An Evaluation System for the TAOS Light-to-Frequency Converters
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Using the enclosed USB cable, plug the mini-B connector into the EVM module. Using the other end
of the cable, plug the USB A-connector into a USB port on the computer. A Wizard should appear
instructing the user to load a USB driver. See the "Light-to-Frequency EVM Quick Installation" for
instructions on loading the USB driver.
See Appendix for schematic diagrams of the LTF EVM motherboard and daughterboards.
Motherboard
The Light-to-Frequency Converter EVM motherboard consists primarily of an integrated BASIC Stamp
BS2pe microcontroller, two Atmel ATTiny13 microcontrollers used as coprocessors, and a USB
interface. Two sockets, referred to as socket A (J4) and socket B (J7) (see Figure 1) accept any of the
six sensor daughterboards. There is a coprocessor associated with each daughterboard, and these are
labeled “A” and “B” on the motherboard. Frequency measurements, period measurements and PWM
control of the daugherboard LEDs are performed by either the BASIC Stamp or the coprocessors
under BASIC Stamp control. The EVM is shipped with an application programmed into the BASIC
Stamp which controls the communication between the BASIC Stamp, the sensor coprocessors, and the
host PC software application.
The EVM daughterboards are hot-pluggable, that is, they may be installed and removed while the EVM
and host application is running. The host application will recognize the installed daughterboard(s) and
invoke the appropriate daughterboard window(s).
Daughterboards
Six daughterboards are included with the Light-to-Frequency Converter EVM supporting the evaluation
of the following devices: TSL230RD, TSL235R, TSL237S, TSL237T, TSL245R, and TSL238D. Some of
the daughterboards contain LEDs in either transmissive or reflective configurations. The
daughterboard configurations are summarized below in Table 1.
Figure 1 - EVM Motherboard