Getting temperature of FLAMES Spectrometer

[joellama]

spectrometer and system information

• model: USB2000PLUS
• operating system: Ubuntu 20.10
• python version: 3.8.5
• python-seabreeze version: 1.3.0
• installed-via: pip install seabreeze

current problem

I'm trying to get the temperature of my spectrograph. When I try
from seabreeze.spectrometers import Spectrometer
spec = Spectrometer.from_serial_number()
spec.features

Temperature is listed as []. Running spec.tec_get_temperature_C() fails with a NoneType error (as expected).

I tried to follow Issue 64 that talks about pyseabreeze; however, I cannot get that to work at all because I just get a no pyusb backend error. I should add that I have installed libusb-1.0.0 and pyUSB.

So I'm at a bit of a loss, any help would be very much appreciated!

[ap--]

Hi @joellama

TEC stands for "thermo electric cooler" and the Flame-S doesn't support that feature.

As you already noticed, the code for reading temperatures on a USB2000Plus / Flame-S from #64 requires pyusb.

Are you sure you have pyusb installed? What happens if you run the following in your python interpreter:

import usb.core
usb.core.find()

Cheers,
Andreas 😃

[joellama]

Hi @ap-- ,

Thanks so much for writing back. After a bit of experimenting, I managed to get around the pyusb error by installing seabreeze with conda and not pip.

I think my issue now is how to get the temperature using the spec.f.raw_usb_bus_access.raw_usb_write functions - issue #64 I think uses different protocols that don't seem to exist in the code anymore (though again I could be wrong).

Any help would again be very much appreciated!

[ap--]

Hi @joellama

can you provide a complete code example?
Have you tried running the code in issue #64 as is? If so what's the error message?

Cheers,
Andreas

[joellama]

Hi Andreas,

Thanks for writing back and apologies for my slow delay. I tried running the code in #64; however there I cannot get past spec._dev.interface because there is no interface option listed. The available options I see are close(), f, featrues, get_serial_number(), is_open, model, open(), and serial_number.

The result of usb.core.find() is <DEVICE ID 1a40:0101 on Bus 001 Address 003>

Any thoughts?

[ap--]

Hi @joellama

I had a look, and you're right, it seems that code won't work anymore.
Try the snippet below. It's also untested (I dont have any spectrometer hardware with me right now to verify)

import seabreeze
seabreeze.use('pyseabreeze')
import seabreeze.spectrometers as sb
import struct

# open first spectrometer
spec = sb.Spectrometer.from_serial_number()

# query PCB temperature
# https://oceanoptics.com/wp-content/uploads/FlameIO.pdf, page 79f
spec.f.raw_usb_bus_access.raw_usb_write(struct.pack('<B', 0x6C), endpoint='primary_out')
raw_bytes_response = spec.f.raw_usb_bus_access.raw_usb_read(endpoint='primary_in')
temp = 0.003906 * struct.unpack("<h", raw_bytes_response[1:3])[0]  # should be 0x08 LSB MSB 

print("PCB temperature", temp)

Let me know how things go 😃

Cheers,
Andreas

[joellama]

Thank you so much @ap-- , that worked a treat! Thank you for your hard work on this project, it will be very useful for me!

[VladislavSu]

Hello @ap-- !

I'm using FLAME-NIR Spectrometer.
Is it possible to get PCB temperature via RS232 ?
If yes how can I get it?

Thanks.

[ap--]

Hello @VladislavSu,
I opened a new issue #128. Let's continue discussion there 😃