Differences

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--- spark_counter [2015/12/08 16:27] – [Orange Pi] kingkevin
+++ spark_counter [2016/02/21 10:40] – add warning kingkevin
@@ Line 12: / Line 12: @@
 {{:spark_counter:dsc02371.jpg?0x300|complete spark counter}}
+**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.**
 ====== peacefair PZEM-004 ======
@@ Line 37: / Line 39: @@
 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.
+^ 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.
@@ Line 152: / Line 164: @@
 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:
-  * 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
 Since I'll only use it as server I decided to go with debian jessie minimal.
 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.
+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.