Diff: bitbang.cpp

Revision:

0:e0a44db7e925

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bitbang.cpp	Thu Dec 23 15:03:51 2010 +0000
@@ -0,0 +1,238 @@
+#include "mbed.h"
+
+#include "bitbang.h"
+
+#include "main.h"
+
+#define	BB_5KHZSPEED_SETTLE         20 //~5KHz
+#define	BB_5KHZSPEED_CLOCK          100
+#define	BB_5KHZSPEED_HALFCLOCK      BB_5KHZSPEED_CLOCK/2
+
+#define	BB_50KHZSPEED_SETTLE        2 //~50KHz
+#define	BB_50KHZSPEED_CLOCK         10
+#define	BB_50KHZSPEED_HALFCLOCK     BB_50KHZSPEED_CLOCK/2
+
+#define	BB_100KHZSPEED_SETTLE       1 //~100KHz
+#define	BB_100KHZSPEED_CLOCK        5
+#define	BB_100KHZSPEED_HALFCLOCK    2
+
+#define	BB_MAXSPEED_SETTLE          0 //~400KHz
+#define	BB_MAXSPEED_CLOCK           0
+#define	BB_MAXSPEED_HALFCLOCK       0
+
+struct {
+    int pins;
+    DigitalInOut *mo;
+    DigitalInOut *mi;
+    int delay_settle;
+    int delay_clock;
+    int delay_half_clock;
+} bitbang;
+
+void bb_setup(int pins, int speed)
+{
+    bitbang.pins = pins;
+
+    if (pins == 3) {
+        bitbang.mo = &bp_mosi;
+        bitbang.mi = &bp_miso;
+    } else {
+        bitbang.mo = &bp_mosi;
+        bitbang.mi = &bp_mosi;
+    }
+
+    switch (speed) {
+    case 0:
+        bitbang.delay_settle = BB_5KHZSPEED_SETTLE;
+        bitbang.delay_clock = BB_5KHZSPEED_CLOCK;
+        bitbang.delay_half_clock = BB_5KHZSPEED_HALFCLOCK;
+        break;
+    case 1:
+        bitbang.delay_settle = BB_50KHZSPEED_SETTLE;
+        bitbang.delay_clock = BB_50KHZSPEED_CLOCK;
+        bitbang.delay_half_clock = BB_50KHZSPEED_HALFCLOCK;
+        break;
+    case 2:
+        bitbang.delay_settle = BB_100KHZSPEED_SETTLE;
+        bitbang.delay_clock = BB_100KHZSPEED_CLOCK;
+        bitbang.delay_half_clock = BB_100KHZSPEED_HALFCLOCK;
+        break;
+    default:
+        bitbang.delay_settle = BB_MAXSPEED_SETTLE;
+        bitbang.delay_clock = BB_MAXSPEED_CLOCK;
+        bitbang.delay_half_clock = BB_MAXSPEED_HALFCLOCK;
+        break;
+    }
+}
+
+void bb_h(DigitalInOut *pin, int delay)
+{
+    if (mode_config.HiZ == 0)
+        pin->mode(PullNone);
+    else
+        pin->mode(OpenDrain);
+    pin->write(1);
+    pin->output();
+    wait_us(delay);
+}
+
+void bb_l(DigitalInOut *pin, int delay)
+{
+    pin->write(0);
+    pin->output();
+    wait_us(delay);
+}
+
+void bb_pin(DigitalInOut *pin, int dir, int delay)
+{
+    pin->write(dir);
+    if (dir) {
+        if (mode_config.HiZ == 0)
+            pin->mode(PullNone);
+        else
+            pin->mode(OpenDrain);
+    }
+    pin->output();
+    wait_us(delay);
+}
+
+unsigned char bb_r(DigitalInOut *pin)
+{
+    pin->input();
+    return pin->read();
+}
+
