Displaying 1 count

[nickknyszek]

I've made a few detectors at once, they are all having the same issue the Cosmic Watch logo appears. Once it starts it does the initial blink(1 count). The detector timer is constantly running with only showing 1 count. I've attached a BNC cable to the detector I get a solid line unlike the ones on the troubleshoot section of the instructions. When I goto plug into test point 1 or 2 I get really bad feedback. I've attached some pictures. I've also switched to an analog scope I tend to get similar patterns as to which T2 and T3 resemble however I get really bad feedback from the BNC connection. https://imgur.com/a/hkZgMeb

[mbanders]

Might be useful to show a picture of the top and bottom of your device to make sure all the resistors and soldering look ok - but the electrical-tape wrapped scintillator blocks view so maybe remove that to get it out of the way first.

[spenceraxani]

Hi,

Before looking at the test points we’ll have to make sure we get a signal from the BNC connection. Were you able to check that you have +29.5V going from the HV to GND pins on the 6-pin header? If that is the case, then next thing to check is that you are confident in the light-tightness of you taping. Perhaps wrap it in a dark cloth to see if that helps (it most likely won’t — making it light tight is normally the easier part). If you sill don’t see a signal, then there is a problem with the PCB or the SiPM.

The most common problem with the SiPM is typically that it was installed up-side down. Pin1 needs to go to the footprint with the dot on it. If you are confident in the solder job and orientation of the SiPM, then the last issue could come from a missing solder connection on the SiPM PCB. To check this simply melt and re-solidify each connection to makes sure they have good contact.

Hope this helps,

Spencer

On Jul 11, 2018, at 10:08 AM, nickknyszek notifications@github.com wrote:

h

[nickknyszek]

We saw the plus under the microscope, and originally put it on the marked with dot contact on the SiPM board. We notice we were getting a voltage drop on HV to GND of U1 pin 5 of around 13.4 volts. We then switch the polarity of the sensor and then we have 29.4 volts back. The sensor works since we are getting around a .4 output voltage. When we changed the light insensitivity to the chip voltage output from the chip changed respectively. What is your suggestion I have circled the pin on the board https://imgur.com/a/7NkSGDo that we originally had the plus at where we were getting -.4 volts.

[spenceraxani]

Hi,

Sorry for the late reply.

I don’t think I fully understand your question. Fell free to elaborate if I don’t answer it below.

The footprint you circled is pin1 on the SiPM PCB. This should be connected to pin1 on the SiPM. The SiPM is symmetric in each corner, except for one; and you will see that it simply has one extra metal leg sticking out of it. This is pin1 and should be connected to pin1 on the PCB. The other side of the footprint is pin3, and should be connected to the 29.5V to bias the SiPM.

If you are seeing strange voltages on the DC Booster, there is most likely an issue with the circuit. The most common issue I see is that one of the legs on the LT3461 is bridged with another leg. I haven’t seen 13.4V, however, since you don’t see 0 or ~5, the way we set the voltage is determined by the ratio of the resistors (226k and 10k). So if either of those is the incorrect value, you will end up with a funny voltage.

Hope this helps,

Thanks,

Spencer

On Jul 12, 2018, at 10:54 AM, nickknyszek notifications@github.com wrote:

We saw the plus under the microscope, and originally put it on the marked with dot contact on the SiPM board. We notice we were getting a voltage drop on HV to GND of U1 pin 5 of around 13.4 volts. We then switch the polarity of the sensor and then we have 29.4 volts back. The sensor works since we are getting around a .4 output voltage. When we changed the light insensitivity to the chip voltage output from the chip changed respectively. What is your suggestion I have circled the pin on the board https://imgur.com/a/7NkSGDo https://imgur.com/a/7NkSGDo that we originally had the plus at where we were getting -.4 volts.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-404561071, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu3Zo4C9gqKMf8M_eaus2ebcyczd0ks5uF3FKgaJpZM4VLU5S.

[nickknyszek]

Hello thanks for your suggestion I was able to narrow it down and fix it. Also how many counts should I be seeing, I’m at an elevation of 650 ft in Ohio. I am seeing any where from 1-10 a minute inside a building.

