digispark pro first impressions

Hey, so the digispark pros arrived: the board is quite impressive as it’s only slightly larger than the original digispark … it is packed with many nice hardware features: SPI, i2c, pwm … and loads of it (compared to it’s size) the RGB LEDs worked out of the box one of my two RF24 shields… Read More »

grbl shields

So, i have a single layer grbl shield and a dual layer grbl control shield for a leonardo on my desk. grbl shield: single top-layer (the silver one) i2c connector (bottom right) axis/stepper connectors (top right) limits connector (top center) depth sensor connector (top left) 3 switches for reset/start/stop status LED spindle control shield: dual… Read More »

Pololu/A-Star bootloader on Arduino Leonardo

The 32U4 based Arduino-Micros and Leonardos do an 8 second delay for the bootloader. This is way too long to work with a esc – the esc will give up saying: no valid servo signal detected – security shutdown. Pololu’s A-Star family is using a different bootloader that boots into the application in ~1s and… Read More »

PCB designs for grbl

‘ve been working on PCB designs for my grbl setup: main controller spindle controller stepstick adapter for NEMA23 stepper I’ have them produced asap … Update: some grbl_mc PCBs should arrive end of next week. 2 of them might be available for sale (including the TBX…). please email if interested. an earlier version of the… Read More »

grbl_mc – spindle & machine control on arduino micro/Leonardo

So, spindle and cooling control with a lcd is working: connects to grbl via i2c has 15-bits of rpm: 0-32767rpm (Sx, M3/M4/M5) flood&mist cooling (M7/M8/M9) tool select (Tx) tool change (M6) display a message (currently grbl build/version and tool parameters on m6 tool change) closed loop rpm control (PID, untested) Spindle is set @ 400rpm… Read More »

arduino _delay uses a timer!

Be sure to be aware of “hidden” dependencies on AVR hardware! The arduino GLCD lib (build 442) does use _delay( ms) (and therefore “timer0“) for it’s initial setup – and never after. If you’re trying to use timer0 for your own purposes – make sure you GLCD.Init(); first. After the display is set up, you… Read More »

Raspberry Pi Hardware Watchdog …

Our Qt Digital Signage software is run from init.d. It runs on EGLFS, so no X involved. It also opens /dev/watchdog, sets a 15sec timeout and tickles it via a QTimer set to 4800ms – 3 ticks per timeout should be plenty. During boot, the system is so busy that my app misses the 15secs… Read More »

spindle & cooling controller for grbl

So, spindle and cooling control with a lcd is coming up: connect to grbl via i2c 15-bits of rpm flood&mist cooling tool select (Tx) and tool change (M6) display a message (not yet integrated in grbl) It’s using a simple 1/2-byte protocol. UPDATE: Closed loop rpm control is working. Spindle is -off-. The servo pwm… Read More »

Debugging with the new Atmel ICE

Atmel has a new version of their “budget” ICE available. It comes in three flavours: “bare” PCB, “basic” Case + simple cable, Case + multiple adapters. It seems to support any protocol you might have heard of … I got the basic version for around EU47 – not too bad. It comes with a micro… Read More »