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//! Tier 2 features.
//!
//! These are the features included only in ADS1x14, ADS1x15
use { Ads1x1x, Error, interface, ic, ComparatorMode, ComparatorPolarity,
ComparatorLatching, Register, BitFlags };
impl<DI, IC, MODE, E> Ads1x1x<DI, IC, MODE>
where
DI: interface::WriteData<Error = E>,
IC: ic::Resolution + ic::Tier2Features
{
/// Set comparator lower threshold
pub fn set_low_threshold(&mut self, value: i16) -> Result<(), Error<E>> {
let register_value = convert_threshold::<IC, E>(value)?;
self.iface.write_register(Register::LOW_TH, register_value)
}
/// Set comparator upper threshold
pub fn set_high_threshold(&mut self, value: i16) -> Result<(), Error<E>> {
let register_value = convert_threshold::<IC, E>(value)?;
self.iface.write_register(Register::HIGH_TH, register_value)
}
/// Set comparator mode
pub fn set_comparator_mode(&mut self, mode: ComparatorMode) -> Result<(), Error<E>> {
let config;
match mode {
ComparatorMode::Traditional => config = self.config.with_low(BitFlags::COMP_MODE),
ComparatorMode::Window => config = self.config.with_high(BitFlags::COMP_MODE)
}
self.iface.write_register(Register::CONFIG, config.bits)?;
self.config = config;
Ok(())
}
/// Set comparator polarity
pub fn set_comparator_polarity(&mut self, polarity: ComparatorPolarity) -> Result<(), Error<E>> {
let config;
match polarity {
ComparatorPolarity::ActiveLow => config = self.config.with_low( BitFlags::COMP_POL),
ComparatorPolarity::ActiveHigh => config = self.config.with_high(BitFlags::COMP_POL)
}
self.iface.write_register(Register::CONFIG, config.bits)?;
self.config = config;
Ok(())
}
/// Set comparator latching
pub fn set_comparator_latching(&mut self, latching: ComparatorLatching) -> Result<(), Error<E>> {
let config;
match latching {
ComparatorLatching::Nonlatching => config = self.config.with_low( BitFlags::COMP_LAT),
ComparatorLatching::Latching => config = self.config.with_high(BitFlags::COMP_LAT)
}
self.iface.write_register(Register::CONFIG, config.bits)?;
self.config = config;
Ok(())
}
}
fn convert_threshold<IC, E>(value: i16) -> Result<u16, Error<E>>
where
IC: ic::Resolution
{
if IC::BITS == ic::ResolutionBits::_12 {
if value < -2048 || value > 2047 {
return Err(Error::InvalidInputData);
}
Ok((value << 4) as u16)
}
else {
Ok(value as u16)
}
}
#[cfg(test)]
mod tests {
use super::*;
fn assert_invalid_input_data<E>(result: Result<u16, Error<E>>) {
match result {
Err(Error::InvalidInputData) => (),
_ => panic!("InvalidInputData error was not returned.")
}
}
#[test]
fn convert_12_bits() {
assert_invalid_input_data(convert_threshold::<ic::Ads1013, ()>(2048));
assert_invalid_input_data(convert_threshold::<ic::Ads1013, ()>(-2049));
assert_eq!( 0, convert_threshold::<ic::Ads1013, ()>(0).unwrap());
assert_eq!(0x7FF0, convert_threshold::<ic::Ads1013, ()>(2047).unwrap());
assert_eq!(0x8000, convert_threshold::<ic::Ads1013, ()>(-2048).unwrap());
assert_eq!(0xFFF0, convert_threshold::<ic::Ads1013, ()>(-1).unwrap());
}
#[test]
fn convert_16_bits() {
assert_eq!(0x7FFF, convert_threshold::<ic::Ads1113, ()>(32767).unwrap());
assert_eq!(0x8000, convert_threshold::<ic::Ads1113,()>(-32768).unwrap());
}
}
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