#avr Logs

Jul 10 2020

07:38 AM mouseghost: do u use like, a separate driver for a stepper?
07:44 AM mouseghost: or just slap a darlington pair?
07:50 AM cehteh: depends on what you want to do
07:50 AM cehteh: tiny/simple steppers some with ULN2003 as driver
07:50 AM cehteh: for small currents and moderate speeds thats ok
07:50 AM cehteh: when you need advanced features like microstepping, fast speeds, current reduction on idle etc then you need something better
07:50 AM mouseghost: i see, thanks
07:59 AM cehteh: mouseghost: for that combination yes, and at max speed it has almost zero power, can be stopped with a light touch
08:00 AM mouseghost: ohm .-.
08:00 AM cehteh: but these steppers are really punny, including the driver board you get them for 1Eur
08:00 AM cehteh: and not meant for such speeds
08:01 AM mouseghost: also lol i just found a wire that i wanted :|
08:01 AM mouseghost: i see
08:02 AM mouseghost: well, im not talking about drone kind of things ;x
08:03 AM cehteh: hehe thats not for drone, i just did a test and needed something to put on the axle
08:05 AM mouseghost: also, one drives them with a pwm, right? 1 pulse is 1 step as i understand?
08:05 AM mouseghost: that fan kinda looks like on one of these big wind generators in the fields
08:08 AM cehteh: it a small propeller for a drone :)
08:08 AM cehteh: but i was only testing the stepper driver
08:08 AM mouseghost: ahmm
08:09 AM cehteh: and when you want to drive the steppers directly you need to energize the windings in in some special order
08:10 AM cehteh: for drones which use bldc motors .. they need special controllers, slightly similar to steppers but they dont do stepping
08:12 AM cehteh: you would need pwm when you want to control the current or shape the waveform you send to the stepper (microstepping) but thats really going to be complicated
08:25 AM mouseghost: ;-;
08:46 AM twnqx: my recent contact with stepper driver lead to a burn, on a decent pcb excessively designed for cooling ;_;
08:48 AM twnqx: as in, 4 layers of ground, 2oz copper instead of the usual 1oz, dozens of vias for thermal conducting, pure gold backside with no solder resist, mounted with thermal foil on a heatsink >_>
08:58 AM mouseghost: "on sale: stepper motor bbq"
10:47 AM twnqx: meh, designing products to pass SI, ESD and EMI is more difficult than anticipated for connectors
04:08 PM Evidlo: Does the atmega32u4 non RC version come with the bootloader enabled by default?
04:09 PM Evidlo: i.e. can I take fresh chips from Microchip and program them over USB without an ISP programmer?
04:22 PM markasoftware: i don't think so?
04:23 PM markasoftware: actually https://www.eevblog.com/forum/microcontrollers/atmega32u4-bootloaders-hwb-pin-usb-programming/msg1088263/?PHPSESSID=9ffg265sblp3f9u44taf4obr93#msg1088263 suggests that it does
04:29 PM cehteh: yeah iirc the usb ones come with usb bootlader preflashed
11:42 PM day_ is now known as day