18
Embedded Modules
© Tibbo Technology Inc.
4.1.1.5
Analog-to-digital Converter (ADC)
The EM2000 features a four-channel analog-to-digital converter (ADC). The ADC's
hardware resolution is 12 bits, while its effective resolution is about 7 bits. This
reduction in resolution is caused by the internal noise of the EM2000. Even with this
low resolution, the ADC module is useful for a wide variety of measurements.
The input voltage range of ADC inputs is from 0 to VCC (3.3V nominal). The ADC will
measure 0 when an ADC's input is at 0V, and 4095 when an input is at VCC.
Your Tibbo BASIC/C application can access the ADC module through the ADC (adc.)
object, which is documented in the TIDE, TiOS, Tibbo BASIC, and Tibbo C Manual.
4.1.1.6
I2C/SPI Support (SSI Channels)
Tibbo OS (TiOS) running on the EM2000 offers four "soft" synchronous serial ports
that can be used for I2C and SPI communications, with the EM2000 acting as the
master. All four SPI modes are supported.
Because the SSI channels are implemented entirely in software, any combination of
GPIO lines can be selected to serve as interface lines of an SSI channel. This is
facilitated by several I/O mapping properties offered by the ssi. object.
For more information see the documentation for the ssi. object found inside the
TIDE, TiOS, Tibbo BASIC, and Tibbo C Manual.
4.1.1.7
Square Wave Generator
The square wave generator can produce a square wave output on pin GPIO45/CO of
the EM2000. This output is primarily intended for generating audio signals using
buzzer and is covered in the beep (beep.) object — see the TIDE, TiOS, Tibbo
BASIC, and Tibbo C Manual.