Are there any affordable open source projects in the opposite direction?
I’ve built a rather complex robot with Nema steppers. Now something is messing with the control board and causing the CPU to glitch. Physically apart from the robot, the CPU board works fine for weeks. It also has a completely separate power circuit with optocouplers. So my guess is that it might be the power supply or one of the motors emitting electromagnetic interference. But how would I measure that?
colechristensen · 2h ago
First step is an oscilloscope so you can actually look at what's happening on data lines.
fxtentacle · 1h ago
I have one and the power supply lines (to the glitching CPU) seem stable with minimal noise. The CPU-integrated USB2 PHY also retains its connection even during the CPU glitch. A connected Linux workstation will not log any USB connection or disconnection events. And a CDC serial connection will remain open. The power levels to the stepper driver chips also remain stable during the glitch.
So to me, it looks like the glitching happens exclusively inside the CPU. It appears that I’m randomly experiencing the exact same issue that the PicoEMP in the original article can induce.
nicman23 · 50m ago
are you sure it is not just the nemas causing a under voltage situation?
tinix · 4h ago
you might be surprised how much you can do with a simple spark gap.
a grill lighter or modified milty zerostat can easily inject faults, albeit more manually and less precision than one of these timed devices. but it's also an order of magnitude or two cheaper...
colechristensen · 2h ago
You can also damage parts with those things just from the EMI they radiate.
dlcarrier · 4h ago
ESD protection is often overlooked in hobbyist designs. Proper shielding and routing, as well as cheap ESD protection diodes, can make a world of difference, in a products lifetime, especially in applications with inductive loads.
amelius · 2h ago
Would this pass EMC certification?
ranger_danger · 4h ago
Let's hope someone doesn't put on a bigger "antenna" on one of these and start frying electronics from a distance.
semi-extrinsic · 1h ago
Inverse square law to the rescue!
Jokes aside, I've always been curious how much you could accomplish in this direction by driving a microwave magnetron into a horn antenna using an old pulse forming network off ebay... Hell, even travelling wave tubes are getting affordable these days.
I’ve built a rather complex robot with Nema steppers. Now something is messing with the control board and causing the CPU to glitch. Physically apart from the robot, the CPU board works fine for weeks. It also has a completely separate power circuit with optocouplers. So my guess is that it might be the power supply or one of the motors emitting electromagnetic interference. But how would I measure that?
So to me, it looks like the glitching happens exclusively inside the CPU. It appears that I’m randomly experiencing the exact same issue that the PicoEMP in the original article can induce.
a grill lighter or modified milty zerostat can easily inject faults, albeit more manually and less precision than one of these timed devices. but it's also an order of magnitude or two cheaper...
Jokes aside, I've always been curious how much you could accomplish in this direction by driving a microwave magnetron into a horn antenna using an old pulse forming network off ebay... Hell, even travelling wave tubes are getting affordable these days.