Brewing, Jeep Radio, MacroFab, MEP, nuclear battery, Podcast, pre-compliance, TDA7340S, Tektronix, Tritium, USB cable fail

MEP EP#44: Drive By DNA Destruction

Download: MP3
RSS Feed: Link

Runtime: (38:58)

Parker Dillmann
Stephen Kraig


Podcast Notes

  • Popping in last weeks audio was probably due to a cheap USB cable. Stephen and Parker recorded last week on a laptop with a USB powered mic preamp that has less then stellar power filtering and performance.
  • Stephen is continuing work on his automatic brewing rig. Has a motorized ball valve to control the flow rate for proper mashing and cooling rates.
  • Parker found the correct IC that is inside the Jeep radio. Part number TDA7340S. It is a 100% direct match to the pinout of the IC inside the radio. He found it by looking at ST’s catalog of Audio and Radio ICs from that time period.
  • To switch Audio sources to an external source, Parker is going to hack into the TDA7340’s external effects loop. See Figure 1. The signal will probably have a DC offset since the IC is on a single power rail of ~9.4V. DC offset should be around 4.5V. The Bluetooth adapter will need to have a DC offset to match. ICs to switch the audio signals will either be a NJM2520D or a MAX4544CPA+.
  • Shout out to Pat Hensley from Tektronix. Came by the shop earlier this week to get a tour of the fab and show off some Tektronix goodies. Got to play with a Tektronix RSA306B USB Spectrum Analyzer. Which was really awesome. Real time over USB. Interface is scriptable with Python. Will be looking at getting one for pre-compliance testing.
  • Attacking air gapped computers using the cooling fans. Basically a piece of malware tweaks the PWM on the fans inside the computer to transmit data audibly.
  • Make your own nuclear battery. Using Tritium keychains and some solar cells to produce power. The battery produces 1.6 volts at 800 nano amps or 1.23 microwatts.

Figure 1: Block Diagram of the TDA7340S and where Parker is going to inject the Bluetooth signal.
Figure 1: Block Diagram of the TDA7340S and where Parker is going to inject the Bluetooth signal.

Special thanks to whixr over at Tymkrs for the intro and outro!