To connect my Sandisolar inverter to Home Assistant, I needed some kind of adapter in between. I decided for ESP32C3 with Tasmota firmware. RS232 connection at RJ45 connector is the same like other Chinese converters.

• https://github.com/arendst/Tasmota
• Schaltplan

The following registers are read only holding registers for the most common values.

Tasmota Script.txt

; GPIO's auf NONE stellen!
 
>M 1
; Optimierte Abfrage der Live-Register deines SD-4862W-II-EU (9600 Baud, Slave 1)
+1,20,m,0,9600,PowMr,21,3,010300ca,010300cc,010300d0,010300d2,010300d4,010300d6,010300d8,010300da,010300f0,010300f2,010300f4,010300dc,010300de,010300e0,010300e2,010300e4,010300e6,010300e8

; Netz (Grid) - Block @i0 (00CA, 00CB, 00CC )
1,010304UUuuxxxx@i0:10,AC Voltage,V,AC_Voltage,1
1,010304xxxxUUuu@i0:100,AC Frequenz,Hz,AC_Freq,1
1,010304UUuuxxxx@i1:1,CC AC Leistung?,W,AC_power,0
1,010304xxxxUUuu@i1:10,CD Spannung OUT3,V,CD,1

; Batterie Strom - Block @i1 (00D0, signed ssSS)
1,010304SSssxxxx@i2:10,D0,A,Reg_D0,1
1,010304xxxxUUuu@i2:10,D1,W,Reg_D1,1

; Ausgang (Load) - Block @i2 & @i3 (00D2, 00D4, 00D5)
1,010304UUuuxxxx@i3:10,Spannung OUT1,V,Out_Voltage,1
1,010304xxxxUUuu@i3:10,D3,A,Reg_D3,1
1,010304UUuuxxxx@i4:100,Frequenz OUT1,Hz,Out_Freq,1
1,010304xxxxSSuu@i4:1,Leistung OUT1,W,Out_Power,0

; Ausgang Scheinleistung & Batterie - Block @i4 & @i5 (00D6, 00D7, 00D8)
1,010304UUuuxxxx@i5:1,Ausgang Scheinleistung,VA,Out_VA,0
1,010304xxxxUUuu@i5:10,Battery Voltage,V,Batt_Voltage,1
1,010304SSssxxxx@i6:10,Battery Current,A,Batt_Current,1

; Solar (PV) - Block @i6 (00DA & 00DB)
1,010304UUuuxxxx@i7:10,DA,V,REG_DA,1
1,010304xxxxUUuu@i7:10,PV Spannung,V,PV_Voltage,1

; Temperatur - Block @i7 (00F0)
1,010304UUuuxxxx@i8:10,Inverter Temperatur,°C,Inv_Temp,1
1,010304xxxxUUuu@i8:10,F1,W,Reg_F1,1
 
1,010304UUuuxxxx@i9:10,F2,V,Reg_F2,1
1,010304xxxxUUuu@i9:10,F3 Spannung?,V,RegF3,1
 
1,010304UUuuxxxx@i10:10,F4 Spannung OUT2,V,RegF4,1
1,010304xxxxUUuu@i10:10,F5,W,RegF5,1
 
1,010304UUuuxxxx@i11:10,DC,W,RegDC,1
1,010304xxxxUUuu@i11:10,DD,W,RegDD,1
 
1,010304UUuuxxxx@i12:10,DE,W,RegDE,1
1,010304xxxxUUuu@i12:1,DF PV Leistung,W,PV_Power,0
 
1,010304SSssxxxx@i13:1,E0 Battleistung,W,Batt_Power,0
1,010304xxxxUUuu@i13:10,E1,W,RegE1,1
 
1,010304UUuuxxxx@i14:10,E2,W,RegE2,1
1,010304xxxxUUuu@i14:10,E3,W,RegE3,1
 
1,010304UUuuxxxx@i15:10,E4,W,RegE4,1
1,010304xxxxUUuu@i15:10,E5,W,RegE5,1
 
1,010304UUuuxxxx@i16:10,E6,W,RegE6,1
1,010304xxxxUUuu@i16:10,E7,W,RegE7,1
 
1,010304SSssxxxx@i17:10,E8 Battery current,A,RegE8,1
1,010304xxxxUUuu@i17:10,E9,W,RegE9,1
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