Commit f1f0aa51 authored by Jake Read's avatar Jake Read
Browse files

add doc from wakeup struggle

parent 5e517be0
......@@ -6,3 +6,42 @@ Board out, tested design with other micros.
## Notes for Next Run
OK: these are kind of ugly on the motors, hanging way out. A motor also gets pretty hot even at 1a, which will be problematic for plastics. To cobat, design a new circuit alongside the fan design. Bolt with longbois, this is no problem. You can shift the position of the circuit-stackup so that you can use all four longbois (or two at diagonal?) and use that offset space (overhanging the motor now) to mount the fan, which can blow 1/2 over the motor body, 1/2 under the fets.
## Notes from Debugging
after some time trying to debug, I'm still stuck. I've implemented my SPI line a-la the example above,
which I have known to work. I have double checked through the tmc262 datasheet and confirmed with
my logic probe that the SPI setting are all correct
I was initially not receiving anything back from the driver, but am now. to confirm, I pad the
20-23 bits in my 3-byte word (the tmc only taking 20 of these) with a 1101 pattern -> these should shift
out of the tmc after the 20th bit, which they do.
as I turned the voltage up, I started hearing a ticking, at around the hz I am continually updating
the driver's spi with (or trying to). on inspection, this sounds like it's originating from the driver
and - this thing gets hot. and - I find a '1' in the OTPW: over temperature warning bit (response)
this leads me to believe that I am probably having a circuit problem, but I cannot for the life of me
sort it out
the heat comes on as soon as power is applied, so that's a clue
the logic in the chip obviously works, it replies to SPI writes,
but it seems likely that something else is fried.
the heat comes on with a motor unplugged or not
so far this is reproducable on two of these circuits, I'll test more ... ok, three
ok, some struggle here. I pulled the TMC262 chips off to pin-test outputs, and found that these were
the circuits I had earlier with the soldermask error from the fab: two gnd pins and the only v+ pin
to the tmc were covered. this was my bad: when I asked ruben to make more steppers, he used the
old circuits that I hadn't thrown out. should have thrown them out, should have shown ruben the right ones.
fixed this by scratching the pads off and re-soldering. then had a fun power-supplies and bfc's moment
watching the motor pull the benchtop supply (0-30v, 0-3a) down from 24v to 8v (the tmc's threshold) at startup
this was about a 5ms event. this means I need more bulk capacitance on this board ! I fixed that by bringing
some of my BFC boards in line with the psu, now things are nice and smooth
to debug, I used my logic analyzer and set up to read binary back, then just double checked against the datasheet really carefully, and set up the analyzer according to the datasheet (for cpol and cpha)
......@@ -107,7 +107,7 @@ Sheet="1"
Type="Board Editor"
View="-1.77084 -37.8244 77.7259 37.0933"
View="34.5155 -8.85171 53.0039 8.57176"
WireWidths=" 0.15 0.6096 2.54 0.4064 0.0762 0.3048 0.508 0.8128 0.2 2.032 1.27 1.016 0.254 0.2032 0.1016 0.1524"
PadDiameters=" 0.254 0.3048 0.4064 0.6096 0.8128 1.016 1.27 1.4224 1.6764 1.778 1.9304 2.1844 2.54 3.81 6.4516 0"
PadDrills=" 0.25 0.35 0.4 0.45 0.5 0.55 0.65 0.7 0.75 0.8 0.85 0.9 1 0.6 0.3 2.2"
......@@ -145,7 +145,7 @@ SwapLevel=0
Type="Control Panel"
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