4 ms·

some bread (such as dark rye) has the same colour as toast.

by timb 18y ago

wwalker3 18y ago
Good point. You'd have to make the darkness control an offset from the initial darkness, rather than an absolute darkness level. Not hard, but you'd need an extra bit of analog circuitry to store the initial value of the toast's reflectance.
- maximilian 18y ago
  You could also not waste time figuring out how to store the darkness using "analog circuitry" and just put a micro on the thing. Then you could have multiple sensors that would figure out what kind of bread was put in and then toast accordingly. It would a pretty fun problem to work on once the basic toaster was finished. You could play around with different kinds of sensors - heat, infrared LEDs+detectors, normal LEDs+detector, just light detector from ambient of the coils. And the best part would be that you get to eat piles of yummy toast.
- blogimus 18y ago
  considering the parent's post about breads such as dark rye (pumpernickel): These breads are dark enough to start that there is 1) less gradation between untoasted and burnt than say, white or wheat bread, so the same "delta dark" would results in burnt toast. 2) the toast can (if the original bread is dry and/or dense enough) become unpalatably hard during the toasting process even before turning dark enough to be considered burnt.
  - wwalker3 18y ago
    Another strategy I considered was using an infrared photodiode instead of a visible light photodiode. That way, the diode effectively reads the toast temperature rather than color, which would address the issues you mention. But I was a bit worried that the infrared emission of the heating coils would swamp that of the toast. For my original design, you'd definitely have to set the control to only slightly darker than your rye bread, or you'd get burned rye toast.
    - demallien 18y ago
      Well, I reckon that charred toast is around about the same colour regardless of the original bread - charcoal is charcoal. So, what you need to do is take the initial colour, subtract that from 'burnt toast', and then divide the result into the 16 desired intervals... For those of us that have discovered the joy of slightly burnt toast with Vegemite for breakfast, accompagnied by a strong coffee, the value 15 will be seeing heavy use :-) Of course, I'm interested to hear how you're going to go about solving the non-uniformity of toasting problem - sometimes part of my toast is still white when other parts are black!
      - wwalker3 18y ago
        The only elegant way I can think of to solve the toasting non-uniformity problem requires a breakthrough in materials science. If you could make the toaster's heating coils out of a substance that increases its resistance with increased light influx, then the bright areas of the toast would increase the coil resistance nearby, thereby producing more heat locally and tending to even out the toast. Of course, this is probably a lot of work just to make a toaster.

some bread (such as dark rye) has the same colour as toast.

by timb 18y ago

some bread (such as dark rye) has the same colour as toast.

Good point. You'd have to make the darkness control an offset from the initial darkness, rather than an absolute darkness level. Not hard, but you'd need an extra bit of analog circuitry to store the initial value of the toast's reflectance.

maximilian 18y ago
You could also not waste time figuring out how to store the darkness using "analog circuitry" and just put a micro on the thing. Then you could have multiple sensors that would figure out what kind of bread was put in and then toast accordingly. It would a pretty fun problem to work on once the basic toaster was finished. You could play around with different kinds of sensors - heat, infrared LEDs+detectors, normal LEDs+detector, just light detector from ambient of the coils. And the best part would be that you get to eat piles of yummy toast.
blogimus 18y ago
considering the parent's post about breads such as dark rye (pumpernickel): These breads are dark enough to start that there is 1) less gradation between untoasted and burnt than say, white or wheat bread, so the same "delta dark" would results in burnt toast. 2) the toast can (if the original bread is dry and/or dense enough) become unpalatably hard during the toasting process even before turning dark enough to be considered burnt.
- wwalker3 18y ago
  Another strategy I considered was using an infrared photodiode instead of a visible light photodiode. That way, the diode effectively reads the toast temperature rather than color, which would address the issues you mention. But I was a bit worried that the infrared emission of the heating coils would swamp that of the toast. For my original design, you'd definitely have to set the control to only slightly darker than your rye bread, or you'd get burned rye toast.
  - demallien 18y ago
    Well, I reckon that charred toast is around about the same colour regardless of the original bread - charcoal is charcoal. So, what you need to do is take the initial colour, subtract that from 'burnt toast', and then divide the result into the 16 desired intervals... For those of us that have discovered the joy of slightly burnt toast with Vegemite for breakfast, accompagnied by a strong coffee, the value 15 will be seeing heavy use :-) Of course, I'm interested to hear how you're going to go about solving the non-uniformity of toasting problem - sometimes part of my toast is still white when other parts are black!
    - wwalker3 18y ago
      The only elegant way I can think of to solve the toasting non-uniformity problem requires a breakthrough in materials science. If you could make the toaster's heating coils out of a substance that increases its resistance with increased light influx, then the bright areas of the toast would increase the coil resistance nearby, thereby producing more heat locally and tending to even out the toast. Of course, this is probably a lot of work just to make a toaster.