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IoT Node(A)



IoT Node(A) is one of Docker Pi series module.
IOT Node(A) = GPS/BDS + GSM + Lora.
I2C directly controls Lora, sends and receives data, controls the GSM/GPS/BDS module through SC16IS752, the mainboard only needs I2C support.
Support Raspberry Pi and other similar products.


  • DockerPi Series
  • Programmable
  • Control directly(without programming)
  • Extend the GPIO Pins
  • GPS/BDS Support
  • GSM Support
  • Lora Support
  • Can Stack with other Stack board
  • Independent of the mainboard hardware (require I2C support)

Official Compatibility Test

Not only support the following development boards, other development boards can be compatible if they have I2C peripherals. (Note: some software changes may be required)

Platform DockerPi IoT Node(A) Notes
Raspberry Pi All Platform Not Include CM Series & EOL Platform


GPRS section

  • 1. Low power consumption, standby sleep current <1mA
  • 2. Support GSM/GPRS four frequency bands, including 850, 900, 1800, 1900MHZ;
  • 3. GPRS Class 10;
  • 4. Support GPRS data service, maximum data rate, download 85.6Kbps, upload 42.8Kbps;
  • 5. Support standard GSM07.07, 07.05 AT commands, and access the serial port through I2C interface conversion.
  • 6. AT commands support standard AT and TCP/IP command ports

GPS section

  • 1. Support BDS/GPS joint positioning
  • 2. Support A-GPS, A-BDS
  • 3. Support standard SIM card

LORA section

  • 1. Transmission distance:500 Meters (RF parameters: 0x50 @ China City)
  • 2. Support FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation methods
  • 3. Ultra-high receiver sensitivity as low as -141 dBm
  • 4. Support preamble detection
  • 5. Packet engine with CRC, up to 256 bytes
  • 6. LORA transceiver indicator
  • 7. Easy TX/RX by Docker Pi

Mechanical Drawings

Lora mechanical.png



Package Include

  • 1 x IoT Node(A) Board
  • 1 x Instructions
  • 4 x M2.5*12 + 6 Copper stick
  • 4 x M2.5*6 Nut
  • 4 x M2.5*6 Half-round head screw
  • 1 x 433MHz L-Shaped Tape Antenna
  • 1 x 2.4GHz PCB Antenna
  • 1 x GPS/BDS High Gain GPS Built-in Ceramic Active Antenna

On Board Modules Documentations

Technical Details

A9G Module

  • A9G module offers two serial port.
  • Use I2C <=> UART bridge for communication.
Serial Port Module name
/dev/ttySC0 GSM
/dev/ttySC1 GPS/BDS

Register Map

Register Address Function Value
0x01 LORA_TX1 Lora TX Buffer 1 - User Data
0x02 LORA_TX2 Lora TX Buffer 2 - User Data
0x03 LORA_TX3 Lora TX Buffer 3 - User Data
0x04 LORA_TX4 Lora TX Buffer 4 - User Data
0x05 LORA_TX5 Lora TX Buffer 5 - User Data
0x06 LORA_TX6 Lora TX Buffer 6 - User Data
0x07 LORA_TX7 Lora TX Buffer 7 - User Data
0x08 LORA_TX8 Lora TX Buffer 8 - User Data
0x09 LORA_TX9 Lora TX Buffer 9 - User Data
0x0a LORA_TX10 Lora TX Buffer 10 - User Data
0x0b LORA_TX11 Lora TX Buffer 11 - User Data
0x0c LORA_TX12 Lora TX Buffer 12 - User Data
0x0d LORA_TX13 Lora TX Buffer 13 - User Data
0x0e LORA_TX14 Lora TX Buffer 14 - User Data
0x0f LORA_TX15 Lora TX Buffer 15 - User Data
0x10 LORA_TX16 Lora TX Buffer 16 - User Data
0x11 LORA_RX1 Lora RX Buffer 1 - User Data
0x12 LORA_RX2 Lora RX Buffer 2 - User Data
0x13 LORA_RX3 Lora RX Buffer 3 - User Data
0x14 LORA_RX4 Lora RX Buffer 4 - User Data
0x15 LORA_RX5 Lora RX Buffer 5 - User Data
0x16 LORA_RX6 Lora RX Buffer 6 - User Data
0x17 LORA_RX7 Lora RX Buffer 7 - User Data
0x18 LORA_RX8 Lora RX Buffer 8 - User Data
0x19 LORA_RX9 Lora RX Buffer 9 - User Data
0x1a LORA_RX10 Lora RX Buffer 10 - User Data
0x1b LORA_RX11 Lora RX Buffer 11 - User Data
0x1c LORA_RX12 Lora RX Buffer 12 - User Data
0x1d LORA_RX13 Lora RX Buffer 13 - User Data
0x1e LORA_RX14 Lora RX Buffer 14 - User Data
0x1f LORA_RX15 Lora RX Buffer 15 - User Data
0x20 LORA_RX16 Lora RX Buffer 16 - User Data
  • 0x01 - 0x10 Write Only.
  • 0x11 - 0x20 Read Only.

