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Programmable Hardware Manual (PHM)
© Tibbo Technology Inc.
Combine this Tibbit with
(DB9M connector). It's
not common but possible to use the latter for wiring into the PWM outputs. The
Tibbit
(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 #16 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 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 access and set the PWM channels.
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 PWM setup (and PIC
behavior) without making any changes to the PIC firmware.
The GRA firmware can be updated or replaced using the
pic_firmware_upgrade
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
7.2.9.28
#17, M1S: Three PWMs With Power Outputs
Function:
Three PWMs with power outputs (the power must be supplied externally)
Category:
Output module
Special needs:
---
Power requirements:
5V/20mA
Mates with:
See also: