Updated PZEM004T documentation and small fixes. (#1328)

code/espurna/sensor.ino

@@ -282,7 +282,7 @@ void _sensorInitCommands() {
             DEBUG_MSG_P(PSTR("[SENSOR] PZEM004T\n"));
             unsigned char dev_count = pzem004t_sensor->getAddressesCount();
             for(unsigned char dev = 0; dev < dev_count; dev++) {
-                DEBUG_MSG_P(PSTR("Device %d Address %s\n"), dev, pzem004t_sensor->getAddress(dev).c_str());
+                DEBUG_MSG_P(PSTR("Device %d/%s\n"), dev, pzem004t_sensor->getAddress(dev).c_str());
             }
             DEBUG_MSG_P(PSTR("+OK\n"));
         } else if(e->argc == 2) {
@@ -299,7 +299,7 @@ void _sensorInitCommands() {
         }
     });
     settingsRegisterCommand(F("PZ.RESET"), [](Embedis* e) {
-         if(e->argc > 2) {
+        if(e->argc > 2) {
             DEBUG_MSG_P(PSTR("-ERROR: Wrong arguments\n"));
         } else {
             unsigned char init = e->argc == 2 ? String(e->argv[1]).toInt() : 0;
@@ -308,7 +308,7 @@ void _sensorInitCommands() {
             for(unsigned char dev = init; dev < limit; dev++) {
                 float offset = pzem004t_sensor->resetEnergy(dev);
                 setSetting("pzEneTotal", dev, offset);
-                DEBUG_MSG_P(PSTR("Device %d Address %s - Offset: %s\n"), dev, pzem004t_sensor->getAddress(dev).c_str(), String(offset).c_str());
+                DEBUG_MSG_P(PSTR("Device %d/%s - Offset: %s\n"), dev, pzem004t_sensor->getAddress(dev).c_str(), String(offset).c_str());
             }
             DEBUG_MSG_P(PSTR("+OK\n"));
         }

code/espurna/sensors/PZEM004TSensor.h

@@ -3,6 +3,48 @@
 // Copyright (C) 2018 by Xose Pérez <xose dot perez at gmail dot com>
 // -----------------------------------------------------------------------------
 
+// Connection Diagram:
+// -------------------
+//
+// Needed when connecting multiple PZEM004T devices on the same UART
+// *You must set the PZEM004T device address prior using this configuration*
+//
+// +---------+
+// | ESPurna |                                             +VCC
+// |   Node  |                                               ^
+// | G  T  R |                                               |
+// +-+--+--+-+                                               R (10K)
+//   |  |  |                                                 |
+//   |  |  +-----------------+---------------+---------------+
+//   |  +-----------------+--|------------+--|------------+  |
+//   +-----------------+--|--|---------+--|--|---------+  |  |
+//                     |  |  |         |  |  |         |  |  |
+//                     |  |  V         |  |  V         |  |  V
+//                     |  |  -         |  |  -         |  |  -
+//                   +-+--+--+-+     +-+--+--+-+     +-+--+--+-+
+//                   | G  R  T |     | G  R  T |     | G  R  T |
+//                   |PZEM-004T|     |PZEM-004T|     |PZEM-004T|
+//                   |  Module |     |  Module |     |  Module |
+//                   +---------+     +---------+     +---------+
+//
+// Where:
+// ------
+//     G = GND
+//     R = ESPurna UART RX
+//     T = ESPurna UART TX
+//     V = Small Signal Schottky Diode, like BAT43,
+//         Cathode to PZEM TX, Anode to Espurna RX
+//     R = Resistor to VCC, 10K
+//
+// More Info:
+// ----------
+//     See ESPurna Wiki - https://github.com/xoseperez/espurna/wiki/Sensor-PZEM004T
+//
+// Reference:
+// ----------
+//     UART/TTL-Serial network with single master and multiple slaves:
+//     http://cool-emerald.blogspot.com/2009/10/multidrop-network-for-rs232.html
+
 #if SENSOR_SUPPORT && PZEM004T_SUPPORT
 
 #pragma once