Embedded Engineering Field Notes. Made by @jjmilburn.
Selecting an interface to the physical world
24 Oct 2018Shameless hiring plug.
10 Apr 2018Reasonable security questions to ask of your IoT device/ecosystem
09 Apr 2018How not to concurrently modify the IMR register on an STM32
11 Feb 2018A brief notice about a new blog series I’ll be authoring for Angaza.
12 Jul 2017While Bluetooth gets plenty of attention for providing sensor and accessory connectivity to Android devices, an older protocol introduced at Google I/O 2011 continues to promise widely compatible, no-pairing data wired data transfer.
08 May 2017Even if your product integrates a cellular module with an FCC certification, it does not mean that the integrated product is fine to sell on the open market. This post pulls together estimates from various sources to gain a rough estimate of total cost for RF-related certification on a product using a ‘certified’ cellular module.
18 Mar 2017While creating a UART protocol for use in a new product, it
became useful to connect a serial adapter from my host PC to the Vagrant
environment which held the protocol code and its dependencies. This approach
should work regardless of the UART converter model/brand (Prolific, FTDI, etc)
assuming that plugging the device in creates a /dev/ttyUSB[0-9] entry. This
guide is written for a *nix host platform (Ubuntu).
While hardware which intentionally radiates RF falls under FCC Part 15 in the US, other countries might not be so clear. This post introduces a few of the regulatory frameworks and bodies operative outside of the US which apply to GSM/cellular communications.
20 Jun 2015A “Relaxation Oscillator” is just a fancy name for a circuit which generates a repetitive output signal (Wikipedia says this must be nonsinusoidal). Most examples are for 50% duty cycle designs. Here, build one using the NXP NXC2200.
13 Oct 2014