[spenceraxani]

Hi,

You should be seeing roughly 0.5-1.0 cps. At sea level, you should expect roughly 0.4cps due to cosmic ray muons, and the rest will likely be coming from background radiation.

Thanks,

Spencer

On Jul 18, 2018, at 10:12 AM, nickknyszek notifications@github.com wrote:

Hello thanks for your suggestion I was able to narrow it down and fix it. Also how many counts should I be seeing, I’m at an elevation of 650 ft in Ohio. I am seeing any where from 1-10 a minute inside a building.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-405966551, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu4S3xO7hEexiObcf6gsqcoIs4tHqks5uH1BIgaJpZM4VLU5S.

[nickknyszek]

Hello, So I have currently 4 detectors that all have 29.54 volts which is great. I have installed the scintillator and snensl chip correctly which is great. I’ve also re-wrapped the scintillator due to light changing the reading so currently I have no light getting into the sensor. So I plugged the 4 in and I am averaging around 3-5 counts per minute. I examine each board by a microscope which showed if there was a problem soldering etc. no problems so when I connect a detector to the oscilloscope for tp1 with Bnc connect I see the same as the instruction. For tp2 I have a lot of noise however if I set a trigger on the scope I am able to see the peaks which I see range from 500 mv-10volts I will be able see a few then goes noisy then repeats itself. But the peak typicallys stays under 3volts. I used a active source on all 4 detectors which gave strong gamma and beta rays cesium 137 if I recall not 100% sure on the source but the detectors went crazy had counts in the 100 after 30 seconds. So this told me the detectors work would my issue be with the sensitivity of the detector. I also have not calibrated the device since instructions are unclear. Would calibrating or changing the code allow the detector to pick up more pulses as a count.

[spenceraxani]

Hi,

It sounds like it could be an issue with the amplification stage. The gain at this stage is roughly 20, so I should expect your mean amplified pulse height here to be around 300mV, not 3V. Is it possible that you either have a 1k resistor in R5? or a 49.9 resistor in R3?

Also, the VCC connection on the opamp is ~4.6V, so you shouldn’t be able to get an pulses above this.

Could you send me a picture of your PCB, so I can have a look at the components? It sounds like the SiPM side is working properly.

Thanks,

Spencer

On Jul 25, 2018, at 1:14 PM, nickknyszek notifications@github.com wrote:

e ab

[nickknyszek]

So I’ve check the values and they are In the correct spot. Here is a link to my pcb board Https://imgur.com/a/gwNeqlZ Also I was getting the value for the peak on the oscilloscope and I had voltage max shown for the peak itself which was showing low mV to high V any other suggestion would be helpful thanks

[spenceraxani]

Hi,

I can’t identify any problems with the PCB — your soldering job looks pretty good. Did you add optical gel to interface the SiPM to the scintillator? This would cause a low count rate.

The calibration in the code is strictly for the electronics, so as long as you have the same components in place the calibration found in the arduino code will work. The Arduino code has a Signal_Threshold variable that determines the minimum ADC value that the detector requires before it triggers. There is also a Reset_Threshold, which sets the low ADC value before the detector begins looking for a new pulse. You could play around with these to see if maybe the threshold is causing the problem. Perhaps try bringing the Signal_threshold to 30 ADC and the reset_threshold to 20 ADC counts. With these settings I would imagine estimate that you should see about 0.3-0.4cps.

Thanks,

Spencer

On Jul 27, 2018, at 10:51 AM, nickknyszek notifications@github.com wrote:

So I’ve check the values and they are In the correct spot. Here is a link to my pcb board imgur.com/a/gwNeqlZ Also I was getting the value for the peak on the oscilloscope and I had voltage max shown for the peak itself which was showing low mV to high V

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-408460710, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu_iPDh15oa677Wj6Y-x0hiRcVl3Qks5uKzcLgaJpZM4VLU5S.

[nickknyszek]

Hello, I do have optical gel added on the SiPM, Could it be the way I've uploaded the code on the Nano? Under Programmer what does your say,"Mine says Arduino as ISP" I've changed signal and reset threshold. I've not seen anything near .3-.4 cps which would be 20 at the lowest per minute. I'm curious if the nano is bad. Thanks Nick

[spenceraxani]

Hi,

Under programmer, I have AVRISP-mkII.

