Skip to content

System_Architecture.md

Latest commit

 

History

History
49 lines (36 loc) · 2.12 KB

System_Architecture.md

File metadata and controls

49 lines (36 loc) · 2.12 KB
Raw

Legacy ESP-NOW Joystick Transmitter

Reference: Controller.ino. This sketch remains in the repository for the older ESP-NOW control path. Current BaseLink uses a direct Bluepad32 gamepad and has no ESP-NOW receiver.

Hardware and build

Signal GPIO
Joystick X 34, ADC1
Joystick Y 35, ADC1
Joystick switch 32, pull-up, active LOW
Status LED 2

Power the joystick at 3.3 V with common ground. ADC1 is used because Wi-Fi occupies ADC2 resources. The sketch uses the stock ESP32 Arduino 3.x core and the wifi_tx_info_t send-callback signature. Serial diagnostics run at 115200 baud.

Set receiverMAC[] to the intended legacy receiver's STA address. The transmitter configures an unencrypted peer on channel 0.

Sampling and processing

  1. On boot, average 64 samples per axis at 5 ms spacing to capture the resting center.
  2. Every 20 ms, average four ADC readings per axis.
  3. Subtract the calibrated center and divide by JOY_RANGE=2048.
  4. Apply an EMA with JOY_SMOOTH=0.7.
  5. Apply a 0.10 deadzone and rescale the remaining range.
  6. Clamp to -1 through 1, then scale forward by 5.0 and steering by 1.0.
  7. Poll the switch. A press edge toggles the enable flag; no explicit debounce interval is implemented.
  8. Send the packed packet when the peer was added successfully.

Packet

typedef struct __attribute__((packed)) {
    float forward;
    float steering;
    uint8_t enable;
} JoystickPacket;

The packed payload is 9 bytes: two 32-bit floats and one enable byte. Forward uses the legacy -5 through +5 target-offset units; steering is -1 through +1. The receiver must agree on layout, scaling, and radio channel.

Diagnostics

  • Boot prints the local STA MAC, target MAC, center calibration, and peer status.
  • ESP-NOW initialization failure halts the sketch.
  • Peer-add failure leaves it running without transmission.
  • Failed sends toggle the status LED.
  • Every 200 ms, serial prints forward, steering, and enable values.

For the active gamepad mapping and pairing instructions, see BaseLink README.