Sim7000C vs Sim7000E / NB-IoT/LTE/GPRS/GPS Expansion Shield

@claude69103. I’m having trouble getting SIM7000C working. Can you give more information on how you got it to work? Like what SIM and what pins you jumpered

Thanks
Priyath

Hi Mal,
Could please share your ideas to connecting DF 7000E directly bypassing the UNO. The board is not responding the AT commands, we are able to receive the response from the board when we hold boot button for 2 seconds. and connecting with TTL Converter (FT232RL USB to TTL Module) to power up externally.

We connected UART TX & RX with switch mode of D7 & D8? We also tried connecting UART TX & RX in - D7 & D8.

We also tried other options of our connection was as follows :

Tx of TTL Convertor - (D1) Tx of DFRobot shield

Rx of TTL Convertor - (D0) Rx of DFRobot Sheild

VCC of TTL Convertor - Vin of DFRobot Shield

GND of TTL Convertor - GND of DFRobot Shield

We tried on D0-D1 mode and D7-D8 Mode

Switch in D0 D1 Mode

D0 - Rx

D1 - Tx

Switch in D7-D8 Mode

D7 - Rx

D8 - Tx

While opening the serial port in Serial terminal. we are not getting AT Commands response from the DFRobot sheid

when we press BOOT Button at that time we are getting print statements as like +CPIN : READY +CFUN : 1 SMS READY But at the same time while typing AT we are not getting any response from the Board.

Hi,

Sounds like you are very close - if you are receiving the +CPIN message, you are getting RX from the TTL converter, as well as the shield. Process of elimination means that you should also be capable of sending to the unit.

Try the basics first - type ATZ and see if you get an “OK” back. If not, you likely have a wire in the wrong spot in one of two places:

  1. Your TX pin of the USB serial converter you are using, to the RX pin of the TTL converter, or
  2. The TX pin of the TTL converter, to the RX pin of the shield.

Since you already know that you have two of the four connection wires correct (assuming ground is ok between all three devices, and excluded from this count!), I would first:

  1. Verify which wires ARE the working wires, by disconnecting one of the wires on the shield (pin 7 or 8), and then verifying that you no longer receive the +CPIN messages on startup, then
  2. reconnect the wire, verify you are getting the +CPIN messages again, then
  3. disconnect a TX or RX wire between the TTL converter and your USB serial port (leaving ground connected in all instances)

Once you know which wires are responsible for receiving (which should be correct unless you have ground wrong as well), it will be the other wires that are likely causing your issue.

Be sure to have the grounds common between all three devices. This will be pin 5 on a DB9 plug, and the 0V on the shield and TTL converter.

How are you powering the TTL converter? I have some units from Altronics that require voltage from the shield to power the shift registers - it might now work, or in your case, only half work, if this isnt connected, or the correct voltage.

Sorry - I don’t have my rig set up atm to compare - its in the “too hard basket” for a while, since I got an alternative module to work instead.

Good luck!

2 Likes

Hi got SIM7000E Raspberry Pi HAT working with Telstra.

https://ruwanindikaprasanna.blogspot.com/2019/06/sim7000e-raspberry-pi-hat-australia.html

  1. Search for operators. I got errors several times for this command.

at+cops=?
+COPS: (1,“505 01”,“505 01”,“50501”,7),(0,1,2,3,4),(0,1,2)

OK

  1. Manually attach

at+cops=1,2,“50501”
OK

1 Like