+void bb_cs(int dir)
+{
+    bb_pin(&bp_cs, dir, bitbang.delay_settle);
+}
+
+int bb_i2c_start()
+{
+    int error = 0;
+
+    bb_h(&bp_mosi, bitbang.delay_clock);
+    bb_h(&bp_clk, bitbang.delay_clock);
+
+    if (bp_clk.read() == 0 || bp_mosi.read() == 0)
+        error = 1;
+
+    bb_l(&bp_mosi, bitbang.delay_clock);
+
+    bb_l(&bp_clk, bitbang.delay_clock);
+
+    bb_h(&bp_mosi, bitbang.delay_clock);
+
+    return error;
+}
+
+int bb_i2c_stop()
+{
+    bb_l(&bp_mosi, bitbang.delay_clock);
+    bb_l(&bp_clk, bitbang.delay_clock);
+
+    bb_h(&bp_clk, bitbang.delay_clock);
+
+    bb_h(&bp_mosi, bitbang.delay_clock);
+
+    return 0;
+}
+
+unsigned int bb_read_write_byte(unsigned int c)
+{
+    unsigned int i, bt, tem, di, dat = 0;
+
+    bt = 1 << (mode_config.numbits - 1);
+
+    tem = c;
+    for (i = 0; i < mode_config.numbits; i++) {
+        bb_pin(&bp_mosi, (tem & bt), bitbang.delay_settle);
+        bb_h(&bp_clk, bitbang.delay_clock);
+        di = bb_r(&bp_miso);
+        bb_l(&bp_clk, bitbang.delay_clock);
+
+        tem = tem << 1;
+        dat = dat << 1;
+        if (di)
+            dat++;
+    }
+    return dat;
+}
+
+void bb_write_byte(unsigned int c)
+{
+    unsigned int i, bt, tem;
+
+    bt = 1 << (mode_config.numbits - 1);
+
+    tem = c;
+    for (i = 0; i < mode_config.numbits; i++) {
+        bb_pin(&bp_mosi, tem & bt, bitbang.delay_settle);
+        bb_h(&bp_clk, bitbang.delay_clock);
+        bb_l(&bp_clk, bitbang.delay_clock);
+
+        tem = tem << 1;
+    }
+}
+unsigned int bb_read_byte()
+{
+    int i, di, dat = 0;
+
+    bb_r(&bp_mosi);
+
+    for (i = 0; i < mode_config.numbits; i++) {
+        bb_h(&bp_clk, bitbang.delay_clock);
+        di = bb_r(&bp_mosi);
+        bb_l(&bp_clk, bitbang.delay_clock);
+
+        dat = dat << 1;
+        if (di)
+            dat++;
+    }
+
+    return dat;
+}
+
+unsigned char bb_read_bit()
+{
+    unsigned char c;
+
+    bb_r(bitbang.mi);
+    bb_h(&bp_clk, bitbang.delay_clock);
+    c = bb_r(bitbang.mi);
+    bb_l(&bp_clk, bitbang.delay_clock);
+
+    return c;
+}
+
+void bb_write_bit(unsigned char c)
+{
+    bb_pin(bitbang.mo, c, bitbang.delay_settle);
+    bb_h(&bp_clk, bitbang.delay_clock);
+    bb_l(&bp_clk, bitbang.delay_clock);
+}
+
+void bb_clock_ticks(unsigned char c)
+{
+    unsigned char i;
+
+    for (i = 0; i < c; i++) {
+        bb_h(&bp_clk, bitbang.delay_clock);
+        bb_l(&bp_clk, bitbang.delay_clock);
+    }
+}
+
+void bb_mosi(unsigned char dir)
+{
+    bb_pin(bitbang.mo, dir, bitbang.delay_settle);
+}
+
+void bb_clk(unsigned char dir)
+{
+    bb_pin(&bp_clk, dir, bitbang.delay_settle);
+}
+
+unsigned char bb_miso()
+{
+    return bb_r(bitbang.mi);
+}