Electronics

Information

ARRL Technical Information Service
B&B Electronics Data comm protocols incl RS485
Battery University
Discover Circuits
UofW EE Stores

E-Ham Forum for amateur radio, lots of reviews

Sensors

MEMS inertial sensors Hidden Markov Model-based Pedestrian Navigation System using MEMS Inertial Sensors

Schumann Resonance http://www.measurement.sk/2005/S3/Ondraskova.pdf

Tutorials

Op Amp Electronics basics of electronics
US Navy Training Course
WEB EE
Williamson Labs 90 tutorials

Electronics Suppliers

Action Electronics
Addicore Looks interesting. WeMos D1 R2 Arduino $10.45
Adafruit Industries *
All Electronics * surplus
Alltronics
Apex Jr audio and speakers
American Science & Surplus
Arrow Electronics
B&B Electronics Serial and Data communications
B.G. Micro
Circuit Specialists, Inc.
CTR Surplus
Digi-Key * distributor
Electronic Surplus
The Electronic Goldmine
HSC Electronics
Jameco surplus
Jaycar kits
JDR Microdevices
MakerFocus 2020-06-22 ESP32 modules, lots of other stuff
Mouser distributor
Marlin P Jones & Associates surplus, test equip
MCM Electronics repair & retrofit (Zashiban recommendation)
NightShade Electronics cheap ESP and Arduino boards, WeMos for $8.95
Ocean State Electronics
Q Kits * kits
PAiA musical instrument kits
Pololu
Radio Shack
Ramsey Electronics kits
Sparkfun Electronics * sensors, gps modules
Surplus Gizmos * Hillsboro OR
[http://www.surplussales.com/ Surplus Sales of Nebraska
Velleman Kits kits and components

My personal favorites are starred.

Amateur radio

AES
Tower Electronics Connectors and adapters
Universal radio

A few favorite books

The Art of Electronics, Horowitz and Hill
Mechatronics
Op Amps, Fredrick Hughes
Circuitbuilding for Dummies, H Ward Silver

See also

Materials