What to measure and what to think about when running secondary trigger VR on a 3.2 or 3.3
- is the correct solder jumper installed?
- SJX
- is the sectrig LM1815 pin7 adaptive threshold RC circuit soldered on fine ?
- check the schematic
- Don't forget to look for missing components, especially the 0805 resistor from LM1815pin7. 100 .. 180k is fine, or even a 0k short.
- What signal does the LM1815 output to the AVR on IC3?
- Should be a 0/5V square waveform, only 5V for a short 60usec after the input negative going edge
Make a report of your measurements. All pins.
Report reasonably please
- NEVER forget the version serialnumber history of the board
- did you make the sectrig part ? You likely forgot a part from the sectrig part. It involves only a few components, just check the sch and the components. What part connects to LM1815pin7 ? Something is in the air (with 1 pad) ?
- take pics of the LM1815 involved area
- Make a report of your measurements. All pins.
If you start to write these few things systematically, it's very likely the problem is revealed in no time. Rumbling on irc you waste much time, without result. This is very important. Reports without the most basic info, or to the wrong place is useless.
Emil's board - reply after the report requirements stressed on irc
v3.2, standard, Earlier trigged by primary trigger VR in a car.
Unfortunately v3.2 "secondary trigger (Trigg2) VR setup (with LM1815)" might miss some components ?
Can you take pics ?
GenBoard/Manual/InputTriggerHardWare "v3.3 secondary trigger=VR hardware setup " seems very clear on the setup, worths to check. 100k at LM1815pin7 (R182) is very important on v3.3, but there is no such resistor on v3.2
But why not just check all components that are involved, check the schematic ?
Miska's board
- V3.3, with auditrigger setup (complete board)
- No any reasonable output signal on output pins (pin10, 12) when input signal is applied
- Measured 100mV level from pin 12
- stays at 0V constantly, except for some noise when voltage drops in pin14
- in comparison between primary and secondary, only difference is missing output
- Input signal
- Feeding 5V logic level signal through series cap
- Measured secondary trigger input signal 900mV square wave from pin3 (-200mV to +700mV)
- Measured primary trigger input signal 970mV square wave from pin 3 (-200mV to +770mV)
- All components ok (according to sch) in visual check
- VCC (pin 8), GND (pin 2) ok
- in Pin 14, raising voltage after positive going zero-cross, falls down to 0 at negative zero-cross
- in pin 7, voltage rises when input signal is applied.
- Measured 2V level from both primary and secondary triggers with applied signal
- Repeated the tests with output disconnected (SJ7 open) and 5.4k pullup to Vcc with same results