If you’ve gone through all the test points, and they all look good, then the remaining issue is likely with the Arduino (or the code). I can’t really tell from your previous emails whether or not the test points look good at this point. If you see something similar to the description I troubleshooting video in https://www.youtube.com/watch?v=Ck24HGrjBfY https://www.youtube.com/watch?v=Ck24HGrjBfY (note your version has a slightly lower amplification, so TP2 and TP3 will be ~30% lower), then you know the circuit is working fine. I think it’s unlikely that the Arduino is bad, since it sounds like it is reading out the information.

Thanks,

Spencer

On Jul 30, 2018, at 8:37 AM, nickknyszek notifications@github.com wrote:

Hello, I do have optical gel added on the SiPM, Could it be the way I've uploaded the code on the Nano? Under Programmer what does your say,"Mine says Arduino as ISP" I've changed signal and reset threshold. I've not seen anything near .3-.4 cps which would be 20 at the lowest per minute. I'm curious if the nano is bad. Thanks Nick

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-408865662, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu6JE-p_ZJhkGwIPS5emxN-O7TfwBks5uLwwEgaJpZM4VLU5S.

[nickknyszek]

Do you have a python script to graph the txt file I am having problems forming graphs thanks

[spenceraxani]

Hi,

There’s an example iPython notebook located in the repository here: https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector-v2/tree/master/Recording_Data/ExamplePlots/ExampleiPythonNotebook.ipynb https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector-v2/tree/master/Recording_Data/ExamplePlots/ExampleiPythonNotebook.ipynb

It shows you how to import the txt file and make several plots.

Thanks,

Spencer

On Nov 4, 2018, at 10:52 PM, nickknyszek notifications@github.com wrote:

Do you have a python script to graph the txt file I am having problems forming graphs thanks

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-435754809, or mute the thread https://github.com/notifications/unsubscribe-auth/ABpeu-Uzb1NTbeBh70smIHZCu4iuKCUeks5ur8QagaJpZM4VLU5S.

[Joe-Miglietta]

I realize this is an old thread, but anyone having an issue with no counts registering might want to look at the applied voltage to VREF. It should be 3.3V, mine was 0V. This agreed with what I was reading from A0 = 1023 (full scale). I could see spikes on my oscilloscope indicating normal circuit behavior. With VREF = 0, then any applied voltage to A0 will read the max scale. To fix either replace the NANO or remove R17 and change the sketch code from analogReference (EXTERNAL) to analogReference (INTERNAL); You might have to also adjust SIGNAL_THRESHOLD 50 => 100 and RESET_THRESHOLD 25 => 50. After that my board started working normally.

[spenceraxani]

Hi Joe,

Interesting. The resistor R17 connects VREF to the 3.3V line from the Arduino. The 3.3V line is also used to power the temperature sensor, TMP36. I would imagine the issue you ran into is either that the temperature sensor is broken (or wrong component), or that the 3.3V voltage regulator on the Arduino is fried.

Thanks, haven’t seen this one before.

Spencer

On Feb 27, 2022, at 4:04 PM, Joe-Miglietta @.***> wrote:

I realize this is an old thread, but anyone having an issue with no counts registering might want to look at the applied voltage to VREF. It should be 3.3V, mine was 0V. This agreed with what I was reading from A0 = 1023 (full scale). I could see spikes on my oscilloscope indicating normal circuit behavior. With VREF = 0, then any applied voltage to A0 will read the max scale. To fix either replace the NANO or remove R17 and change the sketch code from analogReference (EXTERNAL) to analogReference (INTERNAL); You might have to also adjust SIGNAL_THRESHOLD 50 => 100 and RESET_THRESHOLD 25 => 50. After that my board started working normally.

— Reply to this email directly, view it on GitHub https://github.com/spenceraxani/CosmicWatch-Desktop-Muon-Detector/issues/13#issuecomment-1053680828, or unsubscribe https://github.com/notifications/unsubscribe-auth/AANF5O6YQGK2BALARYNL4LDU5KGVDANCNFSM4FJNJZJA. Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub. You are receiving this because you commented.