Thursday, July 25, 2013

Propeller Simple Spin Board Part 4 & 5

Experiment 4: crisscross wiring
The Propeller Simple Spin Board will be expanded more in the future. Let's make some preliminary preparations for this and improve its reliability. While in it's RC speed state with RCFAST and RCSLOW, the circuit is already reliable and durable.
Experiment 5: decoupling


However, at higher clock speed, overclocking, with unusual loads or demands, electrical pressures and imbalances occur internally inside the chip, which is also effected with various operational configs. These conditions are not always for the better. However, it's possible to improve the operation of these circuits with external wiring and components.

Although it's a lot of technical mumble jumble jargon to describe it, basically the Propeller needs decoupling capacitors on each side of the dip chip, as close as possible to Propeller pins VSS and VDD, and a special added "criss-cross" wiring. Propeller experts say both the connective wiring and the capacitors (use a .1 uf value) belong to the chip and help to prevent blowing out the PLL circuits inside the chip.

The wiring connects one side of the chip to the other side. Ground VSS on one side (use a green or black wire) is connected to ground VSS on the other side, and power VDD (use a red wire) on one side is connected to power VDD on the other side. Use shortest wires that run directly over the top of the chip. This circuit will balance the chip's internal circuitry and help prevent a condition that could damage the chip. With these improvements installed, the Propeller chip is ready to run extremely fast and do much more than we ever expected. Stay tuned for more.

Another possible requirement involves using the addition of 10uf and 100uf capacitors for when the Propeller is expanded with additional demands. Due to limitations of breadboard pins nearest the chip, these capacitors may or may not connect at the power rails position.