Diff: AR1021.cpp

Revision:

4:b32cf4ef45c5

diff -r 9d31a3c5013e -r b32cf4ef45c5 AR1021.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/AR1021.cpp	Fri Oct 18 12:48:58 2013 +0200
@@ -0,0 +1,526 @@
+
+/******************************************************************************
+ * Includes
+ *****************************************************************************/
+
+#include "mbed.h"
+#include "mbed_debug.h"
+
+#include "AR1021.h"
+
+/******************************************************************************
+ * Defines and typedefs
+ *****************************************************************************/
+
+#define AR1021_REG_TOUCH_THRESHOLD        (0x02)
+#define AR1021_REG_SENS_FILTER            (0x03)
+#define AR1021_REG_SAMPLING_FAST          (0x04)
+#define AR1021_REG_SAMPLING_SLOW          (0x05)
+#define AR1021_REG_ACC_FILTER_FAST        (0x06)
+#define AR1021_REG_ACC_FILTER_SLOW        (0x07)
+#define AR1021_REG_SPEED_THRESHOLD        (0x08)
+#define AR1021_REG_SLEEP_DELAY            (0x0A)
+#define AR1021_REG_PEN_UP_DELAY           (0x0B)
+#define AR1021_REG_TOUCH_MODE             (0x0C)
+#define AR1021_REG_TOUCH_OPTIONS          (0x0D)
+#define AR1021_REG_CALIB_INSETS           (0x0E)
+#define AR1021_REG_PEN_STATE_REPORT_DELAY (0x0F)
+#define AR1021_REG_TOUCH_REPORT_DELAY     (0x11)
+
+
+#define AR1021_CMD_GET_VERSION                 (0x10)
+#define AR1021_CMD_ENABLE_TOUCH                (0x12)
+#define AR1021_CMD_DISABLE_TOUCH               (0x13)
+#define AR1021_CMD_CALIBRATE_MODE              (0x14)
+#define AR1021_CMD_REGISTER_READ               (0x20)
+#define AR1021_CMD_REGISTER_WRITE              (0x21)
+#define AR1021_CMD_REGISTER_START_ADDR_REQUEST (0x22)
+#define AR1021_CMD_REGISTER_WRITE_TO_EEPROM    (0x23)
+#define AR1021_CMD_EEPROM_READ                 (0x28)
+#define AR1021_CMD_EEPROM_WRITE                (0x29)
+#define AR1021_CMD_EEPROM_WRITE_TO_REGISTERS   (0x2B)
+
+#define AR1021_RESP_STAT_OK           (0x00)
+#define AR1021_RESP_STAT_CMD_UNREC    (0x01)
+#define AR1021_RESP_STAT_HDR_UNREC    (0x03)
+#define AR1021_RESP_STAT_TIMEOUT      (0x04)
+#define AR1021_RESP_STAT_CANCEL_CALIB (0xFC)
+
+
+#define AR1021_ERR_NO_HDR      (-1000)
+#define AR1021_ERR_INV_LEN     (-1001)
+#define AR1021_ERR_INV_RESP    (-1002)
+#define AR1021_ERR_INV_RESPLEN (-1003)
+#define AR1021_ERR_TIMEOUT     (-1004)
+
+// bit 7 is always 1 and bit 0 defines pen up or down
+#define AR1021_PEN_MASK (0x81)
+
+#define AR1021_NUM_CALIB_POINTS (4)
+
+AR1021::AR1021(PinName mosi, PinName miso, PinName sck, PinName cs, PinName siq) :
+_spi(mosi, miso, sck), _cs(cs), _siq(siq), _siqIrq(siq)
+{
+    _cs = 1; // active low
+
+    _spi.format(8, 1);
+    _spi.frequency(500000);
+
+    // default calibration inset is 25 -> (25/2 = 12.5%)
+    _inset = 25;
+
+    // make sure _calibPoint has an invalid value to begin with
+    // correct value is set in calibrateStart()
+    _calibPoint = AR1021_NUM_CALIB_POINTS+1;
+
+    _x = 0;
+    _y = 0;
+    _pen = 0;
+
+    _initialized = false;
+}
+
+
+bool AR1021::read(touchCoordinate_t &coord) {
+
+    if (!_initialized) return false;
+
+    coord.x = _x * _width/4095;
+    coord.y = _y * _height/4095;
+    coord.z = _pen;
+
+    return true;
+}
+
+
+bool AR1021::init(uint16_t width, uint16_t height) {
+    int result = 0;
+    bool ok = false;
+    int attempts = 0;
+
+    _width = width;
+    _height = height;
