env_sensor
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env_sensor [2015/04/15 23:02] – [Connect a SHT21 / SHT25] breaker27 | env_sensor [2018/02/18 19:37] – [Partlist (in buildup order)] breaker27 | ||
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| 1 | PCB Generic Midi 1 | | | 1 | PCB Generic Midi 1 | | ||
| 1 | Resistor 560R green-blue-brown | | 1 | Resistor 560R green-blue-brown | ||
- | | 1 | Resistor 150k 0,1% brown-green-black | + | | 1 | Resistor 150k 0,1% brown-green-black |
- | | 1 | Resistor 330k 0,1% orange-orange-black | + | | 1 | Resistor 330k 0,1% orange-orange-black |
| 1 | Resistor 1M brown-black-green | | 1 | Resistor 1M brown-black-green | ||
| 1 | Resistor 100k brown-black-yellow | | 1 | Resistor 100k brown-black-yellow | ||
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Even if the SHT15 uses partly the same pins as the I2C sensors, they can be connected and used in parallel! | Even if the SHT15 uses partly the same pins as the I2C sensors, they can be connected and used in parallel! | ||
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+ | ===== Connect a button or switch ===== | ||
+ | |||
+ | You can use any of the available I/O pins as a digital input. You have different options regarding the pull-up resistor and therefore the power consumption. The behaviour can be configured with the EEPROM editor. | ||
+ | |||
+ | - If you want to measure the state **only cyclic** after the RFM12 wake-up timeout, it's recommended to use the **internal pull-up resistor** and connect the button / switch against ground. The pull-up is only switched on a very short time when the device is on and therefore draws much less power than connecting a physical pull-up which is connected all the time. | ||
+ | - If you want to detect the botton / switch / pin state **immediately**, | ||
+ | * If you use the internal resistor with its resistance of around 22 kOhm, it would draw about 135µA, which is a lot. This is only recommended if you power your device with a power supply (not batteries). | ||
+ | * The second option is to connect an external (physical) pull-up resistor of 1 MOhm to 10 MOhm. One 1 MOhm pull-up (for one I/O pin) would draw around 3µA (at 3V battery voltage), so this is also noticeable compared to the sleep power consumption of around 1,2µA. Depending on your batteries, amount of I/O pins used as digital input and the percentage of the pin being pulled down by the button/..., you may try a risistor with a higher value like 10 MOhm. | ||
===== Connect a SHT15 ===== | ===== Connect a SHT15 ===== | ||
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{{sht25_size.jpg? | {{sht25_size.jpg? | ||
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+ | < | ||
===== Connect a DS7505 ===== | ===== Connect a DS7505 ===== | ||
env_sensor.txt · Last modified: 2018/02/18 19:39 by breaker27