[DStage]

Hello

I did mention my WBOOS board in a different part of the forum some years ago - viewtopic.php?t=3858. Since I recently made some changes I thought to share it with you here.

Let's start with a bit of history. WBOOS is another incarnation of the well known SLC Free project, and actually the first one! Yep, back when I first made it there was just the THT version of SLC Free 1 available and it had a strange thing in the SW - they either forgot or for some other reason did not add digital form to display AFR/Lambda, so I had to add it myself. It was added in a newer SW revision, but I did not notice it until I already did mine, so it differs i that regards, although I've checked and the values shown are pretty much the same

The arguably bigger changes I've made to the HW part, besides making it SMD (like SLC Free 2 these days). I never liked the simple reference voltage obtained by just dividing the 5V power with two resistors. So, WBOOS is using a proper, albeit not the newest band-gap reference voltage chip, the eternal TL431. Second change was a modification of the output signal PWM filters. I made them active and a 2nd order to get a bit less jerky signal.

That was all done years ago with v1.0. Now what has changed in v1.2.

Cosmetic changes to the HW:
- two resistors that were experimentally put on the connectors side are now on the component side (contrast potentiometer still left on connectors side for easier LCD adjustment)
- a few additional spare pins solder points added, for future purposes but also for what's coming in the SW part
- a bigger solder pad in case user wants to control the backlight

SW part where the bigger magic happens:
- just a reminder that some time ago also Lambda was added as an option to the LCD as years back I only gad AFR.
- the biggest change - it is now possible to connect a 7-segment LED display module based on TM1637 chip. It may be better visible in bright sunlight and it's not affected by low temperatures like the LCD can.
- when using LED display you can now also switch between AFR and Lambda by connecting a dedicated pin to +5V or GND.
- some people don't like the rapid refresh rate so I've highlighted the part of the program where you can change the LCD or LED display refreshed rate (in the precompiled HEX files on github I've added "slow" variants).

The LED display part can also be used in my Speeduino incarnation DSpeed or practically any other SLC Free variant that has some spare pins. Even those without an LCD build into ECUs (like in DSpeed) as programming pins can also be used for that

Here is the GutHub page where you can download the gerbers together with JLCPCB BOM (although they usually don't have CY8C24423 in stock, so this one has to be soldered separately). And of course the SW as well. I have also included a description of a few programming options for PSoC as recently I burned the PSoC MiniProg3 so had to search for alternatives.
https://github.com/DStageGarage/WBOOS/

[PSIG]

Confirming - does the refresh rate selection only affect the LCD, or also the log data?

[DStage]

If by the log data you're referring to the output linear analogue signal then the answer is no, it doesn't affect the rate this signal is refreshed.
The theoretical output signal refresh rate is set to around 50ms or 20 times per second. I say theoretical as I haven't actually checked how long all the other procedures take so it may be so that the refresh rate is irregular. But certainly it is refreshed more often than the display.

[DStage]

I've updated the SW yet again yesterday a bit. I figured out it is possible to display digital values of AFR and Lambda at the same time on LCD and they are accompanied by temperature as well. Making an option to switch between AFR and Lmabda as I did for LED proved difficult due to available flash memory space. In other words there would have to be compromises such as disabling NB output signal etc. But maybe having both at once suits everybody The precompiled file together with a slow variant is also available.

[PSIG]

Is it possible to have only AFR, or only Lambda, and still retain NBout? Else two versions for what the user needs? Only my own example, but I'd use only Lambda with NBout for most things I do, but options are always good.

[DStage]

Many combinations are possible of options available for enabling/disabling. NB is one of such options and it can pretty much stay on in every valid combination.
What I've mentioned on my previous post was just that during the code experiments I stumbled upon a problem requiring more space and NB would be a candidate to go but I really did not want to do it. Besides, how many people have to switch between AFR and Lambda especially when they can have both at the same time Just a note, the C compiler in PSoC designer is really strange

Here's the list of my precompiled proposals (table available on GitHub). They target the most that can be fit but of course you can always disable temperature and the other feature and only have one on the screen. All of the below have NB and WB output on.

[PedroV9]

Very cool update with the 7-segment display! Do you think you could add an input for brightness control? For example, when the headlights are turned on, the display brightness could dim.

I have a version with an 8x2 display.

[DStage]

Cool! I was thinking about the 8x2 myself heh.
I do have a solder pad on the connector side marked "BL" which can be used for backlight control. The idea is that you can modify R16 or remove it and connect that "BL" point to GND through external resistor to GND. Although now when I think about it it might be slightly inconvenient from the ground side. I think it could be also done with 12V with a proper resistor... I'll get back tou you

[PedroV9]

I believe that any N-channel MOSFET that tolerates more than 12V on the gate would solve the problem.

[DStage]

You're right of course and I had it in mind as an option but I'm thinking this might be possible without a transistor just with a cleaver choice of resistor Although, probably better to keep it less prone to local conditions and just go with NPN (might be easier in terms no need for specific model) or MOSFET-N.

Hmm, wait a minute... I think since we'd like it do go dimmer and react on +12V instead of ground that's not exactly it... need to think about t for a minute hehe (obviously it can be done with 2 transistors where one is a negator but I like the challenge of minimizing the components).

Edit: OK, here's what I come up with. The 3 "standard" diodes D1-3 are just to model the backlight LED voltage drop close enough. The 14V power source works as the voltage coming from the headlights switch. As you can see once you |"turn on the lights" the current of backlight LEDs drops from 9mA to 5mA (can be tweaked of course). Don't know, maybe I'm overthibking it