They should have first attempted going without VCC and GND. Just make sure CS# is hooked to ground and WP is hooked to VCC.
Both pads would have protection diodes to VCC/GND providing phantom power when tied to the appropriate rail. Plenty of chips work fine with phantom power.
That's a cool idea. Going to file that away for another time. I imagine you'd maybe run your phantom voltage a little higher to overcome the ESD diode drop?
Interesting use of a salt solution to weep into the broken parts to make contact. I personally would be shitting diamonds if I was reduced to this, it seems like it would be way too easy to short out the board with this method, especially when the packaging is so badly mangled.
I probably would have tried slowly and carefully whittling away the plastic near where the bond wires used to be to try to expose some metal first before using this salt water bath idea, but if it works it works.
> the rocket dropped unchecked and burried [sic] itself 3 meters underground.
Very impressive! I wonder at what speed it impacted. I tried reading the chart at the bottom but I'm not sure what "axial" velocity is—probably not vertical speed given it drops over time rather than rises as the rocket dropped.
I suppose you could take the derivative of the height at impact point but I'm too lazy.
The red line is axial acceleration. The rocket rapidly slows to terminal velocity, reaching it at about 25 sec., then continues to slowly decelerate as t.v. decreases as the air gets thicker. [edit: *] The black line is estimated velocity, as integration of the acceleration. It gives up trying to calculate that at about 45 sec. Based on the barometer readings, it looks like it was going about 650 fps at impact.
What I find interesting is the 4-second delay before igniting the second stage. This is very inefficient compared to immediately igniting it when the first stage burns out. Max-Q (airspeed pressure) issues? 30,000 ft permit ceiling?
Edit: * At 25 sec. it's still going up, so the velocity is decreasing due mainly to gravity, but the rocket is ballistic so the accelerometer is slightly negative due to air friction adding to the gravity deceleration. At about 40 sec. it has reached max altitude and velocity is zero. Accelerometer is still close to zero. Velocity picks up, as shown by barometric altitude curve. Eyeballing it, at about 65 sec. its reached terminal velocity, as shown by barometer curve being pretty flat. Decrease after that is due to decreasing t.v.
russdill|1 year ago
Both pads would have protection diodes to VCC/GND providing phantom power when tied to the appropriate rail. Plenty of chips work fine with phantom power.
0_____0|1 year ago
jandrese|1 year ago
I probably would have tried slowly and carefully whittling away the plastic near where the bond wires used to be to try to expose some metal first before using this salt water bath idea, but if it works it works.
0_____0|1 year ago
racked|1 year ago
Reminds me of PCBite
russdill|1 year ago
PittleyDunkin|1 year ago
Very impressive! I wonder at what speed it impacted. I tried reading the chart at the bottom but I'm not sure what "axial" velocity is—probably not vertical speed given it drops over time rather than rises as the rocket dropped.
I suppose you could take the derivative of the height at impact point but I'm too lazy.
mgsouth|1 year ago
What I find interesting is the 4-second delay before igniting the second stage. This is very inefficient compared to immediately igniting it when the first stage burns out. Max-Q (airspeed pressure) issues? 30,000 ft permit ceiling?
Edit: * At 25 sec. it's still going up, so the velocity is decreasing due mainly to gravity, but the rocket is ballistic so the accelerometer is slightly negative due to air friction adding to the gravity deceleration. At about 40 sec. it has reached max altitude and velocity is zero. Accelerometer is still close to zero. Velocity picks up, as shown by barometric altitude curve. Eyeballing it, at about 65 sec. its reached terminal velocity, as shown by barometer curve being pretty flat. Decrease after that is due to decreasing t.v.
two_handfuls|1 year ago
wildekek|1 year ago
aaron695|1 year ago
[deleted]
polishdude20|1 year ago