Nelson's Log

Consulting

Tue, 29 Sep 2026 00:00:00 -0700

I’m Chris Nelson, an independent engineering consultant based in California.

I help teams get hardware from idea to working prototype: electronics and embedded systems, wireless (BLE and RF), mechanical design, and 3D printing. I also enjoy the detective work, such as reverse engineering a device or protocol to find out how it really behaves. I’ve accumulated 15 years of experience working with industrial sensor networks, consumer electronics, and imaging products.

Reverse Engineering a Tactic RC radio

Sat, 18 Nov 2017 19:33:25 +0000

I'm working on reverse engineering the Tactic TTX300, a simple RC radio meant for RC cars. This radio comes with RTR Axial RC cars and can be purchased individually on Amazon for $50.

I've been looking for a good way to control RC equipment from a PC. Most RC equipment uses all-in-one chips, which are hard to source, use and program. Luckily the Tactic radios use an Atmel microcontroller and a Nordic nRF24L01+, both of which are easy and cheap to source from online retailers. Having the RF separated from the digital controls means I can reverse engineer the radio without needing a 2.4 GHz spectrum analyzer or SDR.

Worm gearbox design

Sun, 30 Apr 2017 00:16:33 +0000

simple worm gearbox

Was bored one afternoon and sketched up a simple worm gearbox.
Video if it in action:

Screen capture of the design process:

Volvo keychain

Sat, 07 Jan 2017 16:17:24 +0000

Simple case for an older volvo keycahin. The case fixes the broken keyring loop and keeps the two (disintegrating) halves from coming apart. The case is printed in a semiflexible plastic (PTFE) so the keychain can be pushed into the case.

File is up on github

Capacitive Scanning

Sat, 10 Dec 2016 18:39:16 +0000

When I am investigating something new, I like to try and imagine an ideal application for whatever it is I am investigating. This project grew out of one of these brainstorms. I was evaluating some capacitive sensors for work and was impressed at the range at which it could sense things. If I could move the sensor in a controlled manner, I could produce images representing the capacitance of an object.

About

Thu, 01 Dec 2016 04:46:39 +0000

My name is Chris Nelson and this is my work log.

Contact

Thu, 01 Dec 2016 04:46:38 +0000

Email me at contact [at] nelsonslog.com.

Wedding Cake Topper

Thu, 01 Dec 2016 04:46:37 +0000

This cake topper was done for some good friends of mine. The sculpture was an image imported into fusion 360 and traced out for a simple extrude. The cake topper is a sculpture lit by LEDs in the base.