SIM908 Shield


I'm assisting a friend/collaborator in Cuba who is attempting to use a Waveshare SIM908 phone shield for a project he is working on. He is having difficulties getting it to function properly, and I was wondering if anyone has any experience working with this specific shield. I am having a very hard time finding any documentation for it and no other projects that use this shield specifically.

Now before you refer me to the condescending post that exists basically asking the same thing, I've checked it and maybe my browser is broken but the Waveshare website doesn't really seem to work...getting server error windows when I try to click on any links from the one page that opens (which is the page for this shield). If that's crazy then would someone let me know?

I know it is hard/annoying to respond to a post where you don't really know what the problem is, but I'm helping a buddy who has limited access to the internet. He says he thinks the problem lies in how he has the jumpers set, and I'm wondering if some pins need to be changed in the libraries to work with this shield. I have limited, cut and paste, sort of knowledge with arduinos, but haven't used this shield either.

Anyone with experience with this specific shield I would greatly appreciate your ear! This project is for the Havana Biennial in May, so weirdly, there is a rush (again, that's Cuba). I'll send you an appreciative art.
Thank you,

I've just been to the Waveshare web site and downloaded the Development resources pack - it wasn't quick but it did download.

In there are some examples, even though they have a 'c' suffix they are actually Arduino sketches.

If you have any specific questions I'll be happy to help if I can.


I have bought Waveshare SIM908 phone shield yesterday and I managed to get UNO r3 to talk to it after many attempts.

What I was missing is that I need to configure the jumpers on the shield to connect ( CTL RX & DUINO RX ) together and (CTL TX & DUINO TX) together.

before that the jumpers where configured to connect to USB rx and tx.

So after you configure the jumpers, you can easily run AT commands on the shield using Serial.println() function.

*Note: when doing this, you will not be able to upload programs from PC to arduino if the SIM908 shield is connected. you need to detach it, upload from pc, and re-attach it again.

hope this solves your problem.