The Cheap Side
And over in China we have …
A breakout for the fairly accurate MPL31115A2, (can’t find any links to this! Leave a comment below if you find one.), temperature and pressure sensor. Runs off 3.5 to 5v and can drop down to 2uA in standby. Even at a 1Hz sampling rate it only consumes around 9uA.
And here’s a 3 channel low and high side current and voltage monitor running the INA3221 IC, which is accessible over I2C.
Apparently you can pick up a tiny GSM module for only US$8! This one runs the MTK6260M, (another link I can’t find! Let me know if you find it.), GSM module and if you’re lucky to be in a country with a running GSM network still you’ll be able to use it.
Remember the old 8051 CPUs? Well here’s a new take on an old CPU. This breakout has an updated 8051 CPU, (STC15F104W), that will run code 20% faster than the previous incarnation of this chip, (STC15F104E), along with 6 GPIOs.