Wideband O2 Controller Project with EGT, A2D, DAQ, Diagnostic, Etc.

[wheming]

Or, use an old android phone as a nice screen and develop a simple app to uitilize and display those outputs.


Was your display about the size of a traveler window? Or maybe it is larger?

[Turbo SOB]

The processor I am using to handle the "instrument cluster" module has a USB function built-in. I am using a Renesas RX62N development board. The black box with the fancy chrome ring knobs is a tweaked version of my work project with another M16C chip. I'm only using it to develop the interface, as the only thing the box needs to do (at the moment) is receive CAN messages and display them. I already have a port of the code over to the RX board.

I'm still not 100% clear on what I'll use to replace the knobs. I have an idea, I'll float it soon. Stay tuned.....

I'll say this, though some may not agree with my reasoning, that I am doing this is to produce a display free of operating systems. The system will function on it's own without the interference of any computers (Windows, Android, whatever). Operating systems crash, need boot time, etc. I do plan on integrating some kind of external computer interface using that USB port, but only as an auxiliary data logger or secondary display. The primary function of the USB port will be to log data directly to a thumb drive, in CSV format or something like that. I would love to configure it to interface to MPScan, but that's still a bunch of steps too far ahead.

That said, I do have a YLCDRSKRX62NS kit that I plan on working with. It contains a 480x272 LCD with touchscreen, and operates directly on the RX62N with FreeOS. It's a little advanced, but I'm fairly certain I can use it to build a crash-free cluster module with minimal boot time.



The 12-button navigator window might be a tight squeeze for the 128x64 VFD (or equivalent LCD), but I'm sure it would look fine. The 90+ 2-button traveler window is pretty big, so I don't think that would be an issue.

[sdac guy]

VERY cool !!


Barry

[Reaper1]

This has "EPIC" written all over it!

[Turbo SOB]

I made a video demonstrating the CAN sleep and wake-up functionality.

http://youtu.be/uB1nIBNhgpE

[rusefi]

It took me a while to figure out how to work the CJ125. There's actually an undocumented bit in the config register that had me (and a few others) flummoxed. Needless to say, we figured it out. "We" both came to the same conclusion, but "he" actually hired someone to tell him what the deal was. Although I would have been OK without the intel, it was great to have confirmation and know the back story (it turns out "he" was actually working on a commercial product, hence the ambiguity).

Any chance you would elaborate on the undocumented bit?

I am working on a DIY open source ECU, we already have some functional hardware and software and some engines running, any chance you would be available to help us add CJ125 onto our board?

[Turbo SOB]

Sure. The more people using this chip the better.

It's been a while since I've worked on this. Having kids really changes ones priorities.

Essentially, when you fire up the CJ125 for the first time, if you read the INIT_REG1 before setting it, you should read back 0x89. This is the key. I discovered that if I didn't overwrite INIT_REG1 in the initialization process, it would work just fine. So, leave bits 3 and 7 high and it's happy. You can change bit 0 if you want, but I find that it works just fine in x17 mode all the time. I will play with this more in the future to see if I can improve precision.

Here's a snippet from my source code. It explains the first initialization register and the undocumented bits.

/**********************************************************************************
    INIT_REG1 - CJ125 Initialization Register 1
        00x000x0
        ||||||||---- VL - Pump Current Sense Amplifier - 0 = x8, 1 = x17
                            If VL is set to "0" the amplification of Ip is 8.
                            If VL is "1" the amplification is 17. The higher
                            amplification is needed for a better resolution
                            at Lambda > 1, amplification 8 for Lambda < 1.
                            Note: It seems to make no difference, always set to 1.
        |||||||----- Unused
        ||||||------ LA - Pump Current Sense Amplifier - 0 = measurement, 1 = calibration
                            If LA is "0" the measurement mode for Ip is active.
                            The current pump current is displayed on Ua. If LA is
                            set to "1" the calibration mode is active. The shown
                            voltage on Ua must been subtracted from the later measurement.
        |||||------- Undocumented Bit - Note: CJ125 only seems to work when set to 1.
        ||||-------- RA - Measurement Current for Ri - 0 = measurement, 1 = calibration
                            If RA is "0" the measurement mode for Ri is active and
                            the current resistance of the probe is "displayed" on Ur.
                            If RA is "1" the calibration mode is active. You get the
                            optimal voltage for the inner resistance of the probe on Ur.
        |||--------- Unused
        ||---------- PA - Pump Current Control - Set to 0 to be active
        |----------- ENABLE/HOLD - Must be set to 1 to enable
***********************************************************************************/

[Turbo SOB]

Here's these too. They're already well documented, but my comments may help.

/**********************************************************************************
    INIT_REG2 - CJ125 Initialization Register 1
        xxx00000
        ||||||||---- PR0 - Reference Pump Current (10 uA)
        |||||||----- PR1 - Reference Pump Current (20 uA)
        ||||||------ PR2 - Reference Pump Current (40 uA)
        |||||------- PR3 - Reference Pump Current (80 uA)
        ||||-------- ENSCUN - Enables diagnostics for pin UN of the CJ125
        |||--------- Unused
        ||---------- Unused
        |----------- Unused
***********************************************************************************/

/**********************************************************************************
    DIAG_REG - CJ125 Diagnostic Register Definition (Read Only)
        00000000
        ||||||||---- Sensor VM Diagnostic Bit 0
        |||||||----- Sensor VM Diagnostic Bit 1
        ||||||------ Sensor UN Diagnostic Bit 0
        |||||------- Sensor UN Diagnostic Bit 1
        ||||-------- Sensor IA/IP Diagnostic Bit 0
        |||--------- Sensor IA/IP Diagnostic Bit 1
                            00 = Short circuit to ground
                            01 = Low Battery
                            10 = Short circuit to Vbatt
                            11 = No Failure
        ||---------- Ext. Heater DIAHD Diagnostic Bit
        |----------- Ext. Heater DIAHG Diagnostic Bit
                            00 = Short circuit to ground
                            01 = Open Load
                            10 = Short circuit to Vbatt
                            11 = No Failure
***********************************************************************************/

[85glht]

Ok, so.... What did I just read?

[Turbo SOB]

Don't worry. Just smile and nod and look at the pretty blinking lights.

[Turbo SOB]

If you are WTFing right now..... That picture was from the TV show Fringe. The green, green, green, red blinking lights were used to hypnotize people for nefarious purposes.

Sorry, my sense of humor can be out there.

INIT_REG1, INIT_REG2 and DIAG_REG are register names for the CJ125 configuration registers. These are directly from the Bosch CJ125 spec sheet, which is readily googleable. These 3 registers are not defined very well on that spec sheet. Above, I line out exactly what each bit in the register bytes do.

[rusefi]

OMG, this is AMAZING info! Thank you. I hope to bother you in about 6 weeks once I get some boards to play with

[85glht]

So, I'm guessing you built a computer to read and run your car with a wideband o2 sensor? If so, genius. If not, what did I read again?