340
Tibbo Project System (TPS)
© Tibbo Technology Inc.
(four terminal blocks) can also be used but you will have to steal the ground
elsewhere, as #21 doesn't have its own ground line and the PWM Tibbit outputs
voltages with respect to the system ground.
LEDs
There are two red, one yellow, and one green LED. The first red LED is connected to
the SCL line of the I2C interface, the second one -- to the -RST line of the PIC
micro. The yellow LED is connected to the SDA line of the I2C interface. The green
LED is on the -INT line.
PIC micro and GRA firmware
Tibbit #31 ships with the GRA (
general register access
) firmware, which allows you
to access internal PIC registers and memory through the I2C interface. The firmware
implements a very simple communications protocol which essentially consists of two
important commands --
address read
and
address write
. These two commands are
used to write to and read from the PIC's internal RAM and registers. This facilitates
a simple and versatile access to all microcontroller resources. The available Tibbo
BASIC library sits on top of the GRA firmware and uses the communications protocol
to control the micro.
Since the GRA firmware does not do anything intelligent and all the setup work is
essentially scripted in Tibbo BASIC, it is possible to modify the PIC behavior without
making any changes to its firmware.
The GRA firmware can be updated or replaced using the
update_pic_firmware
Tibbo
BASIC project (see below). You can, therefore, create and run PIC applications that
go far beyond providing simple register and memory access.
Sample project
The use of this Tibbit is illustrated by a Tibbo BASIC test project. Yo can find it
here:
https://github.com/tibbotech/CA-Test-Tibbits-16-17-31
7.2.9.42
#35, C1: Barometric Pressure Sensor
Function:
Barometric pressure sensor
Special needs:
Tibbit
Power requirements:
5V/2mA
See also:
,