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  1. BGB

    Current limiting strategies for L298N?...

    ADD2 (seems I can no longer edit the prior post): here are some RMSE results: Const DPWM Err: Avg=4.9489 Min=0.0000 Max=5.4065 Const PDM8 Err: Avg=10.8478 Min=0.0000 Max=27.8420 Const PDM12 Err: Avg=5.7890 Min=0.0000 Max=10.6192 Sin DPWM Err: Avg=10.9892 Min=4.7250 Max=85.7736 Sin PDM8 Err...
  2. BGB

    Current limiting strategies for L298N?...

    or, maybe a Raspberry Pi + an Arduino. then the Arduino can be left for motor control, with the Raspberry Pi mostly for running application code. or maybe a Beagle Bone Black or similar... (more expensive than an RPi by itself, but price competitive with an RPi+Arduino). but, yeah, running...
  3. BGB

    Current limiting strategies for L298N?...

    yeah. some of it is for special use-cases. like there are times when things don't exactly fit all that well with the standard "compile directly to native code" approach of typical compilers, ... for example, in its current incarnation, the C compiler compiles to an intermediate 3-address-code...
  4. BGB

    Current limiting strategies for L298N?...

    my confidence is a bit lacking sometimes, as I don't have a whole lot to show for my time. I have actually written some compilers and VMs as well, which is where a lot of the ASM goes. most of my ASM experience has been for x86 in 32 and 64-bit modes, some past experience with 16-bit. also have...
  5. BGB

    Current limiting strategies for L298N?...

    limit and wait for manual intervention? maybe also turn on a LED and send back a signal? (then software can initiate an emergency shutdown if this was unexpected?) I am not really all that young anymore, more like, basically just a loser. never got a job, never moved out, don't have a GF...
  6. BGB

    Current limiting strategies for L298N?...

    yeah. cost was a partial deciding factor, along with having sufficient output current, and giving reasonably direct control over the motors' behavior. makes sense. rated input voltages are 7.5V to 46V. none of the diagrams I see show current-limiting on the motor side though (though, most...
  7. BGB

    Current limiting strategies for L298N?...

    possible, but: I already have the L298N chips here (the order showed up); those drivers listed there are generally significantly more expensive. as-in, any good options under around $4 per stepper motor or so? (well, and also don't want to order anything more right now). not current limiting...
  8. BGB

    Current limiting strategies for L298N?...

    well, here is the issue: I am building a project (a small CNC milling machine), and for the steppers am going to be using some L298N chips. these will be driven from a Raspberry Pi, possibly with step-up transistors (data sheet seems to imply it is intended to be driven with 5v 30mA signals...
  9. BGB

    new here, H-bridge frustrations...

    yeah. when I measured it earlier, I was getting around 5v for a 7v input. if it is 10v or 11v for a 12v input, probably good enough... didn't get around to trying to use it to spin up the stepper yet, but by pulsing the pins, the stepper did move slightly, and when powered up in a single state...
  10. BGB

    new here, H-bridge frustrations...

    in other news: got around to wiring up the transistors with the emitters connected together (like in the first reply), seemed to work pretty good, at least in the initial tests (need more testing). testing with 7v, got +/- 5v output. no obvious significant current leaks. for example...
  11. BGB

    new here, H-bridge frustrations...

    I meant being fed into the motor. if I set a variable power supply to a low voltage, but have a higher amperage, it spins pretty hard, but is slower. if it is set to a higher voltage, but the amperage limit is low, it spins fast but is easily stalled.granted, yes, the motor does drop the...
  12. BGB

    new here, H-bridge frustrations...

    I had noticed an effect like this before, namely that it would be stable at a lower voltage, but current would jump up when voltage was increased. I fiddled with the resistors for a while until I got it stable at 12v. could be. I had wanted maximum motor power, but this seems to depend more on...
  13. BGB

    new here, H-bridge frustrations...

    the circuit with the collectors connected together: yeah, I had to add the extra resistors to keep the transistors off, otherwise, they would turn on by themselves and dump current, I had suspected conduction between the transistor bases, as current flow would stop whenever the connection...
  14. BGB

    new here, H-bridge frustrations...

    I have some integrated drivers (L298N) ordered (just waiting for them to show up), these will probably be used for the steppers. also, for low-power uses, also have some L293D drivers ordered. ok, I had tried an arrangement like above in the past, although I had used the transistors on the...
  15. BGB

    new here, H-bridge frustrations...

    ok, I am new here... and, I am relatively new to electronics as well (my main thing is mostly programming, but I have been messing a bit with electronics over the past several months). but, one thing I have noticed is an annoyance with trying to build H-bridges which work well... in...
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