+
+    while (1) {
+
+        do {
+            // disable touch
+            result = cmd(AR1021_CMD_DISABLE_TOUCH, NULL, 0, NULL, 0);
+            if (result != 0) {
+                debug("disable touch failed (%d)\n", result);
+                break;
+            }
+
+            char regOffset = 0;
+            int regOffLen = 1;
+            result = cmd(AR1021_CMD_REGISTER_START_ADDR_REQUEST, NULL, 0,
+                    &regOffset, &regOffLen);
+            if (result != 0) {
+                debug("register offset request failed (%d)\n", result);
+                break;
+            }
+
+            // enable calibrated coordinates
+            //                  high, low address,                        len,  value
+            char toptions[4] = {0x00, AR1021_REG_TOUCH_OPTIONS+regOffset, 0x01, 0x01};
+            result = cmd(AR1021_CMD_REGISTER_WRITE, toptions, 4, NULL, 0);
+            if (result != 0) {
+                debug("register write request failed (%d)\n", result);
+                break;
+            }
+
+            // save registers to eeprom
+            result = cmd(AR1021_CMD_REGISTER_WRITE_TO_EEPROM, NULL, 0, NULL, 0);
+            if (result != 0) {
+                debug("register write to eeprom failed (%d)\n", result);
+                break;
+            }
+
+            // enable touch
+            result = cmd(AR1021_CMD_ENABLE_TOUCH, NULL, 0, NULL, 0);
+            if (result != 0) {
+                debug("enable touch failed (%d)\n", result);
+                break;
+            }
+
+            _siqIrq.rise(this, &AR1021::readTouchIrq);
+
+            _initialized = true;
+            ok = true;
+
+        } while(0);
+
+        if (ok) break;
+
+        // try to run the initialize sequence at most 2 times
+        if(++attempts >= 2) break;
+    }
+
+
+    return ok;
+}
+
+bool AR1021::calibrateStart() {
+    bool ok = false;
+    int result = 0;
+    int attempts = 0;
+
+    if (!_initialized) return false;
+
+    _siqIrq.rise(NULL);
+
+    while(1) {
+
+        do {
+            // disable touch
+            result = cmd(AR1021_CMD_DISABLE_TOUCH, NULL, 0, NULL, 0);
+            if (result != 0) {
+                debug("disable touch failed (%d)\n", result);
+                break;
+            }
+
+            char regOffset = 0;
+            int regOffLen = 1;
+            result = cmd(AR1021_CMD_REGISTER_START_ADDR_REQUEST, NULL, 0,
+                    &regOffset, &regOffLen);
+            if (result != 0) {
+                debug("register offset request failed (%d)\n", result);
+                break;
+            }
+
+            // set insets
+            // enable calibrated coordinates
+            //                high, low address,                       len,  value
+            char insets[4] = {0x00, AR1021_REG_CALIB_INSETS+regOffset, 0x01, _inset};
+            result = cmd(AR1021_CMD_REGISTER_WRITE, insets, 4, NULL, 0);
+            if (result != 0) {
+                debug("register write request failed (%d)\n", result);
+                break;
+            }
+
+            // calibration mode
+            char calibType = 4;
+            result = cmd(AR1021_CMD_CALIBRATE_MODE, &calibType, 1, NULL, 0, false);
+            if (result != 0) {
+                debug("calibration mode failed (%d)\n", result);
+                break;
+            }
+
+            _calibPoint = 0;
