Sony Block Camera Controlled by an RC Transmitter

This project uses one channel from an RC receiver to control the optical zoom of a Sony FCB EX11D block camera. An Arduino reads the receiver pulse and sends Sony VISCA commands to the camera.

The complete camera control experiment.

Hardware

• Sony FCB EX11D camera block
• Arduino Pro Mini running at 3.3 V
• Spektrum DX6i transmitter
• Spektrum AR6200 receiver
• Composite video monitor
• Regulated camera and controller power supplies

The FCB EX11D provides 10 times optical zoom and an NTSC composite video output. Sony specifies a camera supply of 6 to 12 V DC. The serial control port uses VISCA at CMOS 5 V signal levels. The camera accepts 9600, 19200 or 38400 bit/s. This example uses 9600 bit/s.

Connections

• RC receiver elevator signal to Arduino digital pin 3
• Arduino serial transmit to camera RxD
• Arduino ground, receiver ground and camera signal ground connected together
• Camera composite video output to the monitor
• Camera power from a regulated 6 to 12 V supply

Check the voltage of the receiver signal before connecting it to a 3.3 V Arduino. Receivers powered from 5 V do not all use the same signal voltage. Add a divider or a proper level shifter if the pulse exceeds the input limit of the controller.

The camera RxD input recognizes a 3.3 V Arduino high level. The camera TxD output is a 5 V CMOS signal, so it must not be connected directly to a 3.3 V input. This simple example sends commands only and leaves camera TxD disconnected. A complete controller should use level conversion and read the VISCA acknowledgement and completion packets.

Prototype wiring for the receiver, controller and camera.

How the control works

A normal RC channel produces a pulse close to 1000 through 2000 microseconds. The center is normally near 1500 microseconds. The program measures one pulse, applies a dead band around the center and sends one of three VISCA packets: zoom in, zoom out or stop.

The code below reads the pulse once per loop, sends a packet only when the requested state changes and keeps every VISCA packet together.

#include <SoftwareSerial.h>

const byte rcPin = 3;
const byte cameraRxPin = 10;  // Not connected in this transmit only example
const byte cameraTxPin = 11;  // Connect to camera RxD

SoftwareSerial cameraSerial(cameraRxPin, cameraTxPin);

const byte addressSet[] = {0x88, 0x30, 0x01, 0xFF};
const byte interfaceClear[] = {0x88, 0x01, 0x00, 0x01, 0xFF};
const byte zoomIn[] = {0x81, 0x01, 0x04, 0x07, 0x23, 0xFF};
const byte zoomOut[] = {0x81, 0x01, 0x04, 0x07, 0x33, 0xFF};
const byte zoomStop[] = {0x81, 0x01, 0x04, 0x07, 0x00, 0xFF};

enum ZoomState { STOPPED, TELE, WIDE };
ZoomState lastState = STOPPED;

template <size_t N>
void sendPacket(const byte (&packet)[N]) {
  cameraSerial.write(packet, N);
}

void setup() {
  pinMode(rcPin, INPUT);
  cameraSerial.begin(9600);
  delay(500);
  sendPacket(addressSet);
  delay(100);
  sendPacket(interfaceClear);
  delay(100);
  sendPacket(zoomStop);
}

void loop() {
  unsigned long pulse = pulseIn(rcPin, HIGH, 25000UL);
  ZoomState nextState = STOPPED;

  if (pulse != 0) {
    if (pulse > 1550) nextState = TELE;
    else if (pulse < 1400) nextState = WIDE;
  }

  if (nextState != lastState) {
    if (nextState == TELE) sendPacket(zoomIn);
    else if (nextState == WIDE) sendPacket(zoomOut);
    else sendPacket(zoomStop);
    lastState = nextState;
  }
}

The values 0x23 and 0x33 request variable speed tele and wide movement at speed 3. Sony allows speed values from 0 through 7 in these commands.

The camera sends standard composite video to the monitor.

Practical improvements

For use on a moving platform, add a signal loss timeout, read VISCA replies, strain relieve every connector and use a separate regulator with enough current for the lens motor. Set the transmitter failsafe so loss of the RC signal stops the zoom. A three position switch gives more predictable control than a spring centered stick.

Sony lists the FCB EX11D at about 95 g before the controller and wiring. Measure the complete installed payload and update the aircraft balance before flight.

Hackaday featured this project in Controlling A Block Camera With An RC Transmitter. The command details and signal levels come from the Sony FCB EX11D technical documentation.

Additional project photographs