mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
121 lines
4.5 KiB
Markdown
121 lines
4.5 KiB
Markdown
|
|
[](https://github.com/marketplace/actions/arduino_ci)
|
|
[](https://github.com/RobTillaart/DS1821/actions/workflows/arduino-lint.yml)
|
|
[](https://github.com/RobTillaart/DS1821/actions/workflows/jsoncheck.yml)
|
|
[](https://github.com/RobTillaart/DS1821/issues)
|
|
|
|
[](https://github.com/RobTillaart/DS1821/blob/master/LICENSE)
|
|
[](https://github.com/RobTillaart/DS1821/releases)
|
|
[](https://registry.platformio.org/libraries/robtillaart/DS1821)
|
|
|
|
|
|
# DS1821
|
|
|
|
Arduino library for DS1821 temperature sensor (experimental).
|
|
|
|
|
|
## Description
|
|
|
|
The DS1821 is a temperature sensor that uses the oneWire protocol.
|
|
This library supports one sensor per pin.
|
|
As this library is tested minimally please consider it experimental.
|
|
|
|
The sensor is hard to get however still available on the Internet.
|
|
|
|
|
|
## Interface (temperature sensor)
|
|
|
|
```cpp
|
|
#include "DS1821.h"
|
|
```
|
|
|
|
The interface of the library is an async interface so there are no blocking calls.
|
|
|
|
The return value **DS1821_RESET_ERROR == -999** means that the oneWire bus failed to reset.
|
|
|
|
- **DS1821(OneWire\* ow)** initializes the library with a reference to a oneWire object.
|
|
See examples.
|
|
- **int requestTemperature()** this call will trigger a conversion of temperature,
|
|
however it does not read the temperature. May return **DS1821_RESET_ERROR**.
|
|
- **int requestContinuous()**
|
|
- **int stopContinuous()**
|
|
- **int conversionReady()** when the conversion is ready it returns 1, else 0.
|
|
May return **DS1821_RESET_ERROR**
|
|
- **float readTemperature()** when conversion is ready, one can fetch the temperature.
|
|
May return **DS1821_RESET_ERROR**
|
|
- **int error()** read the last error.
|
|
|
|
The low / high functions can be used to monitor if a threshold has been exceeded
|
|
between reads of the temperature.
|
|
|
|
- **int setLow(int8_t lo)** set low (OFF) threshold temperature.
|
|
- **int getLow()** read back from configuration.
|
|
- **int setHigh(int8_t hi)** set high (ON) threshold temperature.
|
|
- **int getHigh()** read back from configuration.
|
|
- **int getHighFlag()** flag is set if temperature has exceeded high threshold.
|
|
- **int clrHighFlag()** reset the high threshold flag.
|
|
- **int getLowFlag()** flag is set if temperature has exceeded low threshold.
|
|
- **int clrLowFlag()** reset the low threshold flag.
|
|
|
|
|
|
## Interface (thermostat)
|
|
|
|
Please read datasheet.
|
|
|
|
The DS1821 can be setup as a stand-alone thermostat with a high level and low level.
|
|
In this mode the DS1821 uses the **DQ** pin to switch a device ON when the high level
|
|
is exceeded and switches OFF when the low level is reached.
|
|
This prevents too frequent toggling which would happen if only one temperature was used.
|
|
To configure the thermostat mode please check the example.
|
|
|
|
The library provides the following functions for configuring the Thermostat mode
|
|
|
|
- **int setOneWireMode(uint8_t VDD, uint8_t DQ)**
|
|
This function puts a DS1821 in Thermostat mode back into oneWire mode.
|
|
DQ must be the same as oneWire(pin).
|
|
VDD is the voltage controlling pin of the sensor.
|
|
- **int setThermostatMode()** sets the flag in the config register to start in
|
|
Thermostat mode next restart.
|
|
|
|
The polarity functions are also available in temperature sensor mode,
|
|
however they have no effect in that mode.
|
|
|
|
- **int setPolarity(int activeState)** When in thermostat mode the DQ pin controls e.g.
|
|
a fan or a motor. ActivState defines which value is ON and OFF.
|
|
- **int getPolarity()** reads back polarity from the device.
|
|
|
|
The Low / High values set in sensor mode gives the DS1821 the thresholds
|
|
to toggle the DQ line in the thermostat mode.
|
|
|
|
|
|
## Operation
|
|
|
|
See examples.
|
|
|
|
|
|
## Future
|
|
|
|
#### Must
|
|
|
|
- update documentation
|
|
|
|
#### Should
|
|
|
|
#### Could
|
|
|
|
#### Wont
|
|
|
|
- updates only on request
|
|
- Get new sensors to test test test...
|
|
- merge clrLowFlag() into getLowFlag() ? high idem?
|
|
|
|
|
|
## Support
|
|
|
|
If you appreciate my libraries, you can support the development and maintenance.
|
|
Improve the quality of the libraries by providing issues and Pull Requests, or
|
|
donate through PayPal or GitHub sponsors.
|
|
|
|
Thank you,
|
|
|