5 * A Java wrapper around libftdi.
7 * Note: blocking reads are currently implemented by busy-waiting.
8 * This is really ugly. Check the linux kernel source to see how to
9 * get libftdi to do it properly.
11 * Flow control is also not properly supported.
13 public class FtdiUart {
15 private SWIGTYPE_p_ftdi_context context = example.new_ftdi_context();
17 public OutputStream getOutputStream() { return out; }
18 public InputStream getInputStream() { return in; }
20 public FtdiUart(int vendor, int product, int baud) throws IOException {
21 example.ftdi_init(context);
22 example.ftdi_usb_open(context, vendor, product);
23 example.ftdi_usb_reset(context);
24 example.ftdi_set_baudrate(context, baud);
25 example.ftdi_set_line_property(context, 8, 0, 0);
30 * Switch to uart mode, with read/write access to four CBUS lines.
31 * This function is used to write to the CBUS lines (re-invoke it to change their state).
32 * I think readPins() is used to read from them, but I'm not sure.
34 * @param cbus_mask a four-bit mask; set bit=1 to write to a CBUS line, bit=0 to read from it
35 * @param cbus_bits a four-bit mask; the bits to assert on the write-enabled CBUS lines
37 public synchronized void uart_and_cbus_mode(int cbus_mask, int cbus_bits) throws IOException {
38 example.ftdi_set_bitmode(context, (short)((cbus_mask << 4) | cbus_bits), (short)0x20);
42 * Switch to dbus mode; CBUS lines will be released (ie they will float).
43 * Use getInputStream()/getOutputStream() to read/write the eight DBUS lines.
45 * @param dbus_mask an eight-bit mask; set bit=1 to write to a DBUS line, bit=0 to read from it
47 public synchronized void dbus_mode(int dbus_mask) throws IOException {
48 example.ftdi_set_bitmode(context, (short)dbus_mask, (short)0x01);
51 /** returns the instantaneous value present on the DBUS pins */
52 public synchronized int readPins() throws IOException {
53 getOutputStream().flush();
54 byte[] b = new byte[1];
55 example.ftdi_read_pins(context, b);
59 /** purge the on-chip buffers */
60 public synchronized void purge() throws IOException {
61 example.ftdi_usb_purge_buffers(context);
64 private final InputStream in = new InputStream() {
65 public int available() throws IOException {
69 public int read() throws IOException {
70 byte[] b = new byte[1];
72 while(result==0) result = read(b, 0, 1);
75 public int read(byte[] b, int off, int len) throws IOException {
76 // FIXME: blocking reads?
80 byte[] b0 = new byte[len];
81 synchronized(FtdiUart.this) {
82 result = example.ftdi_read_data(context, b0, len);
85 System.arraycopy(b0, 0, b, off, result);
88 try { Thread.sleep(50); } catch (Exception e) { e.printStackTrace(); }
93 private final OutputStream out = new BufferedOutputStream(new OutputStream() {
94 public void write(int b) throws IOException {
95 byte[] d = new byte[1];
99 public void write(byte[] b, int off, int len) throws IOException {
100 byte[] b2 = new byte[64];
102 System.arraycopy(b, off, b2, 0, Math.min(b2.length, len));
104 synchronized(FtdiUart.this) {
105 result = example.ftdi_write_data(context, b2, Math.min(b2.length, len));