
hl.lastCmdAt = now;
}
static void stopEverything() {
driveMotor(gHubs[0], PORT_A, 0, gPort[0]);
driveMotor(gHubs[0], PORT_B, 0, gPort[1]);
driveMotor(gHubs[0], PORT_D, 0, gPort[2]);
driveMotor(gHubs[1], PORT_A, 0, gPort[3]);
driveMotor(gHubs[1], PORT_B, 0, gPort[4]);
driveMotor(gHubs[1], PORT_C, 0, gPort[5]);
driveMotor(gHubs[1], PORT_D, 0, gPort[6]);
}
// Connect the hubs one at a time. Kicking off two scans at once upsets the
// shared NimBLE scanner and you end up with one hub connected and one sulking.
static void serviceHub(HubLink &hl) {
if (hl.hub.isConnected()) return;
if (hl.hub.isConnecting()) {
hl.hub.connectHub();
if (hl.hub.isConnected()) {
Serial.printf("[%s] connected (%s)\n", hl.label, hl.addr);
hl.hub.setLedColor(GREEN);
} else {
Serial.printf("[%s] connect failed, retrying\n", hl.label);
hl.initialised = false;
hl.retryAt = millis() + RECONNECT_GAP_MS;
}
return;
}
if (!hl.initialised && millis() >= hl.retryAt) {
Serial.printf("[%s] scanning for %s\n", hl.label, hl.addr);
hl.hub.init(std::string(hl.addr));
hl.initialised = true;
}
}
static uint8_t xorChecksum(const char *s, size_t len) {
uint8_t c = 0;
for (size_t i = 0; i < len; i++) c ^= (uint8_t)s[i];
return c;
}
static bool parseFrame(char *line, Frame &f) {
char *star = strrchr(line, '*');
if (!star) return false;
*star = '\0';
unsigned expected = 0;
if (sscanf(star + 1, "%2x", &expected) != 1) return false;
if (xorChecksum(line, strlen(line)) != (uint8_t)expected) return false;
return sscanf(line, "G,%d,%d,%d,%d,%u,%u,%d,%d",
&f.lx, &f.ly, &f.rx, &f.ry,
&f.buttons, &f.dpad, &f.l2, &f.r2) == 8;
}
// Tank drive. One input per motor - nothing is mixed.
static void applyFrame(const Frame &f) {
// Both shoulders together is the panic stop.
if ((f.buttons & BTN_L1) && (f.buttons & BTN_R1)) {
stopEverything();
return;
}
int scale = SCALE_NORMAL;
if (f.buttons & BTN_L1) scale = SCALE_PRECISION;
if (f.buttons & BTN_R1) scale = SCALE_FULL;
int leftTrack = stickToSpeed(-f.ly, TRACK_MAX) * scale / 100 * DIR_LEFT_TRACK;
int rightTrack = stickToSpeed(-f.ry, TRACK_MAX) * scale / 100 * DIR_RIGHT_TRACK;
int headTilt = ((f.dpad & DPAD_U) ? HEAD_MAX
: (f.dpad & DPAD_D) ? -HEAD_MAX : 0) * DIR_HEAD_TILT;
int headTurn = ((f.dpad & DPAD_R) ? HEAD_MAX
: (f.dpad & DPAD_L) ? -HEAD_MAX : 0) * DIR_HEAD_TURN;
// R2 raises, L2 lowers. Both analog 0..1023, so the lift stays proportional.
int bodyLift = constrain((f.r2 - f.l2) * LIFT_MAX / 1023,
-LIFT_MAX, LIFT_MAX) * DIR_BODY_LIFT;
// Square raises the left arm, Circle lowers it.
int leftArm = ((f.buttons & BTN_X) ? ARM_MAX
: (f.buttons & BTN_B) ? -ARM_MAX : 0) * DIR_LEFT_ARM;
// Cross raises the right arm, Triangle lowers it.
int rightArm = ((f.buttons & BTN_A) ? ARM_MAX
: (f.buttons & BTN_Y) ? -ARM_MAX : 0) * DIR_RIGHT_ARM;
driveMotor(gHubs[0], PORT_A, rightTrack, gPort[0]);
driveMotor(gHubs[0], PORT_B, leftTrack, gPort[1]);
driveMotor(gHubs[0], PORT_D, bodyLift, gPort[2]);
driveMotor(gHubs[1], PORT_A, headTilt, gPort[3]);
driveMotor(gHubs[1], PORT_B, headTurn, gPort[4]);
driveMotor(gHubs[1], PORT_C, leftArm, gPort[5]);
driveMotor(gHubs[1], PORT_D, rightArm, gPort[6]);
}
// ==================================================================== main
void setup() {
Serial.begin(115200);
Serial2.begin(LINK_BAUD, SERIAL_8N1, LINK_RX_PIN, LINK_TX_PIN);
pinMode(STATUS_LED_PIN, OUTPUT);
digitalWrite(STATUS_LED_PIN, LOW);
Serial.println("LEGO hub receiver starting");
}
void loop() {
// 1. Keep the hubs connected, hub0 first.
serviceHub(gHubs[0]);
if (gHubs[0].hub.isConnected()) serviceHub(gHubs[1]);
bool ready = gHubs[0].hub.isConnected() && gHubs[1].hub.isConnected();
digitalWrite(STATUS_LED_PIN, ready ? HIGH : LOW);
// 2. Pull whole lines off the link.
static char buf[128];
static size_t idx = 0;
while (Serial2.available()) {
char c = (char)Serial2.read();
if (c == '\r') continue;
if (c == '\n') {
buf[idx] = '\0';
Frame f;
if (idx > 0 && parseFrame(buf, f)) {
lastFrameAt = millis();
failsafeEngaged = false;
applyFrame(f);
}
idx = 0;
} else if (idx < sizeof(buf) - 1) {
buf[idx++] = c;
} else {
idx = 0; // overrun, throw the line away
}
}
// 3. Failsafe - link went quiet, stop before something drives off a table.
if (!failsafeEngaged && (millis() - lastFrameAt) > LINK_TIMEOUT_MS) {
Serial.println("Link timeout - stopping motors");
stopEverything();
failsafeEngaged = true;
}
}