Register Address 0x22
Name - SpreadingFactor SignalBandwidth ErrorCoding
Default Value 0 1 0 1 1 0 1 1
Description Reserved Band range 7-12 Spread spectrum bandwidth 6-9 Effective data ratio 1-4
  • It is recommended to keep the default unless you know the meaning of the LORA parameter.

Register Address 0x23
Default Value 0 0 0 0 0 0 0 0
Description L_SET G_RESET Reserved Reserved Reserved Reserved L_RXNE L_TX
  • L_SET(Write Only)
  1. Write 1 to set parameters from 0x22 to LORA Module.
  2. Write 0 not effect
  • G_RESET(Write Only)
  1. Write 1 to reset A9G Module
  2. Write 0 not effect
  • L_RXNE(Read & Write)
  1. Write 1 cause error
  2. Write 0 to clear
  3. Read 1 means data has been received, please get the data from the register 0x11 - 0x20.
  4. Read 0 means no data available now.
  • L_SET(Write Only)
  1. Write 1 to send data,please fill in the data in register 0x01 - 0x10 before send.
  2. Write 0 not effect

How to use

How to assemble

  • Mount the Iot Node(A) board to Raspberry Pi
  • Hookup GPS antana and Lora antana to IPX port.
  • Screws the GPRS antana on the SMA port.

Configuring I2C(Raspberry Pi)

Run sudo raspi-config and follow the prompts to install i2c support for the ARM core and linux kernel
Go to Interfacing Options


then I2C






Replace /boot/overlays/sc16is752-i2c.dtbo(Raspberry Pi)

Replace /boot/overlays/sc16is752-i2c.dtbo file with this file: File:Sc16is752-i2c.zip

Replace dtbo sc16is752.png

Modify /boot/config.txt file and add following parameter:

Add dt sc16.png

And then save it and reboot Raspberry Pi.

  • After rebooting, two serial devices will be detected in following location:

How to use GPS Module with gpsd(Raspberry Pi)

A) First, replace the /boot/overlays/sc16is752-i2c.dtbo and make sure I2C is working properly.

  1. Replace sc16is752-i2c.dtbo [[1]]
  2. Configuring I2C[[2]]

B)Install gpsd tools.

sudo apt install gpsd gpsd-clients

C)Modify /etc/default/gpsd file and add following parameters:

GPSD_OPTIONS="-F /var/run/gpsd.sock"

D)Enter command i2cset -y 1 0x16 0x23 0x40 to reset the GPRS module.

E)Python Script For Open GPS:

import serial
import os
import time

# Restart gpsd service.
os.system("sudo systemctl restart gpsd.socket")
# Open serial port  
ser = serial.Serial('/dev/ttySC0', 115200)

i = 0

if ser.isOpen == False:
    print("Turn on GPS...")
    while True:
        size = ser.inWaiting() 
        if size != 0:
            ticks = time.time()
            response = ser.read(size)
            gps = str(response,encoding="utf-8")
            if(gps.find("OK") != -1):
                os.system("sudo cgps -s")  
                i = i + 1
                print("Waiting GPS Enable, If the time is too long, Please test outdoors:" + str(i))
except KeyboardInterrupt:

F)Save it and execute it:

python3 GPS.py 

How to use GPS Module with C(Raspberry Pi)

A)Install gpsd tools.

