Author Topic: RFD22301 Breakout Using PLCC Sockets  (Read 927 times)

sn74ls14n

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RFD22301 Breakout Using PLCC Sockets
« on: March 30, 2016, 08:54:23 PM »


If you are prepared for a bit of fabrication effort, Programming and Full-Breakout shields for socketed connection of a RFD22301 module to the RFD22121 USB Shield can be made using PLCC sockets.  PLCC sockets match the 1.27mm (0.05”) RFD22301 pin pitch and are about the right size.  Use PLCC sockets which breakout the PLCC socket contacts to 2.54mm (0.1”) pitch through-hole pins on the underside of the socket (eg. Digikey or, in Australia, Jaycar).

Simplest is a Programming Shield using a PLC44 (44-pin) socket where pin contacts on only one side of the socket are required.  First cut a piece of stripboard leaving a 9 x 8 array of holes.  Solder 5-pin and 7-pin rows of (Arduino shield) stackable headers down opposite short sides of the stripboard to mate with the RFD22121 USB Shield.  Prise the plastic stackable header housing away from its pins, and cut the pins flush with the top of the board; leaving the male pin portion protruding from the underside of the board.  Mount the PLCC44 socket to the top of the board between the two rows of stackable header pins and solder in place.

Because PLCC socket contact breakout arrangements may vary, first determine how the PLCC socket contacts connect through to the pins on the underside of the socket.  Then solder links to the appropriate stackable header pin for making a connection to the RFD22121 USB Shield.  Five connections (GPIO0, GPIO1, RESET, +3V and GND) are required between the RFD22301 Module and the RFD22121 USB Shield as per the RFD22301 Programming Interface datasheet, page 12.  Note, in this picture one link is made using a solder bridge between neighbouring pins which lies below a wire link.

Note: When soldering links to the stackable header pins, temporarily support the pin to be soldered using a 2-pin stackable header socket to a neighbouring pin as solder is the only thing holding the pin in position following the removal of the plastic stackable header housing.

Cut a 17mm x 17mm square from 1mm thick plastic and insert in the base of the socket to raise the RFD22301 Module to the height of the PLCC socket contacts.  Note, if required, chamfer the top face edge of the plastic square if it fouls the bottom of the socket contacts.  Cut a 17mm x 3mm rectangle from 1mm thick plastic for use as a spacer to wedge the inserted RFD22301 Module against the wired PLCC socket contacts.

The completed socket should look something like this.  The RFD22301 Module can then be pressed into the socket for programming.

A full RFD22301 module Breakout Shield is more difficult to fabricate as it involves machining a PLCC32 (2x7+2x9) socket to accommodate a RFD22301 module so that socket pin contact is made to either side of the module.  First remove all contacts from the PLCC socket (which can usually be readily disassembled), mill the socket to fit the RFD22301 module as shown, and then re-insert contacts to mate with the RFD22301 module.

Follow the procedure described above for making a shield base using stripboard and stackable headers.  Connect all PLCC socket contacts connecting to RFD22301 module pins (RESET, +3V, GND, and GPIO0 to GPIO6) to the corresponding stackable header pins.

Hope this is useful for a homemade RFD22301 module socket.

aeolus

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Re: RFD22301 Breakout Using PLCC Sockets
« Reply #1 on: April 12, 2016, 11:09:32 AM »
Very Nice!