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Timothy Woo edited this page Jul 31, 2018 · 63 revisions

Here is a list of commonly-asked questions and issues. But before we begin, probably the biggest "issue" users have is trying to use the Hologram SIM card in Europe or other places where the SIM card doesn't support LTE CAT-M1 or NB-IoT networks (these are new technologies and Hologram hasn't partnered with everyone yet). If this is your case, please get an LTE CAT-M1 or NB-IoT SIM card from a local provider and it should work fine.

General Questions

Q: What boards is this shield compatible with?

A: This shield is directly compatible with 5V Arduino boards that have the standard Arduino header configuration and software serial RX support on pin 10. This includes Arduino Uno, Mega, and Leonardo. However, feel free to manually wire up the board instead of using it as a "shield" (in the sense of the term) to make use of the additional hardware serial ports on many Arduino boards including Arduino Mega, Due, Zero, and many more. This will allow you to use a higher baud rate (115200) without changing the default baud of the SIM7000 module. Please refer to the pinout documentation

Q: Does this shield work with Raspberry Pi?

A: Certainly! You just have to wire it up externally and I've included full documentation of the shield's pinouts. Note that since the Raspberry Pi runs on 3.3V logic you will need to follow the instructions on how to supply your own logic voltage by using the solder jumper on the back of the board. Note: This feature is only implemented for boards during or after 1 Feb 2018.

Q: I live in XXXX country. Which version should I choose?

A: There are three versions of the shield and it's important that you select the right one! For help on this please visit this Github wiki page. Note that this shield does not work on traditional LTE like CAT-1, 3, 5, 6, etc., so make sure you have CAT-M1 or NB-IoT in your area, or in the case of SIM7000C and SIM7000E, you can also use 2G or 2.5G fallback.

Q: Does the SIM7000 shield have audio support?

A: Unfortunately, no, this shield doesn't currently have audio support. However, I'm planning on making a new high-speed LTE shield right after this one that does have audio so stay tuned! Also, voice over LTE (VoLTE) seems to be under development by SIMCom engineers.

Q: Do I need a LiPo battery for my shield?

A: SIM7000A shields usually run just fine without a LiPo battery and the battery was mainly introduced so that the SIM7000C and SIM7000E shields can operate on GSM which draws a lot of power (about 4-5 times more than CAT-M1). However, it's definitely safer to use a LiPo battery to completely eliminate the chances for it being sluggish to connect to the network and to prevent possible power cycling during higher current draws (it depends on the network too!). So bottom line, if you're a SIM7000A user you maybe can disregard the battery and just power up the Arduino and everything might run just fine, but if you're using the SIM7000C or SIM7000E version it would be best to get use a LiPo battery. However, if you're not using GSM you may be able to circumvent it via AT commands to make it only operate on CAT-M and NB-IoT modes.

Troubleshooting

Q: The SIM7000 power LED isn't turning on when I power my Arduino. Is that normal?

A: This is perfectly normal! The power LED only turns on when the PWRKEY pin is pulsed LOW. This is taken care of in the example sketches I provide, so after you upload and run the code the shield should turn on shortly thereafter! If the LED on the shield doesn't turn on shortly after running the example sketch, see the next section. The shield must be on in order for the Arduino to find and communicate with it! You can also manually use a jumper wire and touch the PWRKEY pin to GND for a second or two, then release and the module should power on a few seconds later.

Q: The shield still isn't turning on, even after running the example sketch.

A: In rare cases the physical connection between the stacking female headers and the Arduino headers may not be entirely secure. To debug the problem, try using a male-to-male jumper wire to temporarily connect the PWRKEY pin to GND for less than half a second or so and see if the shield turns on. If it does, the physical connection of the headers might be an issue. To remedy this, tin the stacking female header contacts (mainly 5V/GND, TX/RX, and PWRKEY pin) with a small amount of solder to make the connection more secure and see if that helps.

Q: The shield always measures about 3600mV (or 4200 for v5 shields) regardless of my battery level. Why is that?

A: If you don't have a battery connected to the shield The SIM7000 module will operate on a fixed voltage and therefore the supply voltage it measures will always be around the same value.

Q: My shield isn't connecting to the network with a SIM card is inserted. How do I fix this?

A: The first thing you should do is make sure your SIM card is activated online. For a Hologram SIM card activate it on the Hologram dashboard. When activating you should also make sure you have the appropriate zone selected (zone 1 or 2). Next, in the Arduino code go to the line that says "fona.setGPRSNetworkSettings(F("hologram"));" and make sure you have the right APN settings entered. By default it's set to work with a Hologram SIM card. Also check to make sure the antenna is properly connected (remember, the antenna wires criss-cross). After that's done, run the "FONA_LTE_Test" sketch and enter the command "n" to see the network registration. If it says "Searching" wait a little bit and see if it connects. If it doesn't, enter the command "G" to enable GPRS and set the APN then see if it connects to the network. Some networks are simply not supported and I cannot guarantee that this shield will work with all SIM cards. I can confirm that the Hologram SIM card works on the Verizon network in the USA, and the AT&T Trio SIM card also works in the USA. Anything other than Verizon or AT&T is not guaranteed to work but please let me know if you did get another carrier working!

Q: My shield is constantly rebooting when I plug in a SIM card. What's causing this?

A: This is a common problem that occurs when you don't have a LiPo battery connected to the shield and is particularly important for SIM7000C, E, and G modules which support GSM fallback (which draws lots of current). If you get this issue and are sure you have CAT-M1 or NB-IoT connection in your area but want to try it without using a battery, try using "AT+CNMP=38" to set the module to only use LTE mode (and not GSM) and also "AT+COPS=0".

Q: I've done everything right and my module sees available networks with AT+COPS=? but I can't connect to them

A: If you simply cannot connect to the network and it always says not connected or searching, try running the command AT+CGDCONT=1,"IPV4V6","hologram" and see if it then connects. It should then either automatically connect to the network but if it doesn't, use AT+COPS to connect to one of the networks listed out from AT+COPS=?

Q: I have a SIM7000E and sometimes the module will randomly crash and won't reset until I pulse the module's reset pin or reset power to it. What's causing this?

A: This particular problem was reported by a user of the SIM7000E running firmware version 1351B03SIM7000E and was fixed by updating the firmware version to 1351B05V01SIM7000E.

Getting Help

In order to get the most efficient support, if you can't solve your problem after reading the FAQ above please copy/paste and fill out the info below and include this in your email for support:

Problem Description: Not turning on, not connecting to network, not able to establish serial communication with the shield, power cycling, etc. (please be descriptive)

Country: USA, Norway, Australia, etc.

Hardware: Arduino Uno, Mega, Leonardo, Raspberry Pi, Espruino Pico, etc. (Please describe your setup)

Modem: SIM7000 shield and version (A-A, A-V, C, E, G)

SIM Card: Hologram SIM, AT&T Trio SIM, other? Is the SIM registered online?

3.7V LiPo Battery (>500mAH): Yes/No? NOTE: If your shield power cycles (turns on, then turns off later by itself, etc. then you will need a LiPo battery to fix the problem!)

Software: Arduino IDE, LTE_Demo example sketch, etc?

Send the responses for the following AT commands (the easiest way to do this is via USB)

  • ATI
  • AT+CGMR
  • AT+CREG?
  • AT+CFUN?
  • AT+COPS?
  • AT+CSQ
  • AT+COPS=? (may take a 5-10s to run this command)