ERROR: opc: Could not parse the firmware version from

[mc13756]

I tried to run the code and I got the following errors:

ERROR:opc:Could not parse the fimrware version from ???????????????????????????????????????????????????????????? Traceback (most recent call last): File "/home/pi/.local/lib/python3.5/site-packages/opc/init.py", line 77, in init self.firmware['version'] = int(re.findall("\d{3}", infostring)[-1]) IndexError: list index out of range

IndexError: list index out of range Traceback (most recent call last): File "/home/pi/Desktop/opc_test_3.py", line 31, in alpha = OPCN2(spi) File "/home/pi/.local/lib/python3.5/site-packages/opc/init.py", line 293, in init super(OPCN2, self).init(spi_connection, model='N2', **kwargs) File "/home/pi/.local/lib/python3.5/site-packages/opc/init.py", line 71, in init raise FirmwareVersionError(msg) opc.exceptions.FirmwareVersionError: Your firmware version could not be automatically detected. This is usually caused by bad wiring or a poor power supply. If niether of these are likely candidates, please open an issue on the GitHub repository at https://github.com/dhhagan/py-opc/issues/new. Another option would be to increase the max_cnxn_retries variable if you feel the serial communication is being held up for some reason. Can you please help me solve this? I have no idea where these errors come from

[dhhagan]

Hi @mc13756 The error comes from not being able to correctly parse the firmware version of the OPC. Often, this is caused by a wiring issue, power issue, or sometimes a code issue. Can you please let us know which version of the software you are using (opc.__version__) and post the code you used to get to this point?

[mc13756]

I am using opc.N2 firmware version 18.2 and I used the following code:

import spidev import opc spi = spidev.SpiDev() spi.open(0, 0) spi.mode = 1 spi.max_speed_hz = 500000 try: alpha = opc.OPCN2(spi) except Exception as e: print ("Startup Error: {}".format(e)) alpha.on() for key, value in alpha.histogram().items(): print ("Key: {}\tValue: {}".format(key, value)) alpha.off()

[dhhagan]

Thanks for that information. Which version of the py-opc library are you using? You can get it by issuing the command opc.__version__; you can also get it by running $pip list at the terminal and finding the version number of the package.

[mc13756]

I am using the library py-opc (1.6.0)

[dhhagan]

Thanks. How is it wired up? I assume you are using the GPIO pins? How is it being powered?

[mc13756]

Yes, I am using the GPIO pins. I give 4.6 V through an external battery. I've already checked the wiring connection and it's working fine.

[dhhagan]

Ahh okay. Have you verified the OPC-N2 will work with 4.6V? I believe it requires at least 4.8VDC and > 250 mA. You could test it by simply plugging the battery into the micro-USB slot on the OPC; it will start up by itself after a minute and log data internally. You can then grab that data via the micro-USB slot and see if it makes sense.

[mc13756]

I increased the voltage to 4.9 V with the same result. Also, I tried the following code too, in order to get the results analytically:

https://gist.github.com/dhhagan/bfb17459f0067a120f09?signup=true

Sometimes the code starts compiling and I get an error at line 83 and sometimes I have the same result as the previous code. Error: opc: Firmware version is invalid for this device.

[dhhagan]

Hmm. Can you draw the wiring diagram. It's fairly easy to mix up MISO and MOSI, so I'd like to rule that out..

[mc13756]

[metallicano]

how can i now what firmaware version am using?

[dhhagan]

Hi @metallicano; are you able to connect to the device? If so, you can use either read_information_string() or read_firmware_version().

[dhhagan]

@mc13756 This seems like a wiring issue (hopefully an easy fix!). According to this diagram, you should have the following:

• SCK -> GPIO 14, Pin 23
• SDO/MISO -> GPIO 13, Pin 21
• SDI/MOSI -> GPIO 12, Pin 19
• /SS -> GPIO 10 or 11, Pins 24, 26

If you haven't already seen this, the instructions can be found here.

Let me know if this doesn't work.

[mc13756]

I've checked the wiring and is just like you mentioned above. I run the extended version of code https://gist.github.com/dhhagan/bfb17459f0067a120f09?signup=true and I got the following error.