+            ok = true;
+
+        } while(0);
+
+        if (ok) break;
+
+        // try to run the calibrate mode sequence at most 2 times
+        if (++attempts >= 2) break;
+    }
+
+    return ok;
+}
+
+bool AR1021::getNextCalibratePoint(uint16_t* x, uint16_t* y) {
+
+    if (!_initialized) return false;
+    if (x == NULL || y == NULL) return false;
+
+    int xInset = (_width * _inset / 100) / 2;
+    int yInset = (_height * _inset / 100) / 2;
+
+    switch(_calibPoint) {
+    case 0:
+        *x = xInset;
+        *y = yInset;
+        break;
+    case 1:
+        *x = _width - xInset;
+        *y = yInset;
+        break;
+    case 2:
+        *x = _width - xInset;
+        *y = _height - yInset;
+        break;
+    case 3:
+        *x = xInset;
+        *y = _height - yInset;
+        break;
+    default:
+        return false;
+    }
+
+    return true;
+}
+
+bool AR1021::waitForCalibratePoint(bool* morePoints, uint32_t timeout) {
+    int result = 0;
+    bool ret = false;
+
+    if (!_initialized) return false;
+
+    do {
+        if (morePoints == NULL || _calibPoint >= AR1021_NUM_CALIB_POINTS) {
+            break;
+        }
+
+        // wait for response
+        result = waitForCalibResponse(timeout);
+        if (result != 0) {
+            debug("wait for calibration response failed (%d)\n", result);
+            break;
+        }
+
+        _calibPoint++;
+        *morePoints = (_calibPoint < AR1021_NUM_CALIB_POINTS);
+
+
+        // no more points -> enable touch
+        if (!(*morePoints)) {
+
+            // wait for calibration data to be written to eeprom
+            // before enabling touch
+            result = waitForCalibResponse(timeout);
+            if (result != 0) {
+                debug("wait for calibration response failed (%d)\n", result);
+                break;
+            }
+
+
+            // clear chip-select since calibration is done;
+            _cs = 1;
+
+            result = cmd(AR1021_CMD_ENABLE_TOUCH, NULL, 0, NULL, 0);
+            if (result != 0) {
+                debug("enable touch failed (%d)\n", result);
+                break;
+            }
+
+            _siqIrq.rise(this, &AR1021::readTouchIrq);
+        }
+
+        ret = true;
+
+    } while (0);
+
+
+
+    if (!ret) {
+        // make sure to set chip-select off in case of an error
+        _cs = 1;
+        // calibration must restart if an error occurred
+        _calibPoint = AR1021_NUM_CALIB_POINTS+1;
+    }
+
+
+
+    return ret;
+}
+
+int AR1021::cmd(char cmd, char* data, int len, char* respBuf, int* respLen,
+        bool setCsOff) {
+
+    int ret = 0;
+
+    // command request
+    // ---------------
+    // 0x55 len cmd data
+    // 0x55 = header
+    // len = data length + cmd (1)
+    // data = data to send
+
+    _cs = 0;
+
+    _spi.write(0x55);
+    wait_us(50); // according to data sheet there must be an inter-byte delay of ~50us
+    _spi.write(len+1);
+    wait_us(50);
+    _spi.write(cmd);
+    wait_us(50);
+
+    for(int i = 0; i < len; i++) {
+        _spi.write(data[i]);
+        wait_us(50);
+    }
+
+
+    // wait for response (siq goes high when response is available)
+    Timer t;
+    t.start();
+    while(_siq.read() != 1 && t.read_ms() < 1000);
+
+
+    // command response
+    // ---------------
+    // 0x55 len status cmd data
+    // 0x55 = header
+    // len = number of bytes following the len byte
+    // status = status
