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en:tech:sensorlogger [2020/10/15 17:17] – [Features] bullar | en:tech:sensorlogger [2020/10/15 18:30] (current) – external edit 127.0.0.1 | ||
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==== Protocol ==== | ==== Protocol ==== | ||
- | If you dare to use the IT + protocol, you will find some sources (see links). The sensor | + | If you dare to use the IT+ protocol, you will find some sources (see links). The sensor |
- | always | + | It should also be noted that no negative values are transmitted, |
- | It should also be noted that no negative values are transmitted, | + | |
<code C> | <code C> | ||
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====Hardware==== | ====Hardware==== | ||
- | {{: | + | {{: |
- | {{: | + | {{: |
---- | ---- | ||
- | The following components are used as hardware: | + | The following components are used in the hardware: |
* 868MHz receiver module with PCB antenna | * 868MHz receiver module with PCB antenna | ||
- | * ATMEL ATmega1284P + ENC28J60 for 100base-T | + | * ATMEL ATmega1284P + ENC28J60 for 100base-T |
* microSD adapter | * microSD adapter | ||
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There is an inexpensive 868MHz RFM12 module for receiving (and, if you want, also for sending). | There is an inexpensive 868MHz RFM12 module for receiving (and, if you want, also for sending). | ||
It is a '' | It is a '' | ||
- | Communication takes place via a normal SPI interface in 16-bit transfer. The setting options are so versatile that you get desperate at the beginning until you finally | + | Communication takes place via a normal SPI interface in 16-bit transfer. The setting options are so versatile that you get desperate at the beginning until you finally |
<code C> | <code C> | ||
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=== PCB === | === PCB === | ||
{{: tech: sensorlogger_board.png? | {{: tech: sensorlogger_board.png? | ||
- | The PCB was matched to the SP 2000 SW housing from STRAPUBOX. So that everything simply fits into SMD where it makes sense. | + | The PCB was matched to the SP 2000 SW housing from STRAPUBOX. So that everything simply fits into SMD components are used where it makes sense. |
When it comes to sockets (Power / Ethernet), I'm still a fan of thru-hole - because of the stability. The soldering took place again in the pizza pan as described in the c't Hacks. | When it comes to sockets (Power / Ethernet), I'm still a fan of thru-hole - because of the stability. The soldering took place again in the pizza pan as described in the c't Hacks. | ||
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An antenna must also be connected to the RFM12 module. Usually 1/4 lamba so about 8.3cm. But since there was still space on the PCB, I dared to try a PCB variant in a meandering structure. There is also a nice design note from Texas Instruments (DN024). The result was a bit off, however, because the <m> epsilon_r </m> of my favorite PCB maker turned out a bit different in reality. The maximum gain was about 790MHz and could then be reduced to 868MHz with a final -6dB gain. This means that reception through concrete ceilings or walls is also feasible. | An antenna must also be connected to the RFM12 module. Usually 1/4 lamba so about 8.3cm. But since there was still space on the PCB, I dared to try a PCB variant in a meandering structure. There is also a nice design note from Texas Instruments (DN024). The result was a bit off, however, because the <m> epsilon_r </m> of my favorite PCB maker turned out a bit different in reality. The maximum gain was about 790MHz and could then be reduced to 868MHz with a final -6dB gain. This means that reception through concrete ceilings or walls is also feasible. | ||
==== Software ==== | ==== Software ==== | ||
- | The software was created with AVR STudio 6 and AVR-Dragon | + | The software was created with AVR STudio 6 and an AVR-Dragon as a debugger. |
==== Outlook ==== | ==== Outlook ==== | ||
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==== Links ==== | ==== Links ==== | ||
- | * [[http:// | + | * [[http:// |
- | * [[http:// | + | * [[http:// |
- | * [[http:// | + | * [[http:// |
* [[http:// | * [[http:// | ||
* [[http:// | * [[http:// |