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AP_ADC_ADS7844: changed to use spidevicedriver transaction

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Pat Hickey 2012-12-17 17:25:42 -08:00 committed by Andrew Tridgell
parent b43b003777
commit 992de8c2b9
1 changed files with 5 additions and 15 deletions
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20
libraries/AP_ADC/AP_ADC_ADS7844.cpp
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@ -56,8 +56,8 @@ extern const AP_HAL::HAL& hal;
// DO NOT CHANGE FROM 8!!
#define ADC_ACCEL_FILTER_SIZE 8
// Commands for reading ADC channels on ADS7844
static const unsigned char adc_cmd[9] =
{ 0x87, 0xC7, 0x97, 0xD7, 0xA7, 0xE7, 0xB7, 0xF7, 0x00 };
static const unsigned char adc_cmd[17] =
{ 0x87, 0, 0xC7, 0, 0x97, 0, 0xD7, 0, 0xA7, 0, 0xE7, 0, 0xB7, 0, 0xF7};
// the sum of the values since last read
static volatile uint32_t _sum[8];
@ -95,25 +95,17 @@ void AP_ADC_ADS7844::read(uint32_t tnow)
}
}
_spi->cs_assert();
// Command to read the first channel
_spi->transfer(adc_cmd[0]);
uint8_t rx[17];
_spi->transaction(adc_cmd, rx, 17);
for (ch = 0; ch < 8; ch++) {
uint16_t v;
// Read first byte
v = _spi->transfer(0) << 8;
// Read second byte and send next command
v |= _spi->transfer(adc_cmd[ch + 1]);
uint16_t v = (rx[2*ch+1] << 8) | rx[2*ch+2];
if (v & 0x8007) {
// this is a 12-bit ADC, shifted by 3 bits.
// if we get other bits set then the value is
// bogus and should be ignored
continue;
}
if (++_count[ch] == 0) {
// overflow ... shouldn't happen too often
// unless we're just not using the
@ -126,8 +118,6 @@ void AP_ADC_ADS7844::read(uint32_t tnow)
_sum[ch] += (v >> 3);
}
_spi->cs_release();
if (_spi_sem) {
bool released = _spi_sem->release((void*)&_spi_sem);
if (!released) {