Yes, I know it’s bad practice. Yes I know we shouldn’t let someone ‘privilege-up’ from a normal user to root-level privs without authenticating – but sometimes we need to, and don’t just want to give them the root password (for ‘su’, for example). In Ubuntu (17.04, may work with other distros too), this can be… Continue reading Pasword-less sudo for a user
While the ESP8266’s DeepSleep mode is useful for conserving power, one ‘feature’ of it is that it resets the module. Yes, you can store things in the “RTC” (not really an RTC!) memory, as that survives the reset, I was curious to know whether millis() (the number of milliseconds since the program commenced) also survived.… Continue reading ESP8266 DeepSleep & Millis
If you’re a fan of the Wong (James: http://www.jameswong.co.uk/) you may have heard about Stevia. No, it’s not his boyfriend, it’s a type of herb that can be used as a sweetener. We got hold of some at a car boot sale the other week (50p!), and are attempting to grow it. I’m hoping to… Continue reading Stevia. Sugar or not?
The typical Arduino setup is perfect for most of my projects. Atmel’s 328p in PDIP form factor is great for makers, and TQFP provides a smaller version is size is a factor. However the 328p only has a certain amount of flash/program storage (32Kbytes), RAM (1Kbyte) and clocks at 20MHz max (although I usually use… Continue reading stm32duino “blue pill”
Making the ESP8266 “run for years on a battery” is several makers’ dream. The reality is it’s a hungry little monster, and no matter how many LiPo’s (or car batteries!) you put towards it, it’s still going to munch through them, eventually. The ESP8266 however does have a “deep sleep” mode (and other power saving… Continue reading ESP8266 and Deep Sleep
I’ve been an electronics hobbyist for years (they call these “makers” nowadays), but have always used PDIP and “normal” scale components for my work. SMD or “surface mount devices” are tiny scale components that make for easier placing by machines, smaller PCBs, less wastage (i.e. less housing) and are cheaper. But they are tiny! I’ve… Continue reading Venturing into SMD
After getting very excited by my first foray into PCB design and manufacture, I came up with a v2.0 design, still based on the original ShrimpingIt schematic. This time the board is single-layer (I wanted the routing challenge), it has a power LED (rather than one attached to the IO pins), and a reset switch.… Continue reading PCB Fabrication Version 2