/* * receiver.ino -- UART -> two LEGO Powered Up hubs (ESP32 "B") * * Model: Johnny 5 (Short Circuit) MOC - "Evolved" control scheme. * 7 motors across 2 Technic hubs, plus 2 GPIO-driven LED circuits. * * 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. * * Wiring to the transmitter board: * RX GPIO16 <- TX GPIO17 on transmitter * TX GPIO17 -> RX GPIO16 on transmitter * GND -> GND (mandatory - common ground) * * LED circuits (see LED_1_PIN / LED_2_PIN below): * GPIO25 -> resistor -> LED pair -> GND * GPIO26 -> resistor -> LED pair -> GND * Pins output 3.3V, not 3V. ~12mA per pin is comfortable, 40mA is the hard * limit. Anything drawing more than ~20mA per circuit needs a transistor. * * 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 left arm // B left track B head turn // C (free) C head tilt // D body lift 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; // LED circuits. Safe GPIOs - no boot strapping or flash duties, unlike 0, 2, // 12 and 15. static const int LED_1_PIN = 25; // Circle toggles this pair static const int LED_2_PIN = 26; // Triangle toggles this pair // Technic / Control+ motors are tacho motors -> leave this at 1. #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. 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_UP_MAX = 45; static const int ARM_DOWN_MAX = 30; // gravity helps on the way down // Track speed, toggled by Cross. static const int SPEED_SLOW = 50; static const int SPEED_FAST = 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 BTN_L3 = 0x0100; // left stick click static const unsigned BTN_R3 = 0x0200; // right stick click static const unsigned DPAD_U = 0x01; static const unsigned DPAD_D = 0x02; static const unsigned DPAD_R = 0x04; static const unsigned DPAD_L = 0x08; // Triggers rest at 0 and are noisy near the bottom of their travel. static const int TRIGGER_DEADZONE = 60; 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 follow physical ports, not functions: // 0 hub0/A 1 hub0/B 2 hub0/D // 3 hub1/A 4 hub1/B 5 hub1/C 6 hub1/D 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; // Latched state, changed on button press rather than while held. static int gTrackSpeed = SPEED_SLOW; static bool gLed1On = false; static bool gLed2On = false; static unsigned gPrevButtons = 0; // ================================================================= 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; } // Analog trigger, 0..1023, to a 0..maxSpeed power with a deadzone at the bottom. static int triggerToSpeed(int raw, int maxSpeed) { if (raw <= TRIGGER_DEADZONE) return 0; long scaled = ((long)(raw - TRIGGER_DEADZONE) * maxSpeed) / (1023L - TRIGGER_DEADZONE); if (scaled > maxSpeed) scaled = maxSpeed; return (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; } // Latching controls fire once per press, not continuously while held. Frames // arrive at ~50 Hz, so without edge detection a single press would toggle // twenty times. static void handleLatchingButtons(unsigned buttons) { unsigned pressed = buttons & ~gPrevButtons; gPrevButtons = buttons; if (pressed & BTN_A) { // Cross - alternate track speed gTrackSpeed = (gTrackSpeed == SPEED_FAST) ? SPEED_SLOW : SPEED_FAST; Serial.printf("track speed %d%%\n", gTrackSpeed); } if (pressed & BTN_B) { // Circle - LED pair 1 gLed1On = !gLed1On; digitalWrite(LED_1_PIN, gLed1On ? HIGH : LOW); } if (pressed & BTN_Y) { // Triangle - LED pair 2 gLed2On = !gLed2On; digitalWrite(LED_2_PIN, gLed2On ? HIGH : LOW); } } // Tank drive. One input per motor - nothing is mixed. static void applyFrame(const Frame &f) { handleLatchingButtons(f.buttons); // Square is the panic stop. LEDs are left alone - they are not motion. if (f.buttons & BTN_X) { stopEverything(); return; } int leftTrack = stickToSpeed(-f.ly, TRACK_MAX) * gTrackSpeed / 100 * DIR_LEFT_TRACK; int rightTrack = stickToSpeed(-f.ry, TRACK_MAX) * gTrackSpeed / 100 * DIR_RIGHT_TRACK; // L1 / R1 swing the head while held. int headTurn = ((f.buttons & BTN_R1) ? HEAD_MAX : (f.buttons & BTN_L1) ? -HEAD_MAX : 0) * DIR_HEAD_TURN; // D-pad: up/down lifts the body, left/right tilts the head. Both move // while held. int bodyLift = ((f.dpad & DPAD_U) ? LIFT_MAX : (f.dpad & DPAD_D) ? -LIFT_MAX : 0) * DIR_BODY_LIFT; int headTilt = ((f.dpad & DPAD_R) ? HEAD_MAX : (f.dpad & DPAD_L) ? -HEAD_MAX : 0) * DIR_HEAD_TILT; // Arms: analog trigger raises proportionally, stick click lowers. int leftRaise = triggerToSpeed(f.l2, ARM_UP_MAX); int rightRaise = triggerToSpeed(f.r2, ARM_UP_MAX); int leftArm = ((f.buttons & BTN_L3) ? -ARM_DOWN_MAX : leftRaise) * DIR_LEFT_ARM; int rightArm = ((f.buttons & BTN_R3) ? -ARM_DOWN_MAX : rightRaise) * 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, leftArm, gPort[3]); driveMotor(gHubs[1], PORT_B, headTurn, gPort[4]); driveMotor(gHubs[1], PORT_C, headTilt, 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); pinMode(LED_1_PIN, OUTPUT); pinMode(LED_2_PIN, OUTPUT); digitalWrite(LED_1_PIN, LOW); digitalWrite(LED_2_PIN, LOW); Serial.println("LEGO hub receiver starting (Johnny 5 Evolved)"); } 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; } }