diff options
Diffstat (limited to 'src/modules/px4iofirmware')
-rw-r--r-- | src/modules/px4iofirmware/adc.c | 53 | ||||
-rw-r--r-- | src/modules/px4iofirmware/px4io.c | 3 |
2 files changed, 26 insertions, 30 deletions
diff --git a/src/modules/px4iofirmware/adc.c b/src/modules/px4iofirmware/adc.c index 81566eb2a..2f5908ac5 100644 --- a/src/modules/px4iofirmware/adc.c +++ b/src/modules/px4iofirmware/adc.c @@ -83,6 +83,14 @@ adc_init(void) { adc_perf = perf_alloc(PC_ELAPSED, "adc"); + /* put the ADC into power-down mode */ + rCR2 &= ~ADC_CR2_ADON; + up_udelay(10); + + /* bring the ADC out of power-down mode */ + rCR2 |= ADC_CR2_ADON; + up_udelay(10); + /* do calibration if supported */ #ifdef ADC_CR2_CAL rCR2 |= ADC_CR2_RSTCAL; @@ -96,41 +104,25 @@ adc_init(void) if (rCR2 & ADC_CR2_CAL) return -1; - #endif - /* arbitrarily configure all channels for 55 cycle sample time */ - rSMPR1 = 0b00000011011011011011011011011011; + /* + * Configure sampling time. + * + * For electrical protection reasons, we want to be able to have + * 10K in series with ADC inputs that leave the board. At 12MHz this + * means we need 28.5 cycles of sampling time (per table 43 in the + * datasheet). + */ + rSMPR1 = 0b00000000011011011011011011011011; rSMPR2 = 0b00011011011011011011011011011011; - /* XXX for F2/4, might want to select 12-bit mode? */ - rCR1 = 0; - - /* enable the temperature sensor / Vrefint channel if supported*/ - rCR2 = -#ifdef ADC_CR2_TSVREFE - /* enable the temperature sensor in CR2 */ - ADC_CR2_TSVREFE | -#endif - 0; - -#ifdef ADC_CCR_TSVREFE - /* enable temperature sensor in CCR */ - rCCR = ADC_CCR_TSVREFE; -#endif + rCR2 |= ADC_CR2_TSVREFE; /* enable the temperature sensor / Vrefint channel */ /* configure for a single-channel sequence */ rSQR1 = 0; rSQR2 = 0; - rSQR3 = 0; /* will be updated with the channel each tick */ - - /* power-cycle the ADC and turn it on */ - rCR2 &= ~ADC_CR2_ADON; - up_udelay(10); - rCR2 |= ADC_CR2_ADON; - up_udelay(10); - rCR2 |= ADC_CR2_ADON; - up_udelay(10); + rSQR3 = 0; /* will be updated with the channel at conversion time */ return 0; } @@ -141,11 +133,12 @@ adc_init(void) uint16_t adc_measure(unsigned channel) { + perf_begin(adc_perf); /* clear any previous EOC */ - if (rSR & ADC_SR_EOC) - rSR &= ~ADC_SR_EOC; + rSR = 0; + (void)rDR; /* run a single conversion right now - should take about 60 cycles (a few microseconds) max */ rSQR3 = channel; @@ -158,7 +151,6 @@ adc_measure(unsigned channel) /* never spin forever - this will give a bogus result though */ if (hrt_elapsed_time(&now) > 100) { - debug("adc timeout"); perf_end(adc_perf); return 0xffff; } @@ -166,6 +158,7 @@ adc_measure(unsigned channel) /* read the result and clear EOC */ uint16_t result = rDR; + rSR = 0; perf_end(adc_perf); return result; diff --git a/src/modules/px4iofirmware/px4io.c b/src/modules/px4iofirmware/px4io.c index d8ebb43e9..d03b64809 100644 --- a/src/modules/px4iofirmware/px4io.c +++ b/src/modules/px4iofirmware/px4io.c @@ -210,6 +210,9 @@ user_start(int argc, char *argv[]) /* initialise the control inputs */ controls_init(); + /* set up the ADC */ + adc_init(); + /* start the FMU interface */ interface_init(); |