growattLink.c File Reference

Communication with a Growatt inverter. More...

#include "arch/config.h"
#include <stdint.h>
#include "mqttHome.h"
#include "growattHome.h"
#include "weUtil.h"
#include "weModbusBC.h"
#include "weStateM.h"
#include "weLockWatch.h"
#include "weShareMem.h"
#include <errno.h>
#include <sys/sem.h>
#include <getopt.h>
#include "weGPIOd.h"

Functions
int	main (int argc, char **argv)
	The program. More...
void	mqttClean ()
	End as MQTT client.
int	mqttInit ()
	Initialise as MQTT client. More...
void *	processIOthread (void *args)
	The task of controlling process IO. More...
void *	rs232ModThread (void *args)

Variables
char	clientId [38]
	MQTT client ID. More...
modBvals_t	modBvals
	modbus respectively process values
char const	prgNamPure []
	The pure program name. More...
char const	prgSVNdat []
	The complete SVN date string. More...
char const	prgSVNrev []
	The complete SVN revision string. More...
char	subTopStPlg01 [14]
	State sub topic of S20 plug Number 01 to 09. More...

Detailed Description

Communication with a Growatt inverter.

The program's main task is to communicate with (currently) one Growatt PV (photovoltaics) inverter via its RS232 Modbus interface. Data got on a regular basis from the input and holding registers are made available to other programs on the same Pi, like e.g. the GCI program growattRead.c, by shared memory. Locking and signalling for the shared memory is done by a semaphore set. This is the same approach as in hometersControl.c.

The most important panel/inverter values are signalled to programs on other Pis (hemetersControl) by MQTT. The MQTT message has the form: Up: 119.6V P: 65.0W L: 7.2W T: 26.5gdC Wd/t: 1.2 / 2316.2kWh featuring Panel DC voltage, line Power (to grid), inverter loss and temperature, day's and total work.

The program runs on a Raspberry with GUI-less (no graphics) Raspbian lite. GUI/HMI is featured as Web-Interface (Apache, C CGI) in the (W)LAN.

Copyright  (c)  2019 2025  Albrecht Weinert
weinert-automation.de      a-weinert.de
 
    /         /      /\
   /         /___   /  \      |
   \        /____\ /____\ |  _|__
    \  /\  / \    /      \|   |
     \/  \/   \__/        \__/|_                                 

Revision history

Rev. 76 26.02.2025
Rev. 213 13.08.2019 : new; derived from hometersControl.c
Rev. 216 31.08.2019 : first operable with Modbus outages (hopefuly)
Rev. 219 06.11.2019 : Growatt MQTT all important values in one message
Rev. 270 07.11.2024 : use old includes before meterpi crash ("BC")
Rev.  76 22.02.2025 : from pi to sweet

Communication

This program uses serial communication with a RS232 converter to handle the Growatt inverter's Modbus link.

MQTT protocol via Ethernet or WLAN is used to publish essential inverter values and data. The MQTT broker or host defaults to 192.168.178.87, the port is 1883.

HTTP is used for GUI (via Apache and program growatt.read). HTTPS is not used as all LAN communication is in guarded private home or laboratory networks.

Common memory is used to communicate with other programs. At present this is a a small CGI program handling the AJAX link to the Apache based Web interface.

A backlink via HTTP parameter and shared memory and/or MQTT to control the inverter (via holding registers) is not implemented but may be in the future.

GPIO usage

This communication program currently uses no GPIO pins but includes all libraries etc. to do so.
As Test it uses three pins as output assuming LEDs connected to defined in include/target_growPi.h as Hi=On

Pi 1  / Pi 3       Pin
GPIO17/ 17 : red    11
GPIO21/ 27 : green  13
GPIO26     : yellow 47 

Modbus usage

This program acts as client for one Growatt inverter 1500P "GEAD1018" with firmware G.2.0 and Modbus protocol version 3.01. It is a single line phase, single PV array and zero battery type.

Communication setting will be 'RTU / RS232 9600, none'.

