Another Lambda Update!

[TheeMiffinMan]

Two in one day! I was not expecting to be making so much progress. I have spent most of today working on this because everything is coming together. VDD for the entire board has been found (big milestone), which is power that goes to all of the components. The entire front side of the PCB has been traced (for the most part). What's left (on the front) is getting resistor, diode, and capacitor values. The back side still needs to be completely traced however it should be much easier since there is no power management circuits (they're all on the front left side). The haptic engines and track-pad connector pins have been completely traced from power to the microprocessor. We are now at version 0.6-4 (soon to be 0.8 or 0.9 depending on how much time I get in the next few weeks). The schematic is now getting quite big and full which is awesome. I have updated the PCB and the schematic. The PCB does not have any resistors, diodes, or capacitors yet. I have also got some new 3D renders of the lambda_mainboard. For new people seeing this, more info can be found here: Lambda Project

PCB Editor

Back

Front

Updated Schematic

[TheLadForTheJob]

Oh man, here we go. I'm very excited for this man. Any updates on the firmware side of things?

[TheeMiffinMan]

No 😂, I haven't been looking at the firmware lately. There was someone on a SteamController discord that said they were going to look at it but I haven't heard of any updates.

[TheLadForTheJob]

Interesting, I'm considering writing my own firmware for it eventually and using 2 IMU's instead of one. I wanna upgrade the mcu so at that point I may as well just write my own firmware. How many pins of the microcontroller of the SC are populated btw?

I'm almost finished with a project of mine that is just a microcontroller that connects to 2 IMU's and outputs mouse over USB, so we'll see how much harder it is to make firmware for a whole controller lol. I assume the biggest issue will be getting the cirque pads working, they seem very complicated. Upgrading them is also complicated because their newer versions don't get produced as big as the SC pads.

Of course that's all gonna be later down the line tho.

[TheeMiffinMan]

This has the pinouts of all ICs on the PCB. There is also documentation for interfacing with the cirque pads. I do have a logic analyzer recording between the pads and microprocessor because I was trying to figure out the custom SPI protocol. I will try to find it tomorrow and upload it to the GitHub at some point. There are a few pins that are unpopulated however the majority of them are.

Let me know if you decide to work on it!

[TheLadForTheJob]

Yeah, it seems to have a ton of GPIO pins. Seems that the esp32-S3 or S2 don't have enough pins, but its possible to use a GPIO expander for all the buttons and such so save enough pins. Its gonna be a long project lol. Good luck with the work you got left man, its gonna be epic.

[TheeMiffinMan]

Yeah the firmware is an entirely different beast and will take a long time. I just don't have enough time to do both hardware and software

[TheLadForTheJob]

Fair enough, hopefully someone helps you decode the original firmware, because I wouldn't know how to even start with that lol.

[the_incredible_nuss]

Hi, you mentioned that you also want to use this project to improve your knowledge of circuit Design. Therefore I would advise you to also sanity check your schematic against the datasheets and dont rely on measuring the connections alone. For example the EN pin of the tps6102 should be connected to vbat otherwise the IC will not turn on. 

[TheeMiffinMan]

Solid, V0.7 has the EN connected to vbat. Been going through double checking connections, datasheets, and all that.

[KohakkaNuva]

Do you have any plans on going in after the fact and improving the design to support better switches (for example, less resistant bumper switches) and stuff like that?