G.9.8) TBOT

TBOT (Tim's Box Of Tricks) was created to assist in troubleshooting failures of sensors in modern vehicles. Specifically, it has three modes:

  • Create a 5 V square wave (1 Hz to 200 kHz)
  • Create a user-defined 5 V p-p wave
  • Record input signals.

Mode 1

Mode 2

In Mode 2 the internal counters of the Propeller micro-controller are used to perform simple digital-to-analogue conversion between 0V and +3.3V. The
output pin is connected to the ‘Mode 2’ socket via 1K. resistor.

The digital-to-analogue conversion is a simple 8-bit affair, giving 255 steps between 0 V and +3.3V. The shape of the curve is defined by the ‘CURVE.txt’
file on the SD card or, in the absence of the SD card, a 0 – 1.1V sine wave.

The CURVE.txt file is a list of fifty integers between 0 and 255 and can be edited by the excel file “CURVE GENERATOR.xls” on the SD card. This allows the importing, editing and export of curve files to meet specific requirements, e.g.

Mode 3

Mode 3 allows signals to be recorded to an SD card using a 12 bit ADC.