Timing

The program has a cyclic process control (in SPS manner). We have

a) a 100 ms cycle for process control, process I/O, SFCs etc.
b) an 1s cycle for Modbus communication, timer handling and some SFCs 

Server functions

Shared memory and a set of three semaphores is provided to share current values with other (C) programs as well as (in future) for receiving command and status information. This interface is also used to provide web interfaces in a flexible way.

Client functions

The program acts as (see above) as Modbus client. And it acts as MQTT publisher currently using a mosquitto broker on another Raspberry in the same private (W)LAN.

Library usage

The program uses the standard libraries pthread, pigpiod_if2, modbus, shm, sem and mosquitto. The own libraries in weRasp/..c and include/..h, namely weModbus, weGPIOd, sysUtil, weShareMem, weCGIajax etc. are compiled and linked in.

cross-compile by:

make PROGRAM=growattLink TARGET=growPi clean all             

program respectively transfer to target machine by:

make PROGRAM=growattLink TARGET=growPi progapp 

Due to idiosyncrasies of newer windows versions the make file can't execute the command (as was done for may years and variants)

winscp.com /script=progTransWin /parameter us:pw growPi bin growattLink 

Instead it will be output and must be copied and executed by hand.

The building of this application is governed by the make include files makeProg_growattLink_settings.mk and makeTarg_growPi_ettings.mk. The latter will lead to including include/arch/target_growPi.h.

Function Documentation

mqttInit()

int mqttInit

(

)

Initialise as MQTT client.

On success only: subscribe, loop and publish.

Returns

0: success the common mosq is set and usable; else: errno

processIOthread()

void * processIOthread

(

void *

args

)

The task of controlling process IO.

Except for the Modbus communication, this thread controls all processIO: at present this is just three LEDs.

It is a 100 ms cycle thread.
The cyclic 100 ms task then distinguishes 10 steps within a second. This ten (0..9) steps serve for the synchronisation with the other thread and act as state machine framework.

rs232ModThread()

void * rs232ModThread

(

void *

args

)

out char formIfix[60] = // form P 2 l7 Wd 16 l4 T 27 l5 Up 40 l 6 0123456789x123456789v123456789t123456789q123456789c1 2 3 4 "P: 1299.4W, Wd: 12.4kWh, T: 29.7gdC, Up: 114.3V\0\0\0"; formFixed16(formIfix + 2, 7, // form P 2 l7 modBvals.imp0Regs.regs[12], 1); // lo line power / .1W formFixed16(formIfix + 16, 4, modBvals.imp0Regs.regs[27], 1); // lo work day / .1 kWh formFixed16(formIfix + 27, 5, modBvals.imp0Regs.regs[32], 1); // Temp / .grdC formFixed16(formIfix + 40, 6, modBvals.imp0Regs.regs[3], 1); // Upanel / .1V = out

main()

int main	(	int	argc,
		char **	argv
	)

The program.

run by: growattLink [options
For options see longOptions and :: optHlpTxt.

Parameters

argc	number of parameters + 1
argv	optional options

xxxxx for(;commonRun;) { // use main thread for async tasks like MQTT pthread_yield(); break; // no asyn tasks yet if (!commonRun) break; pthread_yield(); if (!commonRun) break; if (!commonRun) break; pthread_yield(); if (!commonRun) break; } // commonRun async tasks xxxx

Variable Documentation

prgNamPure

char const prgNamPure[]

The pure program name.

To be provided in the application's / program's source.

See also

progNam() progNamB()

prgSVNrev

char const prgSVNrev[]

The complete SVN revision string.

To be provided in the application's / program's source.

See also

progRev()

prgSVNdat

char const prgSVNdat[]

The complete SVN date string.

To be provided in the application's / program's source.

See also

progDat()

subTopStPlg01

char subTopStPlg01[14]

State sub topic of S20 plug Number 01 to 09.

It's preset as plug01/POWER for 01, but the digit at index [5] will be set before each use accordingly.

clientId

char clientId[38]

MQTT client ID.

default value: sweetHomeControl; length: 15; max. length: 36
May be changed before mqttInit().