Data Sheet

LC840PA
Datasheet
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Signal Name
Pin No
I/O
Comments
Any_SIO/SPI_CS
54
I
SPI_CS is implemented using any spare SIO digital output pins to allow for
multi-dropping. On Laird devboard SIO_44 (pin54) used as SPI_CS.
5.9 I2C Interface
The I2C interface is an alternate function on SIO pins. The ProFLEX firmware does not use the I2C interface.
The two-wire interface can interface a bi-directional wired-OR bus with two lines (SCL, SDA) and has master/slave topology.
The interface is capable of clock stretching. Data rates of 100 kbps and 400 kbps are supported.
An I2C interface allows multiple masters and slaves to communicate over a shared wired-OR type bus consisting of two lines
which normally sit at VDD. The SCL is the clock line which is always sourced by the master and SDA is a bi-directional data line
which can be driven by any device on the bus.
IMPORTANT: You must remember that pull-up resistors on both SCL and SDA lines are not provided in the module and
MUST be provided external to the module.
Table 20: I2C interface
Signal Name
Pin No
I/O
Comments
SIO_26/I2C_SDA
36
I/O
This interface is an alternate function on each pin, configurable by
smartBASIC. I2COPEN() in smartBASIC selects I2C function.
SIO_27/I2C_SCL
38
I/O
5.10 General Purpose I/O, ADC, PWM, and FREQ
5.10.1 GPIO
The 19 SIO pins are configurable by smartBASIC application script. They can be accessed individually. Each has the following
user configured features:
▪ Input/output direction
▪ Output drive strength (standard drive 0.5 mA or high drive 5mA)
▪ Internal pull-up and pull-down resistors (13 K typical) or no pull-up/down or input buffer disconnect
▪ Wake-up from high or low-level triggers on all pins including NFC pins
5.10.2 ADC
The ADC is an alternate function on SIO pins, configurable by smartBASIC. The ProFLEX firmware uses ADC to measure
module supply voltage.
The LC840PA provides access to 8-channel 8/10/12-bit successive approximation ADC in one-shot mode. This enables
sampling up to eight external signals through a front-end MUX. The ADC has configurable input and reference pre-scaling and
sample resolution (8, 10, and 12 bit).
5.10.2.1 Analog Interface (ADC)
Table 21: Analog interface
Signal Name
Pin No
I/O
Comments
SIO_05/UART_RTS/AIN3 – Analog Input
39
I
This interface is an alternate function on each pin,
configurable by smartBASIC. AIN configuration
selected using GpioSetFunc() function.
Configurable 8, 10, 12-bit resolution.
Configurable voltage scaling 4, 2, 1/1, 1/3, 1/3, 1/4,
1/5, 1/6(default).
SIO_04/AIN2/SPI_MISO – Analog Input
34
I
SIO_03/AIN1 – Analog Input
49
I
SIO_02/AIN0 – Analog Input
50
I
SIO_31/AIN7 – Analog Input
44
I
SIO_30/AIN6 – Analog Input
45
I