SPRUIW8 November 2020
The LaunchPad has the ability to connect to two independent linear or rotary encoders through the F28002x on-chip eQEP interfaces: Header J12 is connected to eQEP1 and header J13 is connected to eQEP2. By default, this connection is not active and the GPIOs are routed to the BoosterPack connectors. The eQEP signals are routed through TI SN74LV4053A Triple 2-Channel Analog Multiplexer/Demultiplexer ICs (U11/U14). Once the eQEP signals have been selected through U11/U14, the 3.3 V signals are stepped up through a TI SN74LVC8T245 Level Translator (U13) to 5 V at the connectors. Switch S5 controls the select inputs of the ICs to configure the eQEP signal destinations to be either the J12/J13 connectors or BoosterPack headers, as described below in Table 3-3.
QEP1 SEL (LEFT) |
QEP2 SEL (RIGHT) |
QEP1 Signals (GPIO44/37/43) |
QEP2 Signals (GPIO14/25/26) |
---|---|---|---|
0 (down) | 0 (down) | J12 | J13 |
0 (down) | 1 (up) | J12 | BP Headers |
1 (up) | 0 (down) | BP Headers | J13 |
1 (up) | 1 (up) | BP Headers | BP Headers |