#robotics Logs

May 30 2017

12:10 AM rue_shop3: I got stm32 serial working!!!!
12:13 AM rue_shop3: yay!
12:13 AM rue_shop3: tx anyhow
12:20 AM rue_house: oooh I know what got me on stm32 timers
12:20 AM rue_house: the goal to make a servo controller
01:02 AM rue_house: timer1 on the stm32 has an incremental encoder interface
01:03 AM rue_house: 'Supports incremental (quadrature) encoder and hall-sensor circuitry for positioning purposes'
01:03 AM rue_house: ooh my, the main counter value can be controlled by an encoder
01:04 AM rue_house: which means you can still use the compare registers against it
01:12 AM rue_house: wow
01:13 AM rue_house: uh, looks like you can hardare chain timers to set each other off
01:13 AM rue_house: so setting up a high resolution servo pwm system would be easy
01:14 AM rue_bed: futhermore It could be changed to the dma to split the pulses to different io pins
01:15 AM rue_bed: so, using 3 internal systems and you have completely hardware servo pwm for 16 channels
01:15 AM rue_bed: with the microcontroller twiddling its thumbs
01:15 AM rue_bed: (and taking some serial commands)
01:51 AM anonnumberanon: Hi is this too computationally intensive for the task? https://ideone.com/9j8wQC
02:19 AM anonnumberanon: got it
04:15 AM Jak_o_Shadows: Tom_L: did you get a F4 fort cheap?
04:16 AM Jak_o_Shadows: They have DCMI for camera, so I'm tempted to get one.
04:16 AM Jak_o_Shadows: Nice rue! Did you get serial working?
04:16 AM ryokobazooka is now known as badabigboom
04:54 AM Tom_L: free
06:13 AM Jak_o_Shadows: ah
08:30 AM rue_bed: Jak_o_Shadows, yes
09:25 AM rue_house: I think the timer on this stm32 can count up, down, and sideways
09:33 AM z64555: never heard of a sideways counter
09:35 AM SpeedEvil: bit reversed?
09:36 AM SpeedEvil: Or you could make arguments for counters which can do motor-controlly things, with real and imaginary
09:37 AM rue_house: hah, the lesser timers support enocders too
09:37 AM rue_house: so, it looks like every timer on a stm32 can be used to track an incremental encoder
09:38 AM rue_house: tho I'm lost trying to set up a prescaler!
09:40 AM z64555: should be just a prescale register...
09:40 AM rue_house: fed by?
09:41 AM z64555: fed by what? you just set the register and go
09:41 AM z64555: at least that's what I'm used to on other chips
09:41 AM rue_house: I dont think I know enough to do anymore than just an initial guess of the source clock rate
09:42 AM rue_house: the only thing I know is that the libopencm3 got the serial baud rate right
09:44 AM rue_house: it seems I know the gpio clock rates, I dont know if the timers are down or beside those
09:46 AM rue_house: it looks like the timers have a one-shot mode
09:48 AM rue_house: the first goal is to get an interrupt at 50Hz
09:51 AM rue_house: not sure what timer to use tho, looks like I should use 2-5
09:51 AM rue_house: on this chip I ahve a 2 and a 3
06:54 PM SOLOL is now known as solol
08:30 PM _Sol_ is now known as Solgriffin