Differences

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--- spark_counter [2015/10/25 18:40] – add pictures kingkevin
+++ spark_counter [2024/01/07 17:49] (current) – external edit 127.0.0.1
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-The spark counter is a custom electricity meter.
+The spark counter is a custom electricity meter with wireless data logging capability.
 On one side I have:
@@ Line 10: / Line 10: @@
   * a [[#Raspberry Pi|Raspberry Pi single board computer]] to store the measurements in an [[https://influxdb.com/|influxDB time series database]]
   * a [[http://grafana.org/|grafana graphical monitoring tool]] to display the electricity consumption
+{{:spark_counter:dsc02371.jpg?0x300|complete spark counter}}
+**warning: the electricity meter I am presenting will only work for 1-phase 2-wire power distribution systems. I have a 3-phase 4-wire system and I was doing it wrong. This has been fixed with the [[spark abacus]].**
 ====== peacefair PZEM-004 ======
-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.
+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:
   * measures voltages 80-260 V AC
@@ Line 23: / Line 27: @@
   * provides a TTL UART port to query these values (or set an alarm so to beep when a provided power threshold is reached)
-{{:spark_counter:dsc02361.jpg?0x200|}}
+{{:spark_counter:dsc02361.jpg?0x200|PZEM-004 front}}
-{{:spark_counter:dsc02359.jpg?0x200|}}
+{{:spark_counter:dsc02359.jpg?0x200|PZEM-004 back}}
 The voltage measurement is done over the power input port.
@@ Line 31: / Line 35: @@
 A drawing on the back of the device will describe how to connect the wires.
-{{:spark_counter:dsc02328.jpg?0x200|}}
+{{:spark_counter:dsc02328.jpg?0x200|PZEM-004 opto-couplers}}
-The meter also provides a UART port to query the measured values.
+The meter also provides a UART port (using an XH-4P connector) to query the measured values.
 Two opto-couplers isolate the main power meter circuits from the TX and RX UART ports.
+^ 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 | |
+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.
 The {{:spark_counter:pzem-004.rtf|manual}} provides the corresponding commands, but lacks some information.
 The UART configurations is 9600 bps 8N1.
-Before querying the measurements, you have to set an address to the device.
+You have to set the device's address (i.e. C0 A8 01 01 = 192.168.1.1 in the examples) at least once using the 0xB4 command before querying measurements.
-Else it won't reply to the other commands.
+This address will be saved so the next time (even after power down) you can directly query measurements using the address(es) set in the device(s).
-The manual uses an IP as address (192.168.1.1 = C0 A8 01 01).
+All commands include the target device address and only the device with the specified address will respond, except for the command setting the address in the first place.
-No idea why you would set an IP for a UART address.
+This allows to query multiple devices connected to the same UART port, one after another, when they have different addresses.
+Note: the optocouplers on the Tx pin of the device have a pull-up resistor. Be sure to remove all but one when using multiple devices, else the low value of the signal will be too high for the receiver to decode the serial communication.
 The commands use the following 7 bytes message format:
@@ Line 65: / Line 80: @@
 I removed the pizeo-element to prevent this annoying sound.
-{{:spark_counter:dsc02344.jpg?0x200|}}{{:spark_counter:dsc02325.jpg?0x200|}}{{:spark_counter:dsc02327.jpg?0x200|}}
+{{:spark_counter:pzem-004-01.jpg?0x200|PZEM-004 board front}}
+{{:spark_counter:pzem-004-02.jpg?0x200|PZEM-004 board back (without buzzer)}}
 The power meter uses a single chip solution, the [[http://www.sdicmicro.com/products.html?ic=SD3004|SDIC microelectronics SD3004]] ({{:spark_counter:sd3004_datasheet_v0.2c.pdf|datasheet}}).
@@ Line 73: / Line 89: @@
 ====== ATmega328P ======
+{{:spark_counter:dsc02354.jpg?0x200|development board}}
+{{:spark_counter:dsc02365.jpg?0x200|development setup}}
 {{ :spark_counter:ic_dev_arduino_nano-30.svg?400|Arduino Nano pinout}}
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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).
-The source code is available [[https://to.do|in this git]].
+The source code is available [[https://git.cuvoodoo.info/kingkevin/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]].
 This way I learn how it works in details.
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 ====== nRF24L01+ ======
-{{:spark_counter:dsc02353.jpg?0x150|}}
+{{:spark_counter:dsc02353.jpg?0x150|nRF24L01+ module}}
 {{ :spark_counter:nrf24l01_pinout.jpg?250|nRF24L01+ pinout}}
@@ Line 103: / Line 121: @@
 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://to.do|in this git]].
+The source code is available [[https://git.cuvoodoo.info/kingkevin/spark_counter/|in this git]].
 On the [[#Raspberry Pi|computer]] side I use the [[https://github.com/TMRh20/RF24|RF24 library]].
@@ Line 110: / Line 128: @@
 ====== Raspberry Pi ======
+{{:spark_counter:dsc02375.jpg?0x200|RPi setup}}
 {{ :spark_counter:pi-gpio-header-26-sm.png?200|RPi P1 header}}
@@ Line 116: / Line 135: @@
 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://to.do|in this git]].
+The source code is available [[https://git.cuvoodoo.info/kingkevin/spark_counter/|in this git]].
-The values are then simply stored in an [[https://influxdb.com/|InfluxDB]] time series database for visualisation in [[http://grafana.org/|grafana]].
 [[http://elinux.org/RPi_Low-level_peripherals#P1_Header|RPi]] - nRF24L01+ connection:
@@ Line 129: / Line 147: @@
 | GPIO9/MISO | P1_21 | 7 | MISO |
 | GPIO24 | P1_18 | 8 | IRQ |
+The values are then simply stored in an [[https://influxdb.com/|InfluxDB]] time series database for visualisation in [[http://grafana.org/|grafana]].
+Note: there is no ARM build of grafana (armel for RPi 1, armhf for later versions).
+This is also because there is no ARM release of [[http://phantomjs.org/|PhantomJS]].
+I'm running grafana on my local computer (amd64), using the remote database on the RPi.
+{{:spark_counter:grafana.png?0x200|grafana visualization}}