I bough Sim7020_mini module. I put IOT Sim card, and plug-in antenna, connect Rx,Tx into USB-TTL, then put supply into VIN (5 volt), LED power was lid on. Arduino Serial Monitor set into 115200, but no character appear, also I enter AT, no answer. I already making sure my wiring. Measuring STATUS pin 42 showing 1.8 volt, means not active.

Schematic look like wrong, according to sim7020 Hardware design v1.02, to put SIM7020 to On we should give LOW pulse 1 second into PWRKEY. But STATUS pin still 1.8 volt.

May anyone has successful using this such module? Any clue?

First question about using SIM7020_mini Module

Thank you @hcheung for clue about 1.8 volt.

The SIM7020_mini module already equipped with logic level shifter between 1.8v and 3.3v.

I know SIM 7020C already Up, pin STATUS (42) is HIGH, pin NETLIGHT (41) blinking.

Here is my schematic, I just want to enter AT Command first. But on my Serial Monitor (Arduino) doesn't show any character received.


simulate this circuit – Schematic created using CircuitLab

When I type 'AT' it's echoed back to screen Serial Monitor. When I reverse Tx/Rx between SIM7020_mini module and USB-TTL, no character echoed. When I restart SIM7020_mini module, there is no character received by Serial Monitor.

  • Can you provide a picture of all the header pins naming? or a link to where you purchase the module?
    – hcheung
    May 2 at 11:45
  • Pin Header 1: VIN, GND, PCE, GIO1, RESET, TXD, RXD Pin Header 2: VBAT, GND, DTR, RI, RGIO0, EINT, DET SIM7020_mini module
    – Widoyo
    May 2 at 13:37
  • VBAT: Lithium battery input positive 3.7-4. 2V GND: Lithium battery input negative DTR: Control module sleep and wake up RI: Ringing indicator RTC_GPI0O: PSM mode indication, before and after entering PSM mode, the pin changes from high to low RTC_EINT: wake up from PSM mode, when this pin changes from high to low, exit PSM mode SIM DET: SIM card insertion detect VIN: Power input positive 5V (1A) GND: negative power PCE: Power enable control GPI01: General purpose input/output port RESET: reset control TXD: Serial transmission RXD: serial receiver
    – Widoyo
    May 2 at 13:44

1 Answer 1


My fault, AT command on Serial Monitor (Arduino IDE) should be ending with Carriage Return, while my Serial Monitor using New Line

Thank you for responses.

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