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 = FtdiUartNative.new_ftdi_context();
17 public FtdiUart(int vendor, int product, int baud) throws IOException {
18 FtdiUartNative.ftdi_init(context);
19 FtdiUartNative.ftdi_usb_open(context, vendor, product);
20 FtdiUartNative.ftdi_usb_reset(context);
21 FtdiUartNative.ftdi_set_baudrate(context, baud);
22 FtdiUartNative.ftdi_set_line_property(context, 8, 0, 0);
23 FtdiUartNative.ftdi_setflowctrl(context, (1<<8));
27 /** the output stream to the uart or dbus pins (depending on mode) */
28 public OutputStream getOutputStream() { return out; }
30 /** the input stream from the uart or dbus pins (depending on mode) */
31 public InputStream getInputStream() { return in; }
34 * Switch to uart mode, with read/write access to four CBUS lines.
35 * This function is used to write to the CBUS lines (re-invoke it to change their state).
36 * I think readPins() is used to read from them, but I'm not sure.
38 * @param cbus_mask a four-bit mask; set bit=1 to write to a CBUS line, bit=0 to read from it
39 * @param cbus_bits a four-bit mask; the bits to assert on the write-enabled CBUS lines
41 public synchronized void uart_and_cbus_mode(int cbus_mask, int cbus_bits) throws IOException {
42 FtdiUartNative.ftdi_set_bitmode(context, (short)((cbus_mask << 4) | cbus_bits), (short)0x20);
43 FtdiUartNative.ftdi_setflowctrl(context, (1<<8));
47 * Switch to dbus mode; CBUS lines will be released (ie they will float).
48 * Use getInputStream()/getOutputStream() to read/write the eight DBUS lines.
50 * @param dbus_mask an eight-bit mask; set bit=1 to write to a DBUS line, bit=0 to read from it
52 public synchronized void dbus_mode(int dbus_mask) throws IOException {
53 FtdiUartNative.ftdi_set_bitmode(context, (short)dbus_mask, (short)0x01);
56 public synchronized void setBitRate(int bitRate) throws IOException {
57 FtdiUartNative.ftdi_set_baudrate(context, bitRate);
60 /** returns the instantaneous value present on the DBUS pins */
61 public synchronized int readPins() throws IOException {
62 getOutputStream().flush();
63 byte[] b = new byte[1];
64 FtdiUartNative.ftdi_read_pins(context, b);
68 /** purge the on-chip buffers */
69 public synchronized void purge() throws IOException {
70 FtdiUartNative.ftdi_usb_purge_buffers(context);
73 private final InputStream in = new InputStream() {
74 public int available() throws IOException {
78 public int read() throws IOException {
79 byte[] b = new byte[1];
81 while(result==0) result = read(b, 0, 1);
84 public int read(byte[] b, int off, int len) throws IOException {
85 // FIXME: blocking reads?
89 byte[] b0 = new byte[len];
90 synchronized(FtdiUart.this) {
91 result = FtdiUartNative.ftdi_read_data(context, b0, len);
94 System.arraycopy(b0, 0, b, off, result);
97 try { Thread.sleep(50); } catch (Exception e) { e.printStackTrace(); }
102 private final OutputStream out = new BufferedOutputStream(new OutputStream() {
103 public void write(int b) throws IOException {
104 byte[] d = new byte[1];
108 public void write(byte[] b, int off, int len) throws IOException {
109 byte[] b2 = new byte[64];
111 System.arraycopy(b, off, b2, 0, Math.min(b2.length, len));
113 synchronized(FtdiUart.this) {
114 result = FtdiUartNative.ftdi_write_data(context, b2, Math.min(b2.length, len));