Add additional Pylontech CAN protocol fields

[ranma]

I noticed that these are missing while looking at dissassembly of the Pytes implementation of the protocol. I also found Pylontech sample CAN messages which match the Pytes implementation [1]:

CAN ID – followed by 2 to 8 bytes of data:
0x351 – 14 02 74 0E 74 0E CC 01 – Battery voltage + current limits
                          ^^^^^ discharge cutoff voltage 46.0V
0x355 – 1A 00 64 00 – State of Health (SOH) / State of Charge (SOC)
0x356 – 02 13 00 00 4A 01 – Voltage / Current / Temp
0x359 – 00 00 00 00 0A 50 4E – Protection & Alarm flags
                       ^^^^^ always 0x50 0x59 in Pytes implementation
                    ^^ module count (matches the blog article image)
0x35C – C0 00 – Battery charge request flags
        ^^ two possible additional flags (bit 3 and bit 4)
0x35E – 50 59 4C 4F 4E 20 20 20 – Manufacturer name (“PYLON “)
        ^^^^^^^^^^^^^^ Note: Pytes sends a 5-byte message "PYTES" instead
                       padding with spaces

The extra charge request flag is "bit4: SOC low" (Seems to be SoC < 10% threshold for Pytes), I haven't bothered adding that as it provides little value.

[1] https://www.setfirelabs.com/green-energy/pylontech-can-reading-can-replication

[ranma]

[ranma]

int can_msg_pylontech_FUN_0802a2c8
              (int param_1,undefined4 param_2,undefined4 param_3,undefined4 param_4)

{
  struct can_battery_state_1 *batteryState;
  int stateOfHealth;
  uint batTemp;
  int tmp;
  int stateOfCharge;
  uint batVolt;
  uint batCurrent;
  byte *pbVar1;
  uint alarms0;
  int iVar2;
  uint alarms1;
  int numModules;
  byte bVar3;
  