ERROR:opc:Firmware version is invalid for this device. Traceback (most recent call last): File "/home/pi/Desktop/opc_test_3.py", line 31, in alpha = OPCN2(spi) File "/home/pi/.local/lib/python3.5/site-packages/opc/init.py", line 301, in init raise FirmwareVersionError("Your firmware is not yet supported. Only versions 14-18 are currently supported.") opc.exceptions.FirmwareVersionError: Your firmware is not yet supported. Only versions 14-18 are currently supported

Also, when I tried to install py-opc by typing: pip install py-opc [--upgrade] in a terminal I got: "Invalid requirement: '[--upgrade]' so I've installed it by typing only: pip install py-opc

[dhhagan]

@mc13756 Try pip install py-opc --upgrade - the brackets are just to indicate it is optional

[mc13756]

ok. thank you. It seems like OPC works randomly. Sometimes I got the following error:

ERROR:opc:Firmware version is invalid for this device. Traceback (most recent call last): File "/home/pi/Desktop/opc_test_3.py", line 31, in alpha = OPCN2(spi) File "/home/pi/.local/lib/python3.5/site-packages/opc/init.py", line 301, in init raise FirmwareVersionError("Your firmware is not yet supported. Only versions 14-18 are currently supported.") opc.exceptions.FirmwareVersionError: Your firmware is not yet supported. Only versions 14-18 are currently supported

Sometimes the code runs normally and I got numbers every 10 seconds, and some other times it looks like it runs ok but I got only zeros. In this case the OPC's fan isn't working and I get false on turning ON or OFF the opc.

Turning on the opc ON: False

or

Turning off the opc OFF: False

[dhhagan]

@mc13756 Interesting - the script your using is pretty outdated (from 2015, I think). I would take a look at the most up-to-date docs for reference. When did you buy the OPC and do you have the SPI-USB connector for debugging purposes? Your OPC is most likely v18.2, but I can't be sure..

[mc13756]

I think we bought the OPC on 2015 and our version is 18.2. Yes, I have the SPI-USB connentor

[dhhagan]

@mc13756 Could you try using the SPI-USB connector and then using the library utilizing pyusbiss just to check to make sure it's working? Or even use the Alphasense software to double check? I still think there is a poor connection somewhere or something like that. Maybe @DancingQuanta has some ideas?

[metallicano]

hi , the problem persist , but in the end of the text i have this : your firmware is not supported :C

[metallicano]

now the code runs but sometimes XD,

[dhhagan]

@metallicano Can you post the code and wiring you're using?

[metallicano]

import spidev import opc from time import sleep

spi = spidev.SpiDev() spi.open(0, 0) spi.mode = 1 spi.max_speed_hz = 500000

alphasense = opc.OPCN2(spi) alphasense.on() sleep(1) print (alphasense.read_info_string()) print (alphasense.histogram()) alphasense.off()

[metallicano]

the wiring is the same : SCK -> GPIO 14, Pin 23 SDO/MISO -> GPIO 13, Pin 21 SDI/MOSI -> GPIO 12, Pin 19 /SS -> GPIO 10 or 11, Pins 24, 26

[metallicano]

hi , problem solved , thanks for all 💯

[mc13756]

Hello! @dhhagan I changed my breadboard connection with a more stable wiring method and the firmware version error doesn't appear any more. At least for now... The code runs normally. Is it normal to get decimal numbers? I was waiting to see integers, considering that OPC counts particles.

[DancingQuanta]

The decimals could be an average. Can you show the data you are getting please?

[dhhagan]

Hey @mc13756 The reason you are getting decimals is because the default argument for number_concentration is True (read more about it in the docs). Thus, the number concentration in units of #/cc is being returned rather than the raw count. If you want the raw count, simply set number_concentration=False.

[mc13756]

How can I get access to change the number_concentration to False?

[dhhagan]

@mc13756 It's just an argument to opc.histogram(). So if you wanted to return the values as a raw histogram, you would do opc.histogram(False) or opc.histogram(number_concentration=False).

[mc13756]

I changed the argument to False and everything looks to work normally.

Thank you very much!!!

[dhhagan]

Good to hear, @mc13756: just be aware that the number you are seeing is the total number of particles in each bin since the last time you called either pm() or histogram(). In doing the conversion to #/cc, I was accounting for the sampling time and flow rate.