sudo apt-get install libgps-dev

B)Create source code and name it "gps.c"

#include <gps.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>

int main()
   int rc;
   struct timeval tv;
   struct gps_data_t gps_data;
   if ((rc = gps_open("localhost", "2947", &gps_data)) == -1)
      printf("code: %d, reason: %s\n", rc, gps_errstr(rc));
      return EXIT_FAILURE;
   gps_stream(&gps_data, WATCH_ENABLE | WATCH_JSON, NULL);

   while (1)
      /* wait for 2 seconds to receive data */
      if (gps_waiting(&gps_data, 2000000))
         /* read data */
         if ((rc = gps_read(&gps_data)) == -1)
            printf("error occured reading gps data. code: %d, reason: %s\n", rc, gps_errstr(rc));
            /* Display data from the GPS receiver. */
            if ((gps_data.status == STATUS_FIX) && (gps_data.fix.mode == MODE_2D || gps_data.fix.mode == MODE_3D) && !isnan(gps_data.fix.latitude) && !isnan(gps_data.fix.longitude))
               /* gettimeofday(&tv, NULL); EDIT: tv.tv_sec isn't actually the timestamp! */

               printf("latitude: %f, longitude: %f, speed: %f, timestamp: %lf\n", gps_data.fix.latitude, gps_data.fix.longitude, gps_data.fix.speed, gps_data.fix.time);
               //EDIT: Replaced tv.tv_sec with gps_data.fix.time
               printf("no GPS data available\n");
   /* When you are done... */
   gps_stream(&gps_data, WATCH_DISABLE, NULL);
   return EXIT_SUCCESS;


gcc gps.c -lm -lgps -o gps

Exec It!



How to use GPS Module with Python(Raspberry Pi)

The following code is recommended to be executed using Python 3 and install the gpsd-py3 library and GPS 2D/3D Fix:

import gpsd

# Connect to the local gpsd

# Get gps position
packet = gpsd.get_current()

# See the inline docs for GpsResponse for the available data

How to use GSM Module with PPPd(Raspberry Pi)

A) First, replace the /boot/overlays/sc16is752-i2c.dtbo and make sure I2C is working properly.

  1. Replace sc16is752-i2c.dtbo [[3]]
  2. Configuring I2C[[4]]

B)Enter command i2cset -y 1 0x16 0x23 0x40 to reset the GPRS module.

  1. After running the command, you need to wait a little, about 10 seconds.
  2. You can also use the following method to reset.[[5]]

C)Enter command sudo apt install ppp to install ppp tools.


D)Copy /etc/ppp/peers/provider to /etc/ppp/peers/gprs

E)Modify /etc/ppp/peers/gprs

  1. Line 10 : Please consult your service provider for the user (Example:cmnet).
  2. Line 15 : Please consult your service provider for the apn (Example:cmnet).
  3. Line 18 - Line 24:Recommended setting

F)Modify /etc/chatscripts/gprs (Change Line 34 to Line 35,Dialout Number May be NOT *99#)

Gprs ppp.png

G)Enter command sudo pppd call gprs to dial up.


H)Check your ppp config from your ISP.


I)Enter command ping -I ppp0 test your network (If Internet available and route table is correct)


J)Please keep the GSM signal good, otherwise the following will occur.


How to diagnose my GSM Module(Raspberry Pi)

The following code is recommended to be executed using Python 3 and install the smbus library:

import serial
import time
import smbus
import operator
import os

print("Waiting for initializing...")

bus = smbus.SMBus(1)    

ser = serial.Serial('/dev/ttySC0', 115200)

if ser.isOpen == False:
    print("Initializing A9G GPRS module.")
    print("GSM connecting...")
    i = 0
    while True:
        size = ser.inWaiting() 
        if size != 0:
            ticks = time.time()
            response = ser.read(size)
            ccid = str(response,encoding="utf-8")
            i = i + 1
except KeyboardInterrupt:

Exec the Test Script,based on the results of the implementation, we can diagnose the GSM module.

For example, the following return, CME ERROR 53 error tell us Power not good.

CME Code = GSM Equipment Related errors


Of course, the script also has a reset function. If you can display the CCID correctly, the reset is complete.


Press Ctrl-C to kill this script.

