diff options
| -rw-r--r-- | gyroscope.c | 27 | ||||
| -rw-r--r-- | i2c.c | 52 | ||||
| -rw-r--r-- | i2c.h | 15 |
3 files changed, 34 insertions, 60 deletions
diff --git a/gyroscope.c b/gyroscope.c index 0f932c2..23fa197 100644 --- a/gyroscope.c +++ b/gyroscope.c @@ -41,23 +41,16 @@ void gyroscopeInit () { /* XXX: make nonblocking */ void gyroscopeStart () { - /* XXX: implement multi-write */ - /* disable power-down-mode */ - if (!twWrite (L3GD20, L3GD20_CTRLREG1, 0b00001111)) { - printf ("cannot start write\n"); - } - sleepwhile (twr.status == TWST_WAIT); - printf ("final twi status was %i\n", twr.status); - - /* enable drdy interrupt */ - if (!twWrite (L3GD20, L3GD20_CTRLREG3, 0b00001000)) { - printf ("cannot start write\n"); - } - sleepwhile (twr.status == TWST_WAIT); - printf ("final twi status was %i\n", twr.status); + /* configuration: + * disable power-down-mode + * defaults + * enable drdy interrupt + * select 500dps + */ + uint8_t data[] = {0b00001111, 0b0, 0b00001000, 0b00010000}; - /* select 500dps */ - if (!twWrite (L3GD20, L3GD20_CTRLREG4, 0b00010000)) { + if (!twRequest (TWM_WRITE, L3GD20, L3GD20_CTRLREG1, data, + sizeof (data)/sizeof (*data))) { printf ("cannot start write\n"); } sleepwhile (twr.status == TWST_WAIT); @@ -68,7 +61,7 @@ bool gyroscopeRead () { if (drdy) { drdy = false; - if (!twReadMulti (L3GD20, 0x28, (uint8_t *) val, 6)) { + if (!twRequest (TWM_READ, L3GD20, 0x28, (uint8_t *) val, 6)) { printf ("cannot start read\n"); } @@ -52,39 +52,17 @@ void twInit () { /* high-level write */ -bool twWrite (const uint8_t address, const uint8_t subaddress, - const uint8_t data) { +bool twRequest (const twMode mode, const uint8_t address, + const uint8_t subaddress, uint8_t * const data, const uint8_t count) { /* do not start if request is pending */ if (twr.status == TWST_WAIT) { return false; } - twr.mode = TWM_WRITE; + twr.mode = mode; twr.address = address; twr.subaddress = subaddress; twr.data = data; - twr.step = 0; - twr.status = TWST_WAIT; - /* wait for stop finish */ - while (TW_STATUS != 0xf8); - twStartRaw (); - - return true; -} - -/* high-level read for multiple bytes/addresses - */ -bool twReadMulti (const uint8_t address, const uint8_t subaddress, - uint8_t * const retData, const uint8_t count) { - /* do not start if request is pending */ - if (twr.status == TWST_WAIT) { - return false; - } - - twr.mode = TWM_READ_MULTI; - twr.address = address; - twr.subaddress = subaddress; - twr.retData = retData; twr.count = count; twr.i = 0; twr.step = 0; @@ -104,6 +82,7 @@ static void twIntWrite () { if (TW_STATUS == TW_START) { twWriteRaw (twr.address | TW_WRITE); twFlushRaw (); + ++twr.step; } else { twr.status = TWST_ERR; } @@ -111,8 +90,10 @@ static void twIntWrite () { case 1: if (TW_STATUS == TW_MT_SLA_ACK) { - twWriteRaw (twr.subaddress); + /* write subaddress, enable auto-increment */ + twWriteRaw ((1 << 7) | twr.subaddress); twFlushRaw (); + ++twr.step; } else { twr.status = TWST_ERR; } @@ -120,8 +101,12 @@ static void twIntWrite () { case 2: if (TW_STATUS == TW_MT_DATA_ACK) { - twWriteRaw (twr.data); + twWriteRaw (twr.data[twr.i]); + ++twr.i; twFlushRaw (); + if (twr.i >= twr.count) { + ++twr.step; + } } else { twr.status = TWST_ERR; } @@ -140,12 +125,11 @@ static void twIntWrite () { printf ("nope\n"); break; } - ++twr.step; } /* handle interrupt, read request */ -static void twIntReadMulti () { +static void twIntRead () { switch (twr.step) { case 0: if (TW_STATUS == TW_START) { @@ -201,7 +185,7 @@ static void twIntReadMulti () { case 5: if (TW_STATUS == TW_MR_DATA_ACK) { - twr.retData[twr.i] = TWDR; + twr.data[twr.i] = TWDR; ++twr.i; if (twr.i < twr.count-1) { /* read another byte, not the last one */ @@ -220,7 +204,7 @@ static void twIntReadMulti () { case 6: if (TW_STATUS == TW_MR_DATA_NACK) { /* receive final byte, send stop */ - twr.retData[twr.i] = TWDR; + twr.data[twr.i] = TWDR; twStopRaw (); twr.status = TWST_OK; } else { @@ -229,7 +213,7 @@ static void twIntReadMulti () { break; default: - printf ("twIntReadMulti: nope\n"); + printf ("twIntRead: nope\n"); break; } } @@ -240,8 +224,8 @@ ISR(TWI_vect) { twIntWrite (); break; - case TWM_READ_MULTI: - twIntReadMulti (); + case TWM_READ: + twIntRead (); break; default: @@ -4,7 +4,7 @@ typedef enum { TWM_INVALID = 0, TWM_WRITE, - TWM_READ_MULTI, + TWM_READ, } twMode; typedef enum { @@ -19,11 +19,10 @@ typedef struct { twMode mode; uint8_t address; uint8_t subaddress; - uint8_t data; uint8_t step; - /* read data store */ - uint8_t *retData; - /* number of bytes to be read */ + /* pointer to read/write data */ + uint8_t *data; + /* number of bytes to be read/written */ uint8_t count; /* current byte */ uint8_t i; @@ -40,9 +39,7 @@ extern volatile twReq twr; #include <stdbool.h> void twInit (); -bool twWrite (const uint8_t address, const uint8_t subaddress, - const uint8_t data); -bool twReadMulti (const uint8_t address, const uint8_t subaddress, - uint8_t * const retData, const uint8_t count); +bool twRequest (const twMode mode, const uint8_t address, + const uint8_t subaddress, uint8_t * const data, const uint8_t count); #endif /* TW_H */ |