Brand:Eletechsup
Product Name:AMS1117 DC 5V to 3.3V for Arduino Base Resistor TTL Logic Level Converter Module
Description:
1 On board DC 5V to 3.3V DC-DC Step-Down Power Supply Buck Module,IC AMS1117-3.3;
2 On board 8 channels 5V to 3.3V(also 3.3V to 5V) Logic level converter,base Limiting resistor ;
3 Arduino Breadboard friendly;
4 2.54 pin
5 for IIC I2C UART SPI etc.
6 PCB size:25* 15mm
Typical applications:
NRF24L01 to Arduino/AVR/PIC MCU
SI4432 to Arduino/AVR/PIC MCU
CC1101 to Arduino UNO/AVR/PIC/STM32 MCU
Level conversion principle:
Between 5V and 3.3V level plus 470 ohm current limiting resistor, to avoid being burned of 3.3V port.
So, when the LOW side no-load, HIGH side plus 5V level,LOW side test is still at 5V level，vice versa.
This is a normal phenomenon, not the level conversion function does not work.
Schematics：