Differences

This shows you the differences between two versions of the page.

--- spark_counter [2016/10/04 21:23] – [Orange Pi] moved to spark abacus kingkevin
+++ spark_counter [2017/01/18 21:14] – [peacefair PZEM-004] kingkevin
@@ Line 52: / Line 52: @@
 The {{:spark_counter:pzem-004.rtf|manual}} provides the corresponding commands, but lacks some information.
 The UART configurations is 9600 bps 8N1.
-All commands include a device address (i.e. C0 A8 01 01 = 192.168.1.1).
+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.
-Only the device with the specified address will respond.
+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).
-This allows to query multiple devices on the same UART port, one after another, when they have different addresses.
+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.
-Thus you have to set the device's address at least once using the 0xA4 command before querying measurements.
+This allows to query multiple devices connected to the same UART port, one after another, when they have different addresses.
-This address will be saved so the next time (even after power down) you can directly query measurements using the address(se) set in the device(s).
+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: