Broken promises

I promised I would test the new circuit after june 16th, and as I’ve promised my girlfriend to act more like a grown-up, I immediately broke this promise.

Having finished correcting exam papers ahead of time, I did a few tests this afternoon. It went terrible at first. The first 30min was spent without realising I had swapped the SH- and ICG-wires. Then ..okay I’m getting frustrated all over again just writing about it.

The long story short was that the particular nucleo board I was using had a an old and/or corrupted firmware. 2 hours later, once I figured that out, I resoldered all the resistors I had frantically been swapping, to get something resembling what ltspice said I should be getting and then:

aspirin

An aspirin blister pack covering roughly half the CCD.

fully_sat

The TCD1304 at full saturation. The ADC delivers close to it’s maximum value (4095).

darkness

“Total” darkness. (The CCD was placed upside down on the table, light is leaking in from the sides.) The pixel values are close to the dummy pixels.

20us

20µs integration

80us

80µs integration. notice the pixel values are roughly 4x higher than for 20µs.

The values for R1, R2, R3 and R4 are:

  • R1 = 1200 Ω
  • R2 = 2200 Ω
  • R3 = 1200 Ω
  • R4 = 560 Ω

in the opamp section of the circuit:

opamp-tikz

Approximately 300mV of the ADC’s range remain unused, however at this point I ran out of time and patience.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s