Easy IoT is a simplest IoT Solution presented by DFRobot
By s.ferry
#44492
Hi,

First of all, I am new to GSM/GPRS. This is my first project using it.

I bought several of these A9 pudding modules for a PCB I have designed using an ESP32 and LoRa 868MHz radio transceiver. The project is a gateway, receiving data from several ESP32 LoRa nodes and forwarding the data to ThingSpeak. However, before I put the boards together, I have been testing the ‘puddings’ using my PC terminal to send AT commands to the board. The commands are taken from a randomnerdstutorial sketch using a SIM800

The following are the commands sent and the responses from the pudding (I have removed the OK responses which are not relevant)
Code: Select all
AT+CGATT=1
+CGATT:1
 
AT+CIPSTATUS
+CIPSTATUS:
STATE:IP INITIAL
 
AT+CSTT="internet"
OK
 
AT+CIPSTATUS
+CIPSTATUS:
STATE:IP START
 
AT+CIICR
OK
 
AT+CIPSTATUS
+CIPSTATUS:
STATE:IP GPRSACT
 
AT+CIFSR
10.8.254.23
 
AT+CIPSPRT=0
OK
 
AT+CIPSTART="TCP","api.thingspeak.com","80"
+CME ERROR: 50
 
AT+CIPSHUT
SHUT OK
As you see, everything goes OK, the status changes as I progress and it respires an IP address but the CIPSTART command returns an error. My SIM provider, Epic (Cyprus) has confirmed that the APN is correct and can’t see any reason for the error but apart from that, couldn’t help. Eventually, I am getting an IoT data sim but in the meantime, just using the Epic PAYG sim with data and credit for testing.

Can anyone offer any advice as to where I’m going wrong? Thanks in advance, Steve.