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.
VIN
,GND
,PCE
,GIO1
,RESET
,TXD
,RXD
Pin Header 2:VBAT
,GND
,DTR
,RI
,RGIO0
,EINT
,DET
SIM7020_mini moduleVBAT
: Lithium battery input positive 3.7-4. 2VGND
: Lithium battery input negativeDTR
: Control module sleep and wake upRI
: Ringing indicatorRTC_GPI0O
: PSM mode indication, before and after entering PSM mode, the pin changes from high to lowRTC_EINT
: wake up from PSM mode, when this pin changes from high to low, exit PSM modeSIM DET
: SIM card insertion detectVIN
: Power input positive 5V (1A)GND
: negative powerPCE
: Power enable controlGPI01
: General purpose input/output portRESET
: reset controlTXD
: Serial transmissionRXD
: serial receiver