Sim7020

Project Sim7020
SIM7020 NB-IOT modem
Status	In progress
Contact	bertrik
Last Update	2021-01-23

What

This page is about the SIM7020 NB-IOT module.

I plan to experiment with this kind of network connectivity for perhaps a bat activity monitor or air quality monitoring.

Update: this escalated quickly ... the NB-IOT stuff at t-mobile already seems dead: Chromium complained about an expired certificate for the https website, otherwise seems down (error 503).

wget says:

bertrik@zenbook:~$ wget http://portal.iot.t-mobile.nl/
--2021-01-23 19:01:06--  http://portal.iot.t-mobile.nl/
Resolving portal.iot.t-mobile.nl (portal.iot.t-mobile.nl)... 52.57.78.255
Connecting to portal.iot.t-mobile.nl (portal.iot.t-mobile.nl)|52.57.78.255|:80... connected.
HTTP request sent, awaiting response... 503 Service Unavailable: Back-end server is at capacity
2021-01-23 19:01:06 ERROR 503: Service Unavailable: Back-end server is at capacity.

bertrik@zenbook:~$ wget https://portal.iot.t-mobile.nl/
--2021-01-23 19:02:35--  https://portal.iot.t-mobile.nl/
Resolving portal.iot.t-mobile.nl (portal.iot.t-mobile.nl)... 52.57.78.255
Connecting to portal.iot.t-mobile.nl (portal.iot.t-mobile.nl)|52.57.78.255|:443... connected.
ERROR: The certificate of ‘portal.iot.t-mobile.nl’ is not trusted.
ERROR: The certificate of ‘portal.iot.t-mobile.nl’ has expired.
The certificate has expired

Hardware

I wired it up like this:

Connections

SIM7020	USB serial	Remark
G	nc	looped to SIM7020-K
R	TXD
T	RXD
K	nc	looped to SIM7020-G
V	3V3
G	GND
S	DTR

References

I followed roughly this guide:

• Ordered a SIM7020 and a starter kit, see https://www.hackster.io/voske65/arduino-nb-iot-with-sim7020-and-t-mobile-027f8f
• Account page: https://portal.iot.t-mobile.nl/auth/login