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pmod:pmodhygro:reference-manual [2021/05/14 23:03] – ↷ Page moved from reference:pmod:pmodhygro:reference-manual to pmod:pmodhygro:reference-manual Arthur Brownpmod:pmodhygro:reference-manual [2022/10/04 11:38] (current) – external edit 127.0.0.1
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 ===== Interfacing with the Pmod===== ===== Interfacing with the Pmod=====
-The Pmod HYGRO communicates with the host board via the [[pmod:communication_protocols:I2C|I²C protocol]]. By first sending the 7-bit I²C address of 1000000 (0x40) and then a read/write bit (high/low logic level, respectively), followed by the register address of interest at a maximum clock frequency of 400 kHz, users can both configure and read from the Pmod HYGRO. [[:reference:pmod:pmodhygro:#pinout_table|Header J2]] on the Pmod HYGRO passes through all of the signals present on the main [[:reference:pmod:pmodhygro:#pinout_table|Header J1]] to allow for the daisy chaining of multiple I²C compatible modules.+The Pmod HYGRO communicates with the host board via the [[pmod:communication_protocols:I2C|I²C protocol]]. By first sending the 7-bit I²C address of 1000000 (0x40) and then a read/write bit (high/low logic level, respectively), followed by the register address of interest at a maximum clock frequency of 400 kHz, users can both configure and read from the Pmod HYGRO. [[pmod:pmodhygro:#pinout_table|Header J2]] on the Pmod HYGRO passes through all of the signals present on the main [[pmod:pmodhygro:#pinout_table|Header J1]] to allow for the daisy chaining of multiple I²C compatible modules.
  
 ==== Configuration Register ==== ==== Configuration Register ====
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 |  14-bit resolution  |  6.50 ms  | || |  14-bit resolution  |  6.50 ms  | ||
  
-Upon device power-up, the Pmod HYGRO requires at least 15 ms prior to being able to perform a measurement. To perform a measurement, users need to configure (or accept) the measurement settings in the Configuration Register, and then trigger the measurement(s) by sending an I²C write transaction along with the address pointer set to the appropriate register. After waiting the [[:reference:pmod:pmodhygro:reference-manual#temperature_and_humidity_registers|appropriate conversion times]], users may then perform a read transaction, taking advantage of the auto-incrementing pointer address for reading both the temperature and humidity registers. After the data has been read, users need to wait at least one full second before performing another read transaction to avoid internal heating of the sensor and the distortion of the measured temperature and humidity levels.+Upon device power-up, the Pmod HYGRO requires at least 15 ms prior to being able to perform a measurement. To perform a measurement, users need to configure (or accept) the measurement settings in the Configuration Register, and then trigger the measurement(s) by sending an I²C write transaction along with the address pointer set to the appropriate register. After waiting the [[pmod:pmodhygro:reference-manual#temperature_and_humidity_registers|appropriate conversion times]], users may then perform a read transaction, taking advantage of the auto-incrementing pointer address for reading both the temperature and humidity registers. After the data has been read, users need to wait at least one full second before performing another read transaction to avoid internal heating of the sensor and the distortion of the measured temperature and humidity levels.
  
 Note that if a write transaction is performed on either the temperature (address 0x00) or humidity (address 0x01) registers during a conversion, the current conversion will be aborted and a new one started. If a read is performed during a conversion, the Pmod HYGRO will respond back with a [[learn/fundamentals/communication-protocols/i2c/start|NACK]] indicating the measurement result is not yet available. The typical time that it takes the output of the humidity sensor to show 63% of a step change in humidity is 15 seconds. Note that if a write transaction is performed on either the temperature (address 0x00) or humidity (address 0x01) registers during a conversion, the current conversion will be aborted and a new one started. If a read is performed during a conversion, the Pmod HYGRO will respond back with a [[learn/fundamentals/communication-protocols/i2c/start|NACK]] indicating the measurement result is not yet available. The typical time that it takes the output of the humidity sensor to show 63% of a step change in humidity is 15 seconds.
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 The schematics of the %%Pmod HYGRO%% are available {{reference:pmod:pmodhygro:pmodHYGRO_sch.pdf|here}}. Additional information about the humidity sensor including communication modes and specific timings of the chip can be found by checking out its datasheet [[http://www.ti.com/lit/ds/symlink/hdc1080.pdf|here]]. The schematics of the %%Pmod HYGRO%% are available {{reference:pmod:pmodhygro:pmodHYGRO_sch.pdf|here}}. Additional information about the humidity sensor including communication modes and specific timings of the chip can be found by checking out its datasheet [[http://www.ti.com/lit/ds/symlink/hdc1080.pdf|here]].
  
-More specific information about how to use the %%Pmod HYGRO%% can be found by checking out the additional resources on the Pmod HYGRO [[reference:pmod:pmodhygro:start#additional_resources|Resource Center]]. Example code demonstrating how to get information from the %%Pmod HYGRO%% can be found on its Resource Center [[reference:pmod:pmodhygro:start#example_projects|here]]. +More specific information about how to use the %%Pmod HYGRO%% can be found by checking out the additional resources on the Pmod HYGRO [[pmod:pmodhygro:start#additional_resources|Resource Center]]. Example code demonstrating how to get information from the %%Pmod HYGRO%% can be found on its Resource Center [[pmod:pmodhygro:start#example_projects|here]]. 
  
 If you have any questions or comments about the %%Pmod HYGRO%%, feel free to post them under the appropriate section ("Add-on Boards") of the [[https://forum.digilentinc.com/|Digilent Forum]]. If you have any questions or comments about the %%Pmod HYGRO%%, feel free to post them under the appropriate section ("Add-on Boards") of the [[https://forum.digilentinc.com/|Digilent Forum]].
  
 {{tag>pmod pmodhygro humidity reference-manual}} {{tag>pmod pmodhygro humidity reference-manual}}