- Making a tachometer for a grinding / polishing machine for telescope mirrors
- Massive scalability when querying metrics stored in Graphite
- multifactor authentication for distributed VPN mesh - part 3, VPN mesh
- multifactor authentication for distributed VPN mesh - part 2, token configuration, local OTP
- multifactor authentication for distributed VPN mesh - part 1, server and client configuration, cloud OTP
- Easy multifactor authentication for SSH using YubiKey NEO tokens
- Monitoring for the cloud, part 2 - architecture
- Monitoring for the cloud, part 1 - tools and techniques
- 150 mm f/8 mirror (25 mm Pyrex) Polishing and figuring log
- How to see Sirius B
When making a telescope mirror on the machine, two parameters are important: the rotation speed of the mirror, and the rotation speed of the overarm eccentric. Other environmental parameters also matter: temperature and humidity are foremost here. To more easily monitor and display these variables, I've built an electronic device that collects this data and shows it on the control panel. This is how to build the device.
An ATtiny2313 chip, some C code, a bunch of LEDs and other components - that's your DIY Halloween decoration this year. I'll show you how to do it, and there's a video at the end of this page showing the digital creepiness in action.