Decoding Engine Discrete Status 1 & 2

[AhtiKArjalainen]

I have 2 esp32, sender and receiver, + Veratron BT receiver on my test network.
Got everything else working on PGN127489 except decoding the error bits (Engine Discrete Status 1 & 2)
Sending is ok, because my Veratron shows them correctly on my phone, but can not decode the on my own esp32 receiver.
How to do it correctly ?
Long time , no coding , solution is simple i know it, just don't get it. Unable to find examples anywhere.

[ttlappalainen]

Bist are as single bit in Status1 and Status2 paramaters in order decribed in N2kMessges.h SetN2kPGN127489 documentation. 16 first bits are in Status1 and 8 bits on Status2.

[AhtiKArjalainen]

Even trying a single bitRead(Status1,x) results compilation error.
I'am missing something, just can't figure out what..
Know my sender is sending them correctly because Veratron is receiving them ok.

[svdrummer]

bitRead(Status1,x) Have you defined these somewhere. A code segment. As you have only been on Github a few days, normally people need more information than "you get and error"
Copy and paste the error, so people can determine what the error type is.

[AhtiKArjalainen]

void HandlePGN127489(const tN2kMsg &N2kMsg) {
unsigned char SID;
tN2kEngineDiscreteStatus1 Status1;
tN2kEngineDiscreteStatus2 Status2;

if ( ParseN2kPGN127489(N2kMsg, SID, EngineOilPress, EngineOilTemp ,EngineCoolantTemp,AltenatorVoltage,FuelRate,EngineHours,EngineCoolantPress,EngineFuelPress,EngineLoad,EngineTorque,Status1,Status2)) {

union tN2kDD206 {
uint16_t Status;
struct {
uint16_t CheckEngine:1;
uint16_t OverTemperature:1;
uint16_t LowOilPressure:1;
uint16_t LowOilLevel:1;
uint16_t LowFuelPressure:1;
uint16_t LowSystemVoltage:1;
uint16_t LowCoolantLevel:1;
uint16_t WaterFlow:1;
uint16_t WaterInFuel:1;
uint16_t ChargeIndicator:1;
uint16_t PreheatIndicator:1;
uint16_t HighBoostPressure:1;
uint16_t RevLimitExceeded:1;
uint16_t EGRSystem:1;
uint16_t ThrottlePositionSensor:1;
uint16_t EngineEmergencyStopMode:1;
} Bits;

      tN2kDD206(uint16_t _Status=0): Status(_Status) {};

};
}

So far compiles ok (Arduino IDE).

EngineOilPress, EngineOilTemp .....Are globals, i receive them ok...

No idea, is the flag set correct in union, or is my code even correct. If correct, how to proceed ? how to get values(correct bit that is high) out of union ?

[AhtiKArjalainen]

bitRead(Status1,x);

Results:
C:\Users\XXXX\Documents\Arduino\jc353_dsp001nmea\jc353_dsp001nmea.ino: In function 'void HandlePGN127489(const tN2kMsg&)':
C:\Users\XXXX\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.3.1\cores\esp32/Arduino.h:98:50: error: no match for 'operator>>' (operand types are 'tN2kEngineDiscreteStatus1' {aka 'tN2kDD206'} and 'int')
98 | #define bitRead(value, bit) (((value) >> (bit)) & 0x01)
| ~~~~~~~ ^~ ~~~~~
C:\Users\XXXX\Documents\Arduino\jc353_dsp001nmea\jc353_dsp001nmea.ino:364:3: note: in expansion of macro 'bitRead'
364 | bitRead(Status1,1);
| ^~~~~~~
exit status 1

Compilation error: exit status 1

Thats just a test, not ok , of course..

[ttlappalainen]

You can test it e.g.,, if ( Status1.CheckEngine ) {...}

[AhtiKArjalainen]

Compilation error: 'using tN2kEngineDiscreteStatus1 = union tN2kDD206' {aka 'union tN2kDD206'} has no member named 'CheckEngine'

Maybe i'am just C(pp) invalid (like 99.9% people are).
Will try again tomorrow when i'am sober.....

[svdrummer]

Seems like you are using an older esp32 hardware core or 3.3.1 Try 3.3.3 there have been breaking changes and libraries have been updates for other devices. Maybe when you are not under substance influence :) Most of us are Cpp valid.

[ttlappalainen]

My mistake if ( Status1.Bits.CheckEngine ) {...}

[AhtiKArjalainen]

if (Status1.Status !=0 ){}

That works enough for me, thank you.

but for future use, was it so that only one error flag can be high at a time ?

Sad that i could not find any info on the internet what PGN's Tohatsu supports. Honda has a nice list. Need to wait for next spring to get my hands on the engine.

Building up engine display using that with GPS module to get speed also displayed.
https://www.aliexpress.com/item/1005007772084275.html
Maybe put a water pressure sensor also into the motor (if there's space for it.)

[ttlappalainen]

No. Any flag combination is possible. You can test each flag as I mentioned before. You will find flag names from NMEA2000StdTypes.h tN2kDD206 and tN2kDD223