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--- spark_abacus [2017/01/20 21:09] – [Orange Pi] kingkevin
+++ spark_abacus [2017/01/23 19:34] – adjust summary kingkevin
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-The spark abacus is a custom electricity meter with wireless data logging capability.
+The spark abacus is a custom electricity meter monitoring system.
-It's a follow-up to the [[spark_counter|spark counter]] for a 3-phase 4-wire mains electricity power distribution installation.
+It's a follow-up of the [[spark_counter|spark counter]], but for a 3-phase 4-wire mains electricity power distribution installation.
 ====== electricity meters ======
@@ Line 23: / Line 23: @@
 Compared to the [[spark_counter#peacefair_pzem-004|PZEM-004]] it comes without display and buzzer, but is much smaller.
 Else it uses the same design and chip.
+===== DDM100TC =====
+The [[http://www.china-huabang.com/en/product-show.asp?id=31&tt=101|DDM100TC]] (you can find it under different brands) is a 3-phase 4-wire electricity meter.
+{{:spark_abacus:ddm100tc-01.jpg?0x200|DDM100TC module, front side}}
+{{:spark_abacus:ddm100tc-02.jpg?0x200|DDM100TC module, connectivity}}
+The meter provides:
+  * 1 LCD to show the energy used in kWh (with a precision od 0.1 kWh)
+  * 3 LEDs to show which phase powered (L1, L2, L3)
+  * 1 LED to show the direction to the current (reverse if REV is on)
+  * 1 LED to show impulses as energy is used
+  * 1 S0 interface to output impulses as energy is used
+The S0 interface (labelled TEST on the side) allows me to collect the energy used on my micro-controller.
+Connect the + side (pin 8) to a positive voltage (i.e. +5V), an the - side (pin 7) to an input (with a pull-down resistor).
+Each impulse will generate a high signal (+2.5V in my case) on - for ~ 90 ms.
+The number of impulses indicates the energy used, and the time interval between impulses indicates the current power consumption.
+I chose one with a high impulse rate of 1600 impulses/kWh (= 1 impulse for every 0.625 Wh).
+{{:spark_abacus:ddm100tc-03.jpg?0x150|DDM100TC module, LCD board, front side}}
+{{:spark_abacus:ddm100tc-06.jpg?0x150|DDM100TC module, LCD board, back side}}
+{{:spark_abacus:ddm100tc-04.jpg?0x150|DDM100TC module, meter board, front side}}
+{{:spark_abacus:ddm100tc-05.jpg?0x150|DDM100TC module, meter board, back side}}
+There is also the DDM100TCR model with an RS-485 interface, but I couldn't find any documentation about the protocol messages, thus I wasn't interested in this feature.
+===== Eastron SDM120-Modbus =====
+The [[http://www.eastrongroup.com/|Eastron]] [[http://eastrongroupco.hk02.057321.com/productsview/14.html|SDM120-Modbus]] is a slim 1-phase 2-wire electricity meter.
+{{:spark_abacus:sdm120-02.jpg?0x200|SDM120 front}}
+{{:spark_abacus:sdm120-01.jpg?0x200|SDM120 side}}
+{{:spark_abacus:sdm120-03.jpg?0x200|SDM120 board back}}
+{{:spark_abacus:sdm120-04.jpg?0x200|SDM120 board side}}
+{{:spark_abacus:sdm120-05.jpg?0x200|SDM120 board side}}
+Be aware as numerous SDM120 models exist, combining following options:
+  * in-line current measurement or using a current sensing coil (CT)
+  * with electro-mechanical display or LCD, sometimes with backlight
+  * only with 2 pulse outputs, or with additional MBus or Modbus interface
+I chose the {{:spark_abacus:sdm120-modbus_user_manual_scan.pdf|SDM120 model}} (one per phase) since I wanted to learn about the RS-485 interface and Modbus protocol.
+The [[http://eastrongroupco.hk02.057321.com/data/uploads/Eastron_SDM120-Modbus_protocol_V2_3_(1).pdf|corresponding Modbus document]] ({{:spark_abacus:sdm120-modbus_protocol_v2.1.pdf |older v2.1}}) lists the registers containing the measurements (input registers) and configuration (holding registers).
+This document also explains the Modbus protocol, but I rather recommend to read the one for the [[http://eastrongroupco.hk02.057321.com/data/uploads/Eastron_SDM630MV_CT_protocol_V1_0_.pdf|SDM630]] since it contains more information, most importantly the timing between messages.
 ====== EPS8266 ======
@@ Line 98: / Line 145: @@
 ====== Orange Pi ======
+{{:spark_abacus:opi-01.jpg?0x200|Orange Pi PC, front side}}
+{{:spark_abacus:opi-02.jpg?0x200|Orange Pi PC, without heat sink}}
+{{:spark_abacus:opi-03.jpg?0x200|Orange Pi PC, back side}}
 The [[http://www.orangepi.org/orangepipc/|Orange Pi PC]] is a cheap [[http://www.aliexpress.com/item/Orange-Pi-PC-ubuntu-linux-and-android-mini-PC-Beyond-and-Compatible-with-Raspberry-Pi-2/32448079125.html|$15 alternative]] to the Raspberry Pi 2.
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 I am only using this SBC a cheap computer rather than hardware platform.
 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.
+On it I've installed an [[https://www.influxdata.com/|InfluxDB]] time-series database to store the values (using the HTTP API), and [[http://grafana.org/|Grafana]] to visualize them.