+    // cmd = command ID
+    // data = data to receive
+
+
+    do {
+
+        if (t.read_ms() >= 1000) {
+            ret = AR1021_ERR_TIMEOUT;
+            break;
+        }
+
+        int head = _spi.write(0);
+        if (head != 0x55) {
+            ret = AR1021_ERR_NO_HDR;
+            break;
+        }
+
+        wait_us(50);
+        int len = _spi.write(0);
+        if (len < 2) {
+            ret = AR1021_ERR_INV_LEN;
+            break;
+        }
+
+        wait_us(50);
+        int status = _spi.write(0);
+        if (status != AR1021_RESP_STAT_OK) {
+            ret = -status;
+            break;
+        }
+
+        wait_us(50);
+        int cmdId = _spi.write(0);
+        if (cmdId != cmd) {
+            ret = AR1021_ERR_INV_RESP;
+            break;
+        }
+
+        if ( ((len-2) > 0 && respLen  == NULL)
+                || ((len-2) > 0 && respLen != NULL && *respLen < (len-2))) {
+            ret = AR1021_ERR_INV_RESPLEN;
+            break;
+        }
+
+        for (int i = 0; i < len-2;i++) {
+            wait_us(50);
+            respBuf[i] = _spi.write(0);
+        }
+        if (respLen != NULL) {
+            *respLen = len-2;
+        }
+
+        // make sure we wait 50us before issuing a new cmd
+        wait_us(50);
+
+    } while (0);
+
+
+
+    // disable chip-select if setCsOff is true or if an error occurred
+    if (setCsOff || ret != 0) {
+        _cs = 1;
+    }
+
+
+
+    return ret;
+}
+
+int AR1021::waitForCalibResponse(uint32_t timeout) {
+    Timer t;
+    int ret = 0;
+
+    t.start();
+
+    // wait for siq
+    while (_siq.read() != 1 &&
+            (timeout == 0 || (uint32_t)t.read_ms() < (int)timeout));
+
+
+    do {
+
+        if (timeout >  0 && (uint32_t)t.read_ms() >= timeout) {
+            ret = AR1021_ERR_TIMEOUT;
+            break;
+        }
+
+        int head = _spi.write(0);
+        if (head != 0x55) {
+            ret = AR1021_ERR_NO_HDR;
+            break;
+        }
+
+        wait_us(50);
+        int len = _spi.write(0);
+        if (len != 2) {
+            ret = AR1021_ERR_INV_LEN;
+            break;
+        }
+
+        wait_us(50);
+        int status = _spi.write(0);
+        if (status != AR1021_RESP_STAT_OK) {
+            ret = -status;
+            break;
+        }
+
+        wait_us(50);
+        int cmdId = _spi.write(0);
+        if (cmdId != 0x14) {
+            ret = AR1021_ERR_INV_RESP;
+            break;
+        }
+
+
+        // make sure we wait 50us before issuing a new cmd
+        wait_us(50);
+
+    } while (0);
+
+
+    return ret;
+}
+
+
+void AR1021::readTouchIrq() {
+    while(_siq.read() == 1) {
+
+        _cs = 0;
+
+        // touch coordinates are sent in a 5-byte data packet
+
+        int pen = _spi.write(0);
+        wait_us(50);
+
+        int xlo = _spi.write(0);
+        wait_us(50);
+
+        int xhi = _spi.write(0);
+        wait_us(50);
+
+        int ylo = _spi.write(0);
+        wait_us(50);
+
+        int yhi = _spi.write(0);
+        wait_us(50);
+
+        _cs = 1;
+
+
+        // pen down
+        if ((pen&AR1021_PEN_MASK) == (1<<7|1<<0)) {
+            _pen = 1;
+        }
+        // pen up
+        else if ((pen&AR1021_PEN_MASK) == (1<<7)){
+            _pen = 0;
+        }
+        // invalid value
+        else {
+            continue;
+        }
+
+        _x = ((xhi<<7)|xlo);
+        _y = ((yhi<<7)|ylo);
+
+    }
+}
+