Dialout log reference(Raspberry Pi)

For quick troubleshooting, please refer to other documents for more details.

Script /usr/sbin/chat -s -v -f /etc/chatscripts/gprs -T cmnet finished (pid 1025), status = 0x0
Serial connection established.
using channel 1
Using interface ppp0
Connect: ppp0 <--> /dev/ttyUSB0
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x93623f70> <pcomp> <accomp>]
rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth pap> <magic 0xb90fa> <pcomp> <accomp>]
sent [LCP ConfAck id=0x1 <asyncmap 0x0> <auth pap> <magic 0xb90fa> <pcomp> <accomp>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x93623f70> <pcomp> <accomp>]
sent [LCP EchoReq id=0x0 magic=0x93623f70]
sent [PAP AuthReq id=0x1 user="cmnet" password=<hidden>]
rcvd [LCP EchoRep id=0x0 magic=0xb90fa]
rcvd [PAP AuthAck id=0x1 "Login ok"]
Remote message: Login ok
PAP authentication succeeded
sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr> <ms-dns1> <ms-dns2>]
rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr>]
sent [IPCP ConfAck id=0x1 <compress VJ 0f 01> <addr>]
rcvd [LCP ProtRej id=0x2 80 fd 01 01 00 0f 1a 04 78 00 18 04 78 00 15 03 2f]
Protocol-Reject for 'Compression Control Protocol' (0x80fd) received
rcvd [IPCP ConfNak id=0x1 <addr> <ms-dns1> <ms-dns2>]
sent [IPCP ConfReq id=0x2 <compress VJ 0f 01> <addr> <ms-dns1> <ms-dns2>]
rcvd [IPCP ConfAck id=0x2 <compress VJ 0f 01> <addr> <ms-dns1> <ms-dns2>]
not replacing default route to eth0 []
local  IP address
remote IP address
primary   DNS address
secondary DNS address
Script /etc/ppp/ip-up started (pid 1034)
Script /etc/ppp/ip-up finished (pid 1034), status = 0x0

How to use Lora TX & RX with C(Raspberry Pi)

It must be transferred between the two IOT Node(A). The content sent by itself cannot be received by itself.

  • How to Send:After filling the data into register 0x01 - 0x10, set the L_TX bit to start sending data.
#include <stdio.h>
#include <wiringPi.h>
#include <wiringPiI2C.h>

int main(){
  int fd;

  fd = wiringPiI2CSetup(0x16);


  • How to Send Receive:Check L_RXNE bit,If set,new data arrived,this flag must be manually clear.
#include <stdio.h>
#include <wiringPi.h>
#include <wiringPiI2C.h>

int main(){
  int fd;
  int ret[4];

  fd = wiringPiI2CSetup(0x16);

  if (wiringPiI2CReadReg8(fd, 0x23) & 0x02 )
    ret[0] = wiringPiI2CReadReg8(fd, 0x11);
    ret[1] = wiringPiI2CReadReg8(fd, 0x12);
    ret[2] = wiringPiI2CReadReg8(fd, 0x13);
    ret[3] = wiringPiI2CReadReg8(fd, 0x14);

    printf("Received data:0x%02X,0x%02X,0x%02X,0x%02X",ret[0],ret[1],ret[2],ret[3])
    printf("No data Received yet~")

How to use Lora TX & RX with Python(Raspberry Pi)

The following code is recommended to be executed using Python 3 and install the smbus library.

It must be transferred between the two IOT Node(A). The content sent by itself cannot be received by itself. Please save it as a py script for execution.

  • How to Send:After filling the data into register 0x01 - 0x10, set the L_TX bit to start sending data.
import time
import smbus
import os
import sys

bus = smbus.SMBus(1)    

    data_list = [170,85,165,90] 
    # write data to register and then the data will be send out. 
    for index in range(1,len(data_list) + 1):
        bus.write_byte_data(0x16,index,data_list[index - 1])
        print("LORA send data to %d register %d data" %(index, data_list[index - 1]))
except KeyboardInterrupt:
  • How to Send Receive:Check L_RXNE bit,If set,new data arrived,this flag must be manually clear.
import time
import smbus
import os
import sys

bus = smbus.SMBus(1)    
recv_data = [] 

    if bus.read_byte_data(0x16,0x23) & 0x02 :
        # manually clear L_RXNE
        register_list = [0x11,0x12,0x13,0x14]
        # read out data
        for index in range(0x11,len(register_list) + 0x11):
            recv_data.append(bus.read_byte_data(0x16, register_list[index - 0x11]))

        print("Received data:")
    else :
        print("No data Received yet~")
except KeyboardInterrupt:

