|Designing Your Own Platform Modules|
The Gadget Gangster Platform is designed to be easily expandable with the modules we've designed and with modules that you design. Below are specs and templates for common PCB Design applications.
If you've designed a module and want to share it, let us know — Just shoot us an email (firstname.lastname@example.org) - we can help you promote it or sell it for you.
Platform Modules feature dual connector rows for all pins, and each column should be interconnected. This is because the Platform Module underneath may have sockets on the outer row OR inner row.
We recommend that Platform Modules include all 40 connectors so that other modules can stack on top or below.
Propeller Platform kits use an ON MC33269T-5.0G LDO for 5v regulation @ 800mA (datasheet) and an ST LD1117V33 LDO Voltage Regulator for 3.3v regulation @ 800mA (datasheet) Both have a dropout of about 1V. Surface Mount Propeller and PICaxe Platforms use an ultra LDO, the ST LD29150DT33R (datasheet) and LD29150DT50R (datasheet). SMT regulators have a dropout of 0.1V @ 100mA, up to 0.5V @ 1.5A. All modules are rated at 12VDC max and use 2.1mm barrel jack power connectors.
The power switch on the Propeller Platform controls the flow of current through the power jack, but NOT Vin. If your Platform Module provides power through Vin, the power switch on the Propeller Platform will not turn it off, so you may want to include a power switch on your module.
Modules that provide power must provide power to both sets of power connectors. Modules that receive power can expect it at either set of power connectors.
We have suggested footprints for Platform Modules, but there are no requirements other than the positioning of pin headers. Stackable modules are limited to .310" height using 3M 2340-6211TG headers. Platform Modules that exceed that height are acceptable, but it should be noted that they are only suitable at the ends of a stack.
There are currently 2 Platform Module footprints:
No logic voltage level is specified. The Propeller Platform operates at CMOS (3.3v) logic voltage levels and is not 5V tolerant. Series resistors in the 1k-100k range are suggested on input pins interfacing with 5V logic voltage levels. PICaxe Platforms operate at 5v logic levels.
PULLUPS & PINS
The Propeller Platform kit includes one 10k? pullup on P29 (SDA) and space for a 1/4W pullup on P28 (SCL). SMT Propeller Platforms have 10k pullups on P0..P3, P29 (SDA) and P28 (SCL). All other pins are floating. Pullups on P0..P3 are for the onboard microSD card slot. Modules that require a pullup on SCL should include an extra 1/4W 10k? resistor in packaging for kit users. The Propeller Platform USB also has a TX / RX connection to an FTDI FT232R USB interface IC on P31 & P30.
These specifications & templates are made available under the terms of the MIT License. Do not include Gadget Gangster Trade Dress or logos on your design without our permission, but you are free to describe your product as "For the Propeller Platform", "For the Gadget Gangster Platform", "Propeller Platform Compatible", or "Gadget Gangster Platform Compatible".
H/T to Tim Swieter, E.I., of Brilldea for providing feedback on these specifications and donating Eagle templates. Thanks Tim!!!