I would like to know what is required in order to send and receive email using the GHI Cellular Radio Module.
I have not been able to find information about this. If it is possible, can anyone please point me to a source of information and or code which demonstrates this functionality.
Thanks.
For sending I just use a cloud email service and call their API, it’s easier to me than messing with SMTP.
@ andre.m - Thank you for your reply. My apologies for the lack of detail, I assumed ‘to send and receive email’ would suffice.
Via non-GSM/GPRS, or Ethernet / WiFi connected systems, the send email I am familiar with will, if smtp-based, implement an smtp client, create an instance of the message to be sent, create an instance of the smtp client using some smtp target endpoint, set properties such as authenticate, username, and password, send the message, and close the connection.
The receive email I am familiar with will, if pop3-based, implement a pop3 client, create an instance of the client, connect, handshake authentication details, mailbox statistics, fetch emails, and close the connection.
The above, using for instance Ethernet as an underlying transport, is familiar territory.
What I wish to achieve is the same, yet using GSM/GPRS as the underlying transport. I would like to know whether someone who is intimately familiar with the preparation and use of the GSM/GPRS transport in order to achieve the sending and receiving as above, could possibly point me towards anything which demonstrates this.
Many thanks.
@ andre.m - I believe this is what I missed, thanks.
Your reply “it could be the case its working with your module” appears to suggest that it “might also not work” with my module. If this is so, could you be more specific please, i.e. are there some verions of the module (or SIM900 module) on which ppp presents issues?
@ andre.m - Thanks
There is indeed an issue with some other modules but GHI has identified this after I got them to test with the same module I am using and they have confirmed that a fix will be coming in November for this. I am hoping it arrives early November as my design is getting close to final coding and I want to include PPP as part of the system to be able to upload data to a server.
To do SMTP once you have the PPP should be quite easy as the protocol is well documented and you may even be able to port some C code as there are lots of source out there for it.
@ Dave - Many thanks for this additional info. Knowing that some issues are being experienced really helps. I found your and other comments regarding this on the forum.
Regarding the pwrkey / power-up issue, it is also possible to use a combination of outputs on the SIM900 in order to determine the exact state of the chip. If one combines Netlight and Status, this works in most cases. Some designs also monitor DTR, yet I have not found the need for it on my designs.
In secion 4.12 Network Status Indication (pg33 of SIM900 HW Design pdf) provides the behaviour on the Netlight pin, which is unfortunately not exposed to a readily accessible socket. With some careful soldering gymnastics (solder to SIM900 side of R8, see schematic of Cellular module) one could hook this pin up to any unused GPIO input using a breakout module. The Status pin of the SIM900, which is also not exposed to a readily accessible socket, and is LOW when the chip is in power down state, can be used in combination as an indicator of state of power (4.2.2.1 pg18 and pg19 of SIM900 HW Design pdf). This can thus also be hooked up to a GPIO input using a breakout module (solder to SIM900 side of R13, see schematic of Cellular module). GPIO inputs should be connected to Netlight and Status pins via say 4K7 resistors as a precaution. Using these two signals to determine module state should suffice.
Now that PPP is working, I am looking for an SMTP email option. I’ve found one but it does not offer authentication with the server which is needed for me to use the SMTP server that I use.
Did you find anything that will work on the NETMF platform?
The MFToolkit has one but it does not work with NETMF.
Are you sending only? If you don’t have to use your own mail server you could use SendGrid. They have a free version that can send up to 12000 emails a month with no credit card. They have a web API that you can use to send emails.