beaglebone-black - Flipbook - Page 91
BeagleBone Black
8.2.2 Expansion Connectors
A combination of male and female headers is used for access to the expansion headers on the main board.
There are three possible mounting con昀椀gurations for the expansion headers:
• Single no board stacking but can be used on the top of the stack.
• Stacking-up to four boards can be stacked on top of each other.
• Stacking with signal stealing-up to three boards can be stacked on top of each other, but certain boards
will not pass on the signals they are using to prevent signal loading or use by other cards in the stack.
The following sections describe how the connectors are to be implemented and used for each of the di昀昀erent
con昀椀gurations.
8.2.3 Non-Stacking Headers-Single Cape
For non-stacking capes single con昀椀gurations or where the cape can be the last board on the stack, the two 46
pin expansion headers use the same connectors. Figure 64 is a picture of the connector. These are dual row
23 position 2.54mm x 2.54mm connectors.
Fig. 8.4: Single Expansion Connector
The connector is typically mounted on the bottom side of the board as shown in Figure 65. These are very
common connectors and should be easily located. You can also use two single row 23 pin headers for each of
the dual row headers.
Fig. 8.5: Single Cape Expansion Connector
It is allowed to only populate the pins you need. As this is a non-stacking con昀椀guration, there is no need for
all headers to be populated. This can also reduce the overall cost of the cape. This decision is up to the cape
designer.
For convenience listed in Table 19 are some possible choices for part numbers on this connector. They have
varying pin lengths and some may be more suitable than others for your use. It should be noted, that the longer
the pin and the further it is inserted into the BeagleBone Black connector, the harder it will be to remove due
to the tension on 92 pins. This can be minimized by using shorter pins or removing those pins that are not
used by your particular design. The 昀椀rst item in**Table 18** is on the edge and may not be the best solution.
Overhang is the amount of the pin that goes past the contact point of the connector on the BeagleBone Black
Table 8.6: Single Cape Connectors
86
SUPPLIER
PARTNUMBER
LENGTH(in)
OVERHANG(in)
Major League
Major League
Major League
TSHC-123-D-03-145-G-LF
TSHC-123-D-03-240-G-LF
TSHC-123-D-03-255-G-LF
.145
.240
.255
.004
.099
.114
Chapter 8. Cape Board Support
