#include <ao.h>
#include "ao_ms5607.h"
-struct ms5607_prom {
- uint16_t reserved;
- uint16_t sens;
- uint16_t off;
- uint16_t tcs;
- uint16_t tco;
- uint16_t tref;
- uint16_t tempsens;
- uint16_t crc;
-};
-
static struct ms5607_prom ms5607_prom;
+static uint8_t ms5607_configured;
static void
ao_ms5607_start(void) {
ao_ms5607_stop();
}
-static uint16_t
-ao_ms5607_prom_read(uint8_t addr)
+static uint8_t
+ao_ms5607_crc(uint8_t *prom)
{
- uint8_t cmd = AO_MS5607_PROM_READ(addr);
- uint8_t d[2];
- uint16_t v;
-
- ao_ms5607_start();
- ao_spi_send(&cmd, 1, AO_MS5607_SPI_INDEX);
- ao_spi_recv(d, 2, AO_MS5607_SPI_INDEX);
- ao_ms5607_stop();
- return ((uint16_t) d[0] << 8) | (uint16_t) d[1];
+ uint8_t crc_byte = prom[15];
+ uint8_t cnt;
+ uint16_t n_rem = 0;
+ uint16_t crc_read;
+ uint8_t n_bit;
+
+ prom[15] = 0;
+ for (cnt = 0; cnt < 16; cnt++) {
+ n_rem ^= prom[cnt];
+ for (n_bit = 8; n_bit > 0; n_bit--) {
+ if (n_rem & 0x8000)
+ n_rem = (n_rem << 1) ^ 0x3000;
+ else
+ n_rem = (n_rem << 1);
+ }
+ }
+ n_rem = (n_rem >> 12) & 0xf;
+ prom[15] = crc_byte;
+ return n_rem;
}
static void
-ao_ms5607_init_chip(void) {
+ao_ms5607_prom_read(struct ms5607_prom *prom)
+{
uint8_t addr;
- uint16_t *prom;
+ uint8_t crc;
+ uint16_t *r;
+
+ r = (uint16_t *) prom;
+ for (addr = 0; addr < 8; addr++) {
+ uint8_t cmd = AO_MS5607_PROM_READ(addr);
+ ao_ms5607_start();
+ ao_spi_send(&cmd, 1, AO_MS5607_SPI_INDEX);
+ ao_spi_recv(r, 2, AO_MS5607_SPI_INDEX);
+ ao_ms5607_stop();
+ r++;
+ }
+ crc = ao_ms5607_crc((uint8_t *) prom);
+ if (crc != (((uint8_t *) prom)[15] & 0xf))
+ printf ("MS5607 PROM CRC error (computed %x actual %x)\n", crc, (((uint8_t *) prom)[15] & 0xf));
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /* Byte swap */
+ r = (uint16_t *) prom;
+ for (addr = 0; addr < 8; addr++) {
+ uint16_t t = *r;
+ *r++ = (t << 8) | (t >> 8);
+ }
+#endif
+}
+static void
+ao_ms5607_setup(void)
+{
+ if (ms5607_configured)
+ return;
+ ms5607_configured = 1;
ao_ms5607_reset();
- prom = &ms5607_prom.reserved;
-
- for (addr = 0; addr <= 7; addr++)
- prom[addr] = ao_ms5607_prom_read(addr);
- printf ("reserved: 0x%x\n", ms5607_prom.reserved);
- printf ("sens: 0x%x\n", ms5607_prom.sens);
- printf ("off: 0x%x\n", ms5607_prom.off);
- printf ("tcs: 0x%x\n", ms5607_prom.tcs);
- printf ("tco: 0x%x\n", ms5607_prom.tco);
- printf ("tref: 0x%x\n", ms5607_prom.tref);
- printf ("tempsens: 0x%x\n", ms5607_prom.tempsens);
- printf ("crc: 0x%x\n", ms5607_prom.crc);
+ ao_ms5607_prom_read(&ms5607_prom);
}
static uint32_t
return ((uint32_t) reply[0] << 16) | ((uint32_t) reply[1] << 8) | (uint32_t) reply[2];
}
-static void
-ao_ms5607_dump(void)
+void
+ao_ms5607_sample(struct ao_ms5607_sample *sample)
{
uint8_t addr;
uint32_t D1, D2;
int64_t SENS;
int32_t P;
+ ao_ms5607_setup();
+
D2 = ao_ms5607_convert(AO_MS5607_CONVERT_D2_4096);
printf ("Conversion D2: %d\n", D2);
D1 = ao_ms5607_convert(AO_MS5607_CONVERT_D1_4096);
int32_t TEMPM = TEMP - 2000;
int64_t OFF2 = (61 * (int64_t) TEMPM * (int64_t) TEMPM) >> 4;
int64_t SENS2 = 2 * (int64_t) TEMPM * (int64_t) TEMPM;
+ if (TEMP < 1500) {
+ int32_t TEMPP = TEMP + 1500;
+ int64_t TEMPP2 = TEMPP * TEMPP;
+ OFF2 = OFF2 + 15 * TEMPP2;
+ SENS2 = SENS2 + 8 * TEMPP2;
+ }
+ TEMP -= T2;
+ OFF -= OFF2;
+ SENS -= SENS2;
}
P = ((((int64_t) D1 * SENS) >> 21) - OFF) >> 15;
-
- printf ("Temperature: %d\n", TEMP);
- printf ("Pressure %d\n", P);
+ sample->temp = TEMP;
+ sample->pres = P;
+}
+
+static void
+ao_ms5607_dump(void)
+{
+ struct ao_ms5607_sample sample;
+
+ ao_ms5607_sample(&sample);
+ printf ("Temperature: %d\n", sample.temp);
+ printf ("Pressure %d\n", sample.pres);
}
__code struct ao_cmds ao_ms5607_cmds[] = {
- { ao_ms5607_init_chip, "i\0Init MS5607" },
{ ao_ms5607_dump, "p\0Display MS5607 data" },
{ 0, NULL },
};
void
ao_ms5607_init(void)
{
+ ms5607_configured = 0;
ao_cmd_register(&ao_ms5607_cmds[0]);
ao_spi_init_cs(AO_MS5607_CS_GPIO, (1 << AO_MS5607_CS));
}