I have an express app running on firebase functions. I have tested invoking the function from my browser to write data to my database and it works perfectly fine. I also set the "Cloud Functions Invoker" permission to "allUsers".
My problem is, I need to send sensor data collected on an Arduino UNO to my cloud firestore through a SIM800 GPRS module (Making an HTTP request to my firebase function). I have tried AT+HTTPSSL=1 to enable SSL, but when sending the request I get a 606 response, which means "SSL alert message with a level of fatal result in the immediate termination of the connection" according to the SIM800 Series_SSL_Application Note_V1.01 documentation.
I have tried sending requests to an HTTP server hosting a PHP script and it worked fine, and from there I am able to use curl to do an HTTPS request to my firebase function, and it works fine, but it takes minutes to refresh my database, which is undesired.
Please let me know if there is a way to invoke a Google cloud function using the mentioned hardware. If not, what would you do in my situation?
Thanks in advance!