diff options
| author | Keith Packard <keithp@keithp.com> | 2013-06-15 01:20:49 -0700 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2013-06-15 01:21:45 -0700 |
| commit | be9ee9ed2d041c4ab4e77ee2010fe3c7a1ca6597 (patch) | |
| tree | 2ec07a0e0e03157589b51e6d5d67a2e01972af83 /src | |
| parent | 7361371190bf3805b6d0414e61f697aca7c7cff1 (diff) | |
altos/lpc: Filter ADC inputs
They're amazingly noisy on EasyMini, so just filter them as the only
thing we use them for is battery and pyro numbers.
Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/lpc/ao_adc_lpc.c | 39 | ||||
| -rw-r--r-- | src/lpc/ao_arch_funcs.h | 6 | ||||
| -rw-r--r-- | src/lpc/lpc.h | 7 |
3 files changed, 34 insertions, 18 deletions
diff --git a/src/lpc/ao_adc_lpc.c b/src/lpc/ao_adc_lpc.c index 25a121b5..40173aa4 100644 --- a/src/lpc/ao_adc_lpc.c +++ b/src/lpc/ao_adc_lpc.c @@ -91,47 +91,58 @@ (AO_ADC_6 << 6) | \ (AO_ADC_7 << 7)) -#define AO_ADC_CLKDIV (AO_LPC_SYSCLK / 4500000 - 1) +#define AO_ADC_CLKDIV (AO_LPC_SYSCLK / 4500000) -static uint8_t ao_adc_ready; +static uint8_t ao_adc_ready; + +static uint16_t ao_adc_prev[AO_NUM_ADC]; + +#define sample(id) do { \ + uint16_t p = *prev; \ + uint16_t v = lpc_adc.dr[id]; \ + p -= p >> 4; \ + p += v >> 4; \ + *prev++ = p; \ + *out++ = p >> 1; \ + } while (0) void lpc_adc_isr(void) { uint32_t stat = lpc_adc.stat; uint16_t *out; + uint16_t *prev; - lpc_adc.cr = ((AO_ADC_MASK << LPC_ADC_CR_SEL) | - (AO_ADC_CLKDIV << LPC_ADC_CR_CLKDIV) | - (0 << LPC_ADC_CR_BURST) | - (LPC_ADC_CR_CLKS_11 << LPC_ADC_CR_CLKS)); + /* Turn off burst mode */ + lpc_adc.cr = 0; lpc_adc.stat = 0; /* Store converted values in packet */ out = (uint16_t *) &ao_data_ring[ao_data_head].adc; + prev = ao_adc_prev; #if AO_ADC_0 - *out++ = lpc_adc.dr[0] >> 1; + sample(0); #endif #if AO_ADC_1 - *out++ = lpc_adc.dr[1] >> 1; + sample(1); #endif #if AO_ADC_2 - *out++ = lpc_adc.dr[2] >> 1; + sample(2); #endif #if AO_ADC_3 - *out++ = lpc_adc.dr[3] >> 1; + sample(3); #endif #if AO_ADC_4 - *out++ = lpc_adc.dr[4] >> 1; + sample(4); #endif #if AO_ADC_5 - *out++ = lpc_adc.dr[5] >> 1; + sample(5); #endif #if AO_ADC_6 - *out++ = lpc_adc.dr[6] >> 1; + sample(6); #endif #if AO_ADC_7 - *out++ = lpc_adc.dr[7] >> 1; + sample(7); #endif AO_DATA_PRESENT(AO_DATA_ADC); diff --git a/src/lpc/ao_arch_funcs.h b/src/lpc/ao_arch_funcs.h index 179b2f4d..1bbb14f5 100644 --- a/src/lpc/ao_arch_funcs.h +++ b/src/lpc/ao_arch_funcs.h @@ -61,12 +61,10 @@ #define analog_func(id) lpc_token_evaluator_2(LPC_IOCONF_FUNC_AD,id) #define ao_enable_analog(port,bit,id) do { \ - uint32_t _mode; \ ao_enable_port(port); \ lpc_gpio.dir[port] &= ~(1 << bit); \ - _mode = ((analog_func(id) << LPC_IOCONF_FUNC) | \ - (0 << LPC_IOCONF_ADMODE)); \ - lpc_ioconf.analog_reg(port,bit) = _mode; \ + lpc_ioconf.analog_reg(port,bit) = ((analog_func(id) << LPC_IOCONF_FUNC) | \ + (0 << LPC_IOCONF_ADMODE)); \ } while (0) #define ARM_PUSH32(stack, val) (*(--(stack)) = (val)) diff --git a/src/lpc/lpc.h b/src/lpc/lpc.h index 49034c1c..d66f0dd0 100644 --- a/src/lpc/lpc.h +++ b/src/lpc/lpc.h @@ -1169,6 +1169,13 @@ extern struct lpc_adc lpc_adc; #define LPC_ADC_CR_CLKS_6 5 #define LPC_ADC_CR_CLKS_5 6 #define LPC_ADC_CR_CLKS_4 7 +#define LPC_ADC_CR_START 24 +#define LPC_ADC_CR_START_NONE 0 +#define LPC_ADC_CR_START_NOW 1 + +#define LPC_ADC_GDR_CHN 24 +#define LPC_ADC_GDR_OVERRUN 30 +#define LPC_ADC_GDR_DONE 31 #define LPC_ADC_INTEN_ADINTEN 0 #define LPC_ADC_INTEN_ADGINTEN 8 |