  iVar2 = 0;
  batteryState = can_get_ptr_to_battery_state_struct_at_20000194_FUN_080087ec();
  pbVar1 = *(byte **)(param_1 + 0x20);
  alarms0 = batteryState->field12_0x30_alarms0;
  alarms1 = batteryState->field13_0x34_alarms1;
  numModules = batteryState->field2_num_modules;
  switch(param_2) {
  case 0:
                    /* msg 0x359 */
    bVar3 = 0;
    if ((alarms1 & 1 | alarms0 & 1) != 0) {
      bVar3 = 2;
    }
    if (((int)(alarms1 << 0x1b) < 0) || ((int)(alarms0 << 0x1b) < 0)) {
      bVar3 = bVar3 | 4;
    }
    if (((int)(alarms1 << 0x17) < 0) || ((int)(alarms0 << 0x17) < 0)) {
      bVar3 = bVar3 | 8;
    }
    if (((int)(alarms1 << 0x13) < 0) || ((int)(alarms0 << 0x13) < 0)) {
      bVar3 = bVar3 | 0x10;
    }
    if ((alarms0 & 0x60000) != 0) {
      bVar3 = bVar3 | 0x80;
    }
    *pbVar1 = bVar3;
    bVar3 = (alarms0 & 0x180000) != 0;
    if ((int)(alarms0 << 3) < 0) {
      bVar3 = bVar3 | 8;
    }
    pbVar1[1] = bVar3;
    bVar3 = 0;
    if (((int)(alarms1 << 0x1e) < 0) || ((int)(alarms0 << 0x1e) < 0)) {
      bVar3 = 2;
    }
    if (((int)(alarms1 << 0x1c) < 0) || ((int)(alarms0 << 0x1c) < 0)) {
      bVar3 = bVar3 | 4;
    }
    if (((int)(alarms1 << 0x16) < 0) || ((int)(alarms0 << 0x16) < 0)) {
      bVar3 = bVar3 | 8;
    }
    if (((int)(alarms1 << 0x14) < 0) || ((int)(alarms0 << 0x14) < 0)) {
      bVar3 = bVar3 | 0x10;
    }
    if ((int)(alarms0 << 10) < 0) {
      bVar3 = bVar3 | 0x80;
    }
    pbVar1[2] = bVar3;
    if ((int)(alarms0 << 9) < 0) {
      bVar3 = bVar3 | 1;
    }
    if ((int)(batteryState->field14_alarms2 << 0x16) < 0) {
      bVar3 = bVar3 | 8;
    }
    pbVar1[3] = bVar3;
    pbVar1[4] = (byte)numModules;
    pbVar1[5] = 0x50;
    pbVar1[6] = 0x59;
    iVar2 = 7;
    break;
  case 1:
                    /* msg 0x351 */
    alarms0 = (uint)batteryState->field55_charge_end_mV / 100;
    *pbVar1 = (byte)alarms0;
    pbVar1[1] = (byte)(alarms0 >> 8);
    alarms0 = (uint)batteryState->field53_charge_mA / 100;
    pbVar1[2] = (byte)alarms0;
    pbVar1[3] = (byte)(alarms0 >> 8);
    alarms0 = (uint)batteryState->field54_discharge_mA / 100;
    pbVar1[4] = (byte)alarms0;
    pbVar1[5] = (byte)(alarms0 >> 8);
    alarms0 = (uint)batteryState->field56_discharge_end_mV / 100;
    pbVar1[6] = (byte)alarms0;
    pbVar1[7] = (byte)(alarms0 >> 8);
    iVar2 = 8;
    break;
  case 2:
                    /* msg 0x355 */
    stateOfCharge = batteryState->field10_state_of_charge;
    *pbVar1 = (byte)stateOfCharge;
    pbVar1[1] = (byte)((uint)stateOfCharge >> 8);
    stateOfHealth = batteryState->field11_state_of_health;
    pbVar1[2] = (byte)stateOfHealth;
    pbVar1[3] = (byte)((uint)stateOfHealth >> 8);
    iVar2 = 4;
    break;
  case 3:
                    /* msg 0x356 */
    batVolt = (uint)batteryState->field29_battery_voltage_precision5 / 10;
    *pbVar1 = (byte)batVolt;
    pbVar1[1] = (byte)(batVolt >> 8);
    batCurrent = (uint)batteryState->field30_battery_current_precision6 / 100;
    pbVar1[2] = (byte)batCurrent;
    pbVar1[3] = (byte)(batCurrent >> 8);
    batTemp = (uint)batteryState->field41_battery_temperature_precision3 / 100;
    pbVar1[4] = (byte)batTemp;
    pbVar1[5] = (byte)(batTemp >> 8);
    iVar2 = 6;
    break;
  case 4:
                    /* msg 0x35c */
    bVar3 = 0;
    if (batteryState->field44_flag_charge_enabled != 0) {
      bVar3 = 0x80;
    }
    if (batteryState->field45_flag_discharge_enabled != 0) {
      bVar3 = bVar3 | 0x40;
    }
    if (batteryState->field49_flag_charge_immediately != 0) {
      bVar3 = bVar3 | 0x20;
    }
    if (batteryState->field50_flag_soc_below_10percent != 0) {
      bVar3 = bVar3 | 0x10;
    }
    if (batteryState->field51_flag_0xcc_maybe_soc_above_x_threshold != 0) {
      bVar3 = bVar3 | 8;
    }
    *pbVar1 = bVar3;
    pbVar1[1] = 0;
    iVar2 = 2;
    break;
  case 5:
                    /* msg 0x35e */
    for (tmp = 0; tmp < 5; tmp = tmp + 1) {
      *pbVar1 = s__PYTES_0802a4db[tmp + 1];
      pbVar1 = pbVar1 + 1;
    }
    iVar2 = 5;
  }
  return iVar2;
}

[ranma]

Liveview test using replayed CAN packets:

[ranma]

CAN message simulator (connect Pi GPIO 10 (MOSI) to ESP32 CAN rx input):

