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spark_counter [2015/12/08 16:27] – [Orange Pi] kingkevin | spark_counter [2016/09/30 17:29] – update links kingkevin |
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{{:spark_counter:dsc02371.jpg?0x300|complete spark counter}} | {{:spark_counter:dsc02371.jpg?0x300|complete spark counter}} |
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| **warning: the electricity meter I am presenting will only work for 1 phase 2 wires power distribution systems. I have a 3 phases 4 wires system and I am doing it wrong.** |
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====== peacefair PZEM-004 ====== | ====== peacefair PZEM-004 ====== |
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The [[http://www.aliexpress.com/wholesale?catId=0&SearchText=peacefair|peacefair]] [[http://www.aliexpress.com/wholesale?catId=0&SearchText=peacefair+pzem-004|PZEM-004]] is a simple power meter ({{:spark_counter:peacefair_pzem-004_porduct.pdf|datasheet}}). | The [[https://www.aliexpress.com/store/1773456|peacefair]] [[https://www.aliexpress.com/store/product/PEACEFAIR-AC-100A-Digital-LCD-power-meter-power-energy-Volt-Ammeter-with-shell-4-led-panel/1773456_32320321777.html|PZEM-004]] is a simple power meter ({{:spark_counter:peacefair_pzem-004_porduct.pdf|datasheet}}). |
It: | It: |
* measures voltages 80-260 V AC | * measures voltages 80-260 V AC |
The meter also provides a UART port to query the measured values. | The meter also provides a UART port to query the measured values. |
Two opto-couplers isolate the main power meter circuits from the TX and RX UART ports. | Two opto-couplers isolate the main power meter circuits from the TX and RX UART ports. |
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| ^ UART ^ PZEM-004 ^ note ^ |
| | 5V | VDD | 3.3V is not enough | |
| | TX | RX | the UART pin needs to be able to sink ~4 mA | |
| | RX | TX | the UART pin needs to be idle high | |
| | GND | GND | | |
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| I used a CP2102 based USB to UART converter. |
| CH340 based USB to UART converters will not work (it seems to not be able to sink enough current). |
| And when using the Arduino you should not use the USB port (for serial), since that interferes with the UART signals. |
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The {{:spark_counter:pzem-004.rtf|manual}} provides the corresponding commands, but lacks some information. | The {{:spark_counter:pzem-004.rtf|manual}} provides the corresponding commands, but lacks some information. |
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USART to query the power meter, SPI to communicate with the nRF24L01+, and the nRF24L01+ protocol are implemented in C (using a lot of interrupts). | USART to query the power meter, SPI to communicate with the nRF24L01+, and the nRF24L01+ protocol are implemented in C (using a lot of interrupts). |
The source code is available [[https://git.cuvoodoo.info/kingkevin/spark_counter/tree/master|in this git]]. | The source code is available [[https://git.cuvoodoo.info/spark_counter/|in this git]]. |
I prefer directly writing in the registers as described in the [[http://www.atmel.com/images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet_Complete.pdf|datasheet]] rather than using an [[https://www.arduino.cc/en/Main/Software|abstract IDE]] and [[https://github.com/TMRh20/RF24|libraries]]. | I prefer directly writing in the registers as described in the [[http://www.atmel.com/images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet_Complete.pdf|datasheet]] rather than using an [[https://www.arduino.cc/en/Main/Software|abstract IDE]] and [[https://github.com/TMRh20/RF24|libraries]]. |
This way I learn how it works in details. | This way I learn how it works in details. |
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On the [[#ATmega328P|micro-controller]] side I implemented the complete SPI-based protocol using the [[https://www.nordicsemi.com/eng/content/download/2726/34069/file/nRF24L01P_Product_Specification_1_0.pdf|datasheet]]. | On the [[#ATmega328P|micro-controller]] side I implemented the complete SPI-based protocol using the [[https://www.nordicsemi.com/eng/content/download/2726/34069/file/nRF24L01P_Product_Specification_1_0.pdf|datasheet]]. |
The source code is available [[https://git.cuvoodoo.info/kingkevin/spark_counter/tree/master|in this git]]. | The source code is available [[https://git.cuvoodoo.info/spark_counter/|in this git]]. |
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On the [[#Raspberry Pi|computer]] side I use the [[https://github.com/TMRh20/RF24|RF24 library]]. | On the [[#Raspberry Pi|computer]] side I use the [[https://github.com/TMRh20/RF24|RF24 library]]. |
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To receive the measurements I used a [[#nRF24L01+|nRF24L01+ transceiver]] with the [[https://github.com/TMRh20/RF24|RF24 library]]. | To receive the measurements I used a [[#nRF24L01+|nRF24L01+ transceiver]] with the [[https://github.com/TMRh20/RF24|RF24 library]]. |
The source code is available [[https://git.cuvoodoo.info/kingkevin/spark_counter/tree/master|in this git]]. | The source code is available [[https://git.cuvoodoo.info/spark_counter/|in this git]]. |
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[[http://elinux.org/RPi_Low-level_peripherals#P1_Header|RPi]] - nRF24L01+ connection: | [[http://elinux.org/RPi_Low-level_peripherals#P1_Header|RPi]] - nRF24L01+ connection: |
Also only Android supports the video hardware acceleration currently. | Also only Android supports the video hardware acceleration currently. |
The official [[http://www.orangepi.org/downloadresources/|images]] are quite old (e.g. Android 4.2.2), but there are a bit newer images made available by the community: | The official [[http://www.orangepi.org/downloadresources/|images]] are quite old (e.g. Android 4.2.2), but there are a bit newer images made available by the community: |
* such as [[http://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=755|Android]], with weird [[http://www.orangepi.org/Docs/SDcardinstallation.html#Install_Android_OS_image|installation process]] | * [[http://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=755|Android]] (often ROMs from other Allwinner based products), with a weird [[http://www.orangepi.org/Docs/SDcardinstallation.html#Install_Android_OS_image|installation process]] |
* various [[http://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=342|linux]] distributions | * various [[http://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=342|linux]] distributions |
Since I'll only use it as server I decided to go with debian jessie minimal. | Since I'll only use it as server I decided to go with debian jessie minimal. |
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The pin header is the same as the [[http://www.raspberry-projects.com/pi/pi-hardware/raspberry-pi-2-model-b/rpi2-model-b-io-pins|40-pin Raspberry Pi]]. | The pin header is the same as the [[http://www.raspberry-projects.com/pi/pi-hardware/raspberry-pi-2-model-b/rpi2-model-b-io-pins|40-pin Raspberry Pi]]. |
| The SPI port to connect the nRF24L01 is also available over ''/dev/spi''. |
| But else this board is not really worth spending time on. |
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| Also don't forget to put a heat sink on the CPU, else they will be slowed down quite often because of the high temperatures. |