CY8CKIT-026 CAN and LIN Shield Kit Guide, Doc. No. 002-03798 Rev. *C
20
Hardware
CAN2_TX and CAN2_RX pins need to be connected to the CAN TX pin, CAN_RX pin of the PSoC
(microcontroller) respectively, using external connecting wires. CAN2_EN pin is used enable/disable
the transceiver which should be connected to the CAN_EN pin of the microcontroller. The trans-
ceiver is enabled by default. These connections are not hard-wired on the board so that maximum
flexibility for the CAN pin placement in the microcontroller is provided.
3.3
LIN Physical Layer Transceiver Circuits
The CY8CKIT-026 has two LIN transceivers. Since some PSoC 4 devices support two LIN slaves,
these two transceivers enable you to use both of them simultaneously.
The two LIN physical layer transceiver circuits on the shield board use a TJA1020 LIN
transceiver device. This device translates high-voltage LIN bus signals to and from digital CMOS
signals with standard TTL voltage levels.
Three signals are used between each LIN circuit and the LIN (PSoC 4) controller. For the LIN1 cir-
cuit, the three signals are: LIN1_RX, LIN1_TX, and LIN1_NSLP. For the LIN2 circuit, the signals are:
LIN2_RX, LIN2_TX, and LIN2_NSLP. Data signals on the LIN bus are sent to the PSoC by the
LINx_RX signal. Data signals driven by the PSoC on the LINx_TX signal will be driven onto the LIN
bus. The LINx_NSLP signals are used to put the LIN transceiver device in and out of sleep.
By default, there are no pull-up resistors on the LINx_TX signals. A pull-up resistor footprint is pro-
vided (R25 on LIN1_TX and R10 on LIN2_TX) on each LINx_TX signal if you want to have a pullup
resistor on this signal. See the
device datasheet for details on each of the three signals of
the LIN transceiver.
3.3.1
LIN Bus Connectors
shows the pinout of both of the 3-pin LIN connectors (J14 for LIN1 transceiver and J5 for
LIN2 transceiver) on the shield board.
Figure 3-6. LIN Connector Pinouts
By default, the jumpers J16 and J7 are populated. These connect pin 3 (VBAT1) of the LIN1
connector and pin 3 (VBAT2) of the LIN2 connector to the VIN power rail of the Shield Kit,
respectively. This is useful if you want to power up other LIN nodes/analyzers through either of the
LIN connectors, or if you want to power the Pioneer Kit and shield board from the power supply
(12 V) of some other LIN node (LIN analyzer).
