1. LED

There are six LEDs on the P4S-342 board.

LED Action
PWR / 3.3V / PWR5 supplying power > ON
STS running PHP > repeat On and Off in every second
not running PHP > briefly blinks 1 time at a time
UIO30 on board LED: connected with 30th pin of UIO0
UIO31 on board LED: connected with 31th pin of UIO0

※ PWR, STS, UIO30 and UIO31 are also located on the opposite side.

2. USB Host Port for Connection with WLAN adapter

P4S-342 provides a USB host port for an USB WLAN adapter. You can connect P4S-342 to Wireless LAN by connecting an WLAN adapter to this port.

※ Caution: Only adapters using Ralink RT3070/5370 chipsets are available.

3. Function Button (Func)

The function button is used for changing mode to the Button setup mode.

4. USB Device Port for connection with PC

The USB device port is to connect with PC. You can access to P4S-342 via development tool by connecting USB cable to this port. You can supply DC 5V power through this port. However, P4S-342 may not work properly in case of supplying power via this port only due to insufficient current.

5. Supplying Power

6. Reset Button (RESET)

This button is used for hardware reset.

7. Console Port

This port is console port for management.

Division Value
Signal Level 3.3V
Configuration 115,200bps / 8 Data bit / 1 Stop bit / No parity
Pin Assignment #1 - 3.3V, #2 - RX, #3 - TX, #4 - GND

8. JP1

Label Description Label Description
3.3V 3.3V Output PWR5 Output Supplied Power
GND Ground AREF ADC reference input port
AD0 ADC channel 0 AD3 ADC channel 3
AD1 ADC channel 1 AD4 ADC channel 4
AD2 ADC channel 2 AD5 ADC channel 5
GND Ground GND Ground
HT0 Hardware Timer 0 HT2 Hardware Timer 2
HT1 Hardware Timer 1 HT3 Hardware Timer 3
NSS/0 SPI - NSS / UIO0 #0 12 UART #1 RTS / UART #1 TxDE / UIO0 #12
SCK/1 SPI - SCK / UIO0 #1 13 UART #1 CTS / UIO0 #13
MISO/2 SPI - MISO / UIO0 #2 14 UIO0 #14
MOSI/3 SPI - MOSI / UIO0 #3 15 UIO0 #15
U0TX/4 UART #0 TX / UIO0 #4 16 UIO0 #16
U0RX/5 UART #0 RX / UIO0 #5 17 UIO0 #17
SCL/6 I2C - SCL / UIO0 #6 18 UIO0 #18
SDA/7 I2C - SDA / UIO0 #7 19 UIO0 #19
8 UART #0 RTS / UART #0 TxDE / UIO0 #8 20/DM UIO0 #20
9 UART #0 CTS / UIO0 #9 21 UIO0 #21
GND Ground SRO SPC Reset
PWR5 Output Supplied Power
3.3V 3.3V Output


If you connect this port, 3.3V is supplied to the analog input reference port (AREF).

10. Internal Battery

Internal battery is for saving log messages and operating RTC. Specification of this battery is as follows:

Parameter Value
Capacity 5.8mAh
Nominal Voltage DC 3V
Charge Voltage DC 2.8V ~ 3.1V

※ Refer to the datasheet for more information about the battery