Weekly Report February 23 2014

Since the RN42HCI does not support SSP (see previous weekly report post), I’ve switched to using a USB Bluetooth dongle to perform the spoof. This will allow me to get a huge data rate improvement, but at the cost of an USB port. I’ve made massive improvements to the USB host code, and my Total Phase Beagle USB 12 Analyzer really proved itself by telling me exactly how many tokens were sent and how many NAKs were received, which allowed me to gauge my maximum sample rate, and see noticeable differences when I make code changes.

But the bad news is that I can only see these tokens and NAK events as “collapsed records”, which means I can see that in the span of 2 seconds, I have gotten X amount of NAK from device A, Y amount from device B. But I can’t see if I get them in the order A B A B or A A B A A B. I’ve contacted Total Phase support about this, and it turns out that their more expensive analyzers support “packet view”. I asked if this was a hardware limitation, they stated that it was not, and I can capture the packets myself if I use their API that they provide. I asked them to update their software to add the support for my model, and they said they’ll pass on the request to their engineers and they’ll consider it.

Progress on the DualShock 4 spoof is great. I managed to get a reliable connection between the DualShock and my UsbXlater circuit via Bluetooth, and my UsbXlater circuit to the PlayStation via Bluetooth. I have a basic man-in-the-middle Bluetooth proxy working completely. The only problem now seems like the PlayStation doesn’t want to take the input yet, although I can see the data being passed, the PlayStation does not respond. The bigger issue is that the data being passed is coming so fast that my monstrous STM32F405RG chip is actually running out of RAM, I need to figure out whether or not this is indeed a performance issue or maybe I’m stupid and caused a memory leak.

Here I have my debug output a millisecond timestamp with the amount of RAM left, then it crashes

8000 FreeRAM 98132
10000 FreeRAM 88364
12000 FreeRAM 80868
14000 FreeRAM 72460
16000 FreeRAM 63092
18000 FreeRAM 53836
20000 FreeRAM 46428
22000 FreeRAM 37364
24000 FreeRAM 27756
26000 FreeRAM 17788
28000 FreeRAM 10068
30000 FreeRAM 716

Exception Handler, source: 1
r0: 0xF0127C08, r1: 0x2000293C, r2: 0x0000000A, r3: 0x0000000A, r12: 0x000002FF
LR: 0x00000000, PC: 0x20002948, PSR: 0xA1000200,

Neat… I’ve worked all weekend on this and got this far, I’m going to take a break and work on something else now. But my next goal is to figure out if I am freeing memory correctly, then maybe improve USB performance even more, and then implement flow control. Once the system doesn’t crash, I can focus on why the PlayStation doesn’t respond.

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