[JHolland]

I didn't get to test it with an oscilloscope. I was just basing it off the megasquirt grounding scheme.

Well the MS scheme tallies with the Bosch recommendation. It may well cause issues - the application information for the CJ125 separates the power and signal ground, this was a change from the CJ110 application example where they were shown as common which did cause issues. The SPI interface was a further change to eliminate ground issues.

[Mappie]

Hi,

got a question about the PWM output pin Voltage of the bl49sp

i'd like to have a narrowband 0-1V output signal on this pin, so i can feed a OEM ecu with this signal.
how can i change this from the 0-5V signal to narrowband signal 0-1V ?

does it need adjustment on these values? :

/* Lambda Outputs are defined as follow:
*
* 0.5V = 0,68 Lambda = 10 AFR (Gasoline)
* 4,5V = 1,36 Lambda = 20 AFR (Gasoline)
*
* Internal Lambda is used in a range from 68..136
*
**/
#define LambdaToVoltage(a) ((a * 5882UL / 100UL) - 3500UL)
#define VoltageTo8BitDac(a) (a * 255UL / 5000UL)
#define VoltageTo12BitDac(a) (a * 4095UL / 5000UL)

/* Calculate millivolt from adc */
#define AdcToVoltage(a) (a * 5000UL / 1023UL)

I guess it should become something like ?:

0V = 0,68 Lambda = 10 AFR (Gasoline)
1V = 1,36 Lambda = 20 AFR (Gasoline)

im looking for hours... but unfortunately can't find my answer.

btw. im using it as standalone device, so i would like to have the 0-5V signal and one 0-1V narrowband signal to feed the OEM ecu.

can someone hep me in the right direction?
thanks.

[dener0987]

Guys taking a deeper look at the heater PID and the FastPid library used in this project. I noticed that the setpoint and feedback of the PID algorithm is defined by the step function. However, looking at where the step function is called and the values ​​entered into it seem to be wrong. What would In.UR be? This input is connected to a capacitor that is connected to gnd.

As can be seen here on schematic https://github.com/oelprinz-org/BL49SP/ ... matics.pdf

ADC6, which would be the input for the UR, is connected to a capacitor and GND. Is this right? What is the logic behind this?

[dener0987]

Guys. After some time studying the code I have a better idea of ​​how it works.
I noticed that the Abl.UROpt variable is calculated in the calibration phase by reading the UR output of the cj125, which appears to be the signal from the nernst cell. Well, would this variable be the target of the PID? Since this variable is the target of the PID, shouldn't it be in the setpoint of the step function? According to the FastPID library documentation, the first variable of the step function is the setpoint.

[PSIG]

Whatever notes are verified and correct would be AWESOME to include in the code as remarks for users to follow.

[dener0987]

Whatever notes are verified and correct would be AWESOME to include in the code as remarks for users to follow.

Yes, I posted it here so we can debate whether I'm correct or not. Maybe the code developer can tell us if I'm correct. What do you think my correction makes sense?

[Alfagta]

Guys. After some time studying the code I have a better idea of ​​how it works.
I noticed that the Abl.UROpt variable is calculated in the calibration phase by reading the UR output of the cj125, which appears to be the signal from the nernst cell. Well, would this variable be the target of the PID? Since this variable is the target of the PID, shouldn't it be in the setpoint of the step function? According to the FastPID library documentation, the first variable of the step function is the setpoint.

Hello,

that is done to change the „polarity“ of the pid controller.

And In.UR is correct