#!/usr/bin/env python3

import struct
import time
import pigpio


pi = pigpio.pi()
spi = pi.spi_open(0, 500000, 0)


def addbits(l: bytearray, v: int, n: int):
  for i in range(n):
    mask = 1 << (n - i - 1)
    if (v & mask):
      l.append(1)
    else:
      l.append(0)


def can_crc15(bits: bytearray) -> int:
  crc = 0
  for bit in bits:
    crcout = crc >> 14
    crc = (crc << 1) & 0x7fff
    if bit ^ crcout:
      crc ^= 0x4599
  return crc


def can_stuff(bits: bytearray) -> bytearray:
  stuffed = bytearray()
  ones = 0
  zeroes = 0
  for bit in bits:
    stuffed.append(bit)
    if bit:
      ones += 1
      zeroes = 0
    else:
      zeroes += 1
      ones = 0
    if ones >= 5:
      stuffed.append(0)
      ones = 0
      zeroes = 1
    elif zeroes >= 5:
      stuffed.append(1)
      zeroes = 0
      ones = 1
  return stuffed


def can_msg(msg: int, payload: bytes) -> bytearray:
  if msg >= 0x800:
    raise ValueError('msg id out of range 0x000:0x7ff')
  if len(payload) > 8:
    raise ValueError('payload len out of range 0:7')

  leader = (msg << 7) | len(payload)
  acked_trailer = 0x2ff

  bits = bytearray()
  addbits(bits, leader, 19)
  for b in payload:
    addbits(bits, b, 8)

  crc = can_crc15(bits)
  addbits(bits, crc, 15)
  stuffed = can_stuff(bits)

  addbits(stuffed, acked_trailer, 10)
  return stuffed


def make_bytes(bits: bytearray) -> bytearray:
  x = 0
  i = 0
  data = bytearray()

  def add_bit(bit):
    nonlocal x, i
    x = (x << 1) & 0xff
    x |= bool(bit)
    i += 1
    if i >= 8:
      i = 0
      data.append(x)

  for bit in bits:
    add_bit(bit)

  # pad with ones
  while i > 0:
    add_bit(1)

  return data


def send_msg(msg: int, payload: bytes):
  bits = can_msg(msg, payload)
  data = make_bytes(bits)
  # RPI MOSI line idles at zero in between transactions, add extra padding.
  pad1 = 16 * b'\xff'
  pad2 = 8 * b'\xff'
  pi.spi_write(spi, pad1 + data + pad2)



def send_pylontech_msgs():
  send_msg(0x351, b'\x14\x02\x74\x0e\x74\x0e\xcc\x01') 
  send_msg(0x355, b'\x1a\x00\x64\x00') 
  send_msg(0x356, b'\x02\x13\x00\x00\x4a\x01') 
  send_msg(0x359, b'\x00\x00\x00\x00\x0a\x50\x4e') 
  send_msg(0x35c, b'\xc0\x00') 
  send_msg(0x35e, b'PYLON   ') 


while True:
  send_pylontech_msgs()
  time.sleep(0.1)

[schlimmchen]

The new data points are interpreted and added to the live view, but please also publish them to the MQTT broker and add them to HASS auto-discovery.

[AndreasBoehm]

@DerHavey1994 @Snusme83
Habt ihr Zeit und Lust zu probieren ob diese Änderung die zwei neuen Felder Entladespannungs Limit und Modul Anzahl für eure Pylontech Batterie korrekt anzeigt?

Die entsprechenden builds findet ihr hier: https://github.com/helgeerbe/OpenDTU-OnBattery/actions/runs/10709343648?pr=1213

Danke vorab.

[DerHavey1994]

@AndreasBoehm läuft!

[AndreasBoehm]

Danke @DerHavey1994 fürs testen!

Great job @ranma!
Checking the actual code that runs on the batteries was an awesome idea.

[Snusme83]

@DerHavey1994 @Snusme83 Habt ihr Zeit und Lust zu probieren ob diese Änderung die zwei neuen Felder Entladespannungs Limit und Modul Anzahl für eure Pylontech Batterie korrekt anzeigt?

Die entsprechenden builds findet ihr hier: https://github.com/helgeerbe/OpenDTU-OnBattery/actions/runs/10709343648?pr=1213

Danke vorab.

Servus, soll ich noch testen? Kann ich das hier:
machen oder muss da wieder neu geflasht werden?

[AndreasBoehm]

@Snusme83 Genau da wo du gerade bist kannst du das verlinkte build als update hochladen.

[Snusme83]

Schaut gut aus. Hab zwei US3000C!

Blöde Frage: Könnte ich auf diese Art und Weise auch wieder auf das Release 2024.08.18 zurückgehen?🤔

[schlimmchen]

Blöde Frage: Könnte ich auf diese Art und Weise auch wieder auf das Release 2024.08.18 zurückgehen?🤔

@Snusme83 Ja.

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new discussion or issue for related concerns.