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jansonntag:attempt3
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jansonntag:attempt3 [2021/02/08 10:39] jan |
jansonntag:attempt3 [2021/03/13 13:57] jan |
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| - | ====== Analog Cherry Keyboard Attempt 3 (WIP) ====== | + | ====== Analog Cherry Keyboard Attempt 3 ====== |
| After a while of looking at it, this seems far too complicated! There have to be simpler, cheaper, and more accurate solutions. I started searching for some ICs that maybe can do the trick but didn't found any good other than the links I posted above. But then Henrik found something great: The LDC1314 | After a while of looking at it, this seems far too complicated! There have to be simpler, cheaper, and more accurate solutions. I started searching for some ICs that maybe can do the trick but didn't found any good other than the links I posted above. But then Henrik found something great: The LDC1314 | ||
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| Let's go through this code step by step: | Let's go through this code step by step: | ||
| - Import the library and the Wire library (I2C) | - Import the library and the Wire library (I2C) | ||
| - | - Then instantiate an LDC131X Object (the false means now alternative address) | + | - Then instantiate an LDC131X Object (the false means no alternative address) |
| - The lastTen and pointer variables are needed later to calculate an average of 10 measurements | - The lastTen and pointer variables are needed later to calculate an average of 10 measurements | ||
| - The setup starts with initiating the Wire and Serial communication | - The setup starts with initiating the Wire and Serial communication | ||
| Line 186: | Line 186: | ||
| As you may have seen I set the LDC to not use the external oscillator I put on the PCB. This is because I miss understood the reason for this pin to exist. It´s an alternative to the internal oscillator. I thought I would have to put in the value I calculated for ƒSENSOR in Webench. That's why I have a 6Mhz input now. This is not needed! The LDC will compare the oscillating frequency that comes back from the coil (this is the 6MHz I calculated) with the internal oscillator (40 MHz) or a given external oscillator. But the oscillating frequency should be greater than 4 x 6MHz. Because this isn't the case with the one I got, I´m just using the internal one. This works so the external one does not have to be populated on the PCB. This also saves in cost on the final PCB. I hope this was understandable. | As you may have seen I set the LDC to not use the external oscillator I put on the PCB. This is because I miss understood the reason for this pin to exist. It´s an alternative to the internal oscillator. I thought I would have to put in the value I calculated for ƒSENSOR in Webench. That's why I have a 6Mhz input now. This is not needed! The LDC will compare the oscillating frequency that comes back from the coil (this is the 6MHz I calculated) with the internal oscillator (40 MHz) or a given external oscillator. But the oscillating frequency should be greater than 4 x 6MHz. Because this isn't the case with the one I got, I´m just using the internal one. This works so the external one does not have to be populated on the PCB. This also saves in cost on the final PCB. I hope this was understandable. | ||
| - | Here you can see both the board and the plotter in action: | + | Here you can see both the board and the plotter in action |
| - | {{: | + | {{: |
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| + | As you may see the graph shows when the button is pressed and how far it is pressed. But the result is not very accurate and there is a lot of interference. This is because of the high gain I set. But otherwise, there wouldn' | ||
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| + | So there will be an attempt 4. There I will test out the bigger brother of the LDC1314: The LDC1614. It has the same pinout and overall package, so it will be an in-place replacement. The big advantage is the 28-bit resolution. Hopefully, there is no gain needed then. | ||
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| + | \\ | ||
| + | [[JanSonntag: | ||
jansonntag/attempt3.txt · Last modified: 2021/03/24 17:10 by jan
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