Special description of I2C bandwidth

  • The limit of the I2C speed is 400kHz,due to the I2C protocol,so the single device effective bandwidth is lower than 320kbps,multi device effective bandwidth is lower than 160kbps.
  • The limit of the I2C <=> UART Bridge speed is 115200bps.
  • When GPS and GSM work at the same time, I2C bandwidth is insufficient,because 115.2kbps * 2 = 230.4kbps,so some data will be overflow.
  • Reducing the baud rate of GPS and GSM communication can improve the communication bandwidth shortage.
  • Stacking other DockerPi modules may take up extra I2C bandwidth.
  • At usually, the network data speed is slow, so the GSM bandwidth is not full, so there is no overflow problem.


  • Q: GPS Status always NO FIX?
 A: GPS must be used outdoors,It may take up to 15 minutes for the first use.
  • Q: Unable to open serial port?
 A: Check permissions, dialout groups, and whether other software is occupying the serial port.
  • Q: PPP No internet access,How can I do?
 A: Consult your ISP service provider.
  • Q: Dose CDMA Support?
 A: No.
  • Q: I can't use the BDS system.
 A: Available only in China and parts of Asia.
  • Q: The network speed is too slow.
 A: 2G network is unable to compare speed with 5G network.
  • Q: Can I use other GPS antennas?
 A: Yes, but please be careful not to use antennas that exceed the GPS power limit.
  • Q: My SIM card has no signal, but it works fine on the mobile phone. Why?
 A: Make sure your location 2G network is well covered & Make sure your carrier does not ban your 2G network.
  • Q: PPP have internet access,but can't ping any website?
 A: Try to run route add -net ppp0
  • Q: GSM Connect script failed,How to do?
 A: Try to run i2cset -y 1 0x16 0x23 0x40 and wait 1 minutes.If Failed,Please check your SIM card.
  • Q: Why I get "timeout sending Config-Requests"?
 A: Please check the antenna and 2G signal conditions..
  • Q: Could not determine local IP address,How can I do?
 A: The program will try again until it fails. If it fails, please try again later, or contact the ISP to resolve it.
  • Q: Could not determine remote IP address,How can I do?
 A: Your ISP limits how your SIM is used.
  • Q: What is China Dialout Number?
 A: WCDMA(*99#) CDMA(#777) TD-SCDMA(981#) GPRS/EGDE(99**1#)
  • Q: What is Other Region Dialout Number?
 A: Ask your ISP provider.
  • Q: pppd call gprs can dial successfully but ping -I ppp0 fail,How can I do?
 A: If there is no problem with the previous script, if you run pppd call gprs succes, and ifpconfig can view the ppp0 network card. However, if you have enabled Ethernet eth0 before dialing, you can use the ppp0 NIC to ping the specified ip or domain name ping -I ppp0 and it will not succeed for two reasons. One is the default gateway in the routing table. It was generated by eth0 before, and one is the default dns server address.After the defaultroute is enabled in the pppd script, pppd will add a default gateway information to the routing table after dialing successfully. However, because there is already a default gateway, the addition fails. The default gateway is still set by the previous eth. Before pppd call gprs we should first route del default to delete the default route (preferably write a script to delete the default route - dialing and other operations).
  • Q: Dial stability is relatively poor, Why?
 A: Because 2G coverage is getting lower and lower, you can use a more powerful antenna or add the lcp-echo-interval parameter.
  • Q: Why I get UnicodeDecodeError: 'utf8' codec can't decode byte 0xXX ?
 A: Please refer => IoT_Node(A)_SKU:_EP-0105#Replace_.2Fboot.2Foverlays.2Fsc16is752-i2c.dtbo.28Raspberry_Pi.29


  • IoT,Lora,GPS,GPRS,GSM,Node,radio devices,BDS