We now have plenty to choose from when it comes to NB-IoT development boards or shields, but so far pricing has not been very attractive, and the cheapest NB-IoT solution I found so far was probably Dragino NB-IoT Bee, a XBee compatible board going for $23.
But this morning, I saw an even cheaper NB-IoT board with SIM7020E 4G NB-IOT Mini development board selling for $14.30 on Electrodragon. Not quite the price of 2G solutions, but we’re getting there.
- NB-IoT Module – SIMCom SIM7020E module working globally with B1/B3/B5/B8/B20/B28 bands supported
- Nano SIM card holder and u.FL connector for NB-IoT
- Expansion – 9-pin unpopulated 2.54mm pitch header with 2x UART (3.3V / 5V), ADC, Boot, 3.3V, 5V and GND
- USB – 1x micro USB port that can be recognized by PC, but as Electrodragon puts it: “not sure how to use it”.
- Misc – Net LED, power key
- Power Supply – 5V via header (or micro USB port?); on-board LDO up to 12V (max 16V) 500mA
- Dimensions – 28x26mm
Beside its price, the other good things about this module are its size and global support. While there’s a USB port, it looks nobody knows how to use it yet, and interface would be done through the 3.3V or 5.5V UART. You’ll need to add a micro-controller boar, and a u.FL antenna, as well as your own NB-IoT SIM card, and you should be good to go for less than $25.
I could not find any Wiki for SIM7020, but you’ll find some documentation – including AT commands set – on SIMCom website. There’s also a guide on Instructables showing how to use SIM7020 module with Arduino, and which should be relevant to this board too.