The PKS (Propeller Keychain System)
We've replaced the circuit board of the Coby 151 digital photo album
with a custom Prop board!
Using the original LCD, 8Mbit Flash memory chip, and LiPo
battery pack.
Packed with additional features:
3-axis accelerometer
Real time clock
buzzer
battery monitor circuit
Prop Plug replacement mode: Use the PKS like a Prop Plug
to program other Props!
Can optionally replace flash chip with 32Mbit version.
Software
Software is in development, but many basic test codes are already
available
These test codes are all based on a TV-like driver. This
driver acts pretty much the same as the original Parallax driver for TV,
but outputs to the PKS LCD screen.
Note: If you have a TFT screen, you'll need to make a small
change to the code to select the other driver as noted in the code
comments.
PKS Graphics Demo : A lot like the Parallax Graphics Demo
for TV, only smaller
PKS Accelerometer Test
: Test the onboard 3-axis mems
accelerometer
PKS Buzzer Test : Test the onboard buzzer (/speaker?)
PKS Flash Test : Test the onboard 8Mbit Flash memory chip
PKS RTC Test : Test the onboard DS1399 real time clock
chip
PKS Battery Monitor Test : Test the onboard battery
voltage monitor circuit
Circuit board pictures
Top:
Note: The battery voltage monitor circuit was an
afterthought, which is why it needs the jumper wire.
Bottom:
Note: The series 24 Ohm resistor for the buzzer is
an afterthought, which is why the buzzer is rotated.
Schematic
Note: There is an error in the schematic concerning how the
reset line is connected to the 4-pin PropPlug port. The reset pin
at the 4-pin port is actually connected to the junction of the 100-Ohm
resistor and the collector of the NPN resistor.
(click for full size)
(click for full size)