This project uses a Feather M0 microcontroller and a SIMCOM7600 LTE Glonass Module as a tracking device
One of the features of this project is that you can set configuration parameters on the go by SMS
| Sample message | Description |
|---|---|
| #*, server, http://iotnetwork.com.au:5055/, | Server and port configuration |
| #*, stationary, 300, | Period in seconds to save location if speed < 1 |
| #*, logging, 20, | Period in seconds to save location if speed >= 1 |
| #*, upload, 300, | Period in seconds to upload location saved |
| #*, recovery, 1, | When set recovery to 1, the device will send its location to server every 10 segs |
| #*, recovery, 0, | Disable revocery mode and return to normal working code |
| #*, sms, +00987654321, | Send SMS from tracker to especified number with location data, include country code(Ex. +00) |
The commands are character sensible so dont include blank spaces and dont forget to type all the ", " (commas) shown on the sample message
Modem with LTE and GPS/Glonass/Beidou features Aliexpress
The commands provided by SIMCOM can be found here Application note
This are the commands required for TCP/IP connections, this is not required for this modem model
| Command | Response | Description |
|---|---|---|
| AT+SAPBR=1, 1 | OK | To open bearer |
| AT+SAPBR=2, 1 | +SAPBR:1, 1, "10.89.193.1" | To query bearer |
| AT+SAPBR=0, 1 | OK | To close bearer |
You can make a POST/GET request with the followin set of commands
| Command | Response | Description |
|---|---|---|
| AT+HTTPINIT | OK | Init HTTP service |
| AT+HTTPPARA="CID", 1 | OK | Set parameters for HTTP session |
| AT+HTTPPARA="URL", "www.sim.com" | OK | Set parameters for HTTP session |
| AT+HTTPACTION=0 | OK / +HTTPACTION: 0, 200, 1000 | GET session start / GET successfully |
| AT+HTTPREAD | +HTTPREAD: 1000 / OK | Read the data of HTTP server |
| AT+HTTPTERM | OK | Terminate HTTP service |
On this especific module the GPS features are already enabled from boot, you can get the related documentation here Application Note
| Command | Response | Description |
|---|---|---|
| AT+CGPS=1, 1 / AT+CGPS=1 / AT+CGPSCOLD / AT+CGPSHOT | OK | Start GPS stand alone |
| AT+CGNSSINFO | +CGNSSINFO: 2, 06, 03, 00, 3426.693019, S, 15051.184731, E, 170521, 034216.0, 46.5, 0.0, 0.0, 1.2, 0.9, 0.9 | |
| GNSS Data |
| Value | Tag | Description |
|---|---|---|
| 2 | Fix mode 2=2D fix 3=3D fix | |
| 06 | GPS satellite valid numbers scope: 00-12 | |
| 03 | GLONASS satellite valid numbers scope: 00-12 | |
| 00 | BEIDOU satellite valid numbers scope: 00-12 | |
| 3426.693019 | Latitude of current position. Output format is ddmm.mmmmmm | |
| S | <N/S> | N/S Indicator, N=north or S=south |
| 15051.184731 | Longitude of current position. Output format is dddmm.mmmmmm | |
| E | <E/W> | E/W Indicator, E=east or W=west |
| 170521 | Date. Output format is ddmmyy | |
| 034216.0 | UTC Time. Output format is hhmmss.s | |
| 46.5 | MSL Altitude. Unit is meters. | |
| 0.0 | Speed Over Ground. Unit is knots. | |
| 0.0 | Course. Degrees. | |
| 1.2 | Position Dilution Of Precision. | |
| 0.9 | Horizontal Dilution Of Precision. | |
| 0.9 | Vertical Dilution Of Precision |
In order to get SMS we need to use the following set of commands, AT commands reference
| Command | Response | Description |
|---|---|---|
| AT+CSMS=0 | OK | Select SMS service |
| AT+CPMS="ME", "ME", "ME" | OK | Select SMS storage |
| AT+CMGF=1 | OK | Select SMS text format |
| AT+CNMI=2, 2 | OK | Show SMS notification when it comes |
| +CMT: "+61419847400", "", "21/06/21, 13:23:10+40" | SMS Notification, location, index | |
| Testing SMS commands | SMS Notification, location, index | |
| AT+CMGRD=0 | OK | Read and Delete SMS |
| AT+CNMA | OK | Send ACK to SMS sender |
| AT+CGNSSINFO | (*) +CGNSSINFO: 2... | GNSS Data |
(*) +CGNSSINFO: 2, 06, 03, 00, 3426.693019, S, 15051.184731, E, 170521, 034216.0, 46.5, 0.0, 0.0, 1.2, 0.9, 0.9
To disable RF features when they are not required we can use the following set of codes SIM7600 Series PCIE Hardware Design
| Command | Response | Description |
|---|---|---|
| AT+CFUN=1 | OK | Enable RF |
| AT+CFUN=0 | OK | Disable RF |
The full list of commands can be found here: AT commands reference some additional commands used on this project are descrived bellow
| Command | Response | Description |
|---|---|---|
| AT+CMEE=2 | OK | Enable verbose error codes |
| AT+CGMM | OK | Get modem model |
| AT+GSN | OK | Get IMEI |
| AT+CGREG? | OK | Get Network status |
| AT+CGREG=1 | OK | register to network |
| AT+CSQ | OK | Network signal level |
| AT+CFUN=6 | OK | Reset device |
More information about the modem can be found here: Hardware Design