ScStw/ESP32-HUB75-MatrixPanel-DMA
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Update i2s_memcalc.md

Browse source 
minor corrections
This commit is contained in:
vortigont 2021-06-11 15:02:56 +03:00 committed by GitHub
parent 944501197b
commit 85536d0884
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
doc/i2s_memcalc.md
View file

@ -20,12 +20,12 @@ And there are lot's of hogs for those:
Equalising ones with the others results in **Refresh rate**, Equalising ones with the others results in **Refresh rate**,
or (rough approximation) or (rough approximation)
<img src="https://render.githubusercontent.com/render/math?math=RefreshRate=\frac{resolution%20\times%20chain%20\times%20(ColorDepth-LSB2MSB)}{%20I%20^2S%20_%20{clock}%20}"> <img src="https://render.githubusercontent.com/render/math?math=RefreshRate=\frac{%20I%20^2S%20_%20{clock}%20}{resolution%20\times%20chain%20\times%20(ColorDepth-LSB2MSB)}">
[//]: # (github markdown does not like LaTex formulas) [//]: # (github markdown does not like LaTex formulas)
[//]: # ($$RefreshRate=\frac{resolution \times chain \times (ColorDepth-LSB2MSB)}{ I ^2S _ {clock} }$$) [//]: # ($$RefreshRate=\frac{resolution \times chain \times (ColorDepth-LSB2MSB)}{ I ^2S _ {clock} }$$)
So, how to find optimum balance for all of these? Obviously you can't change *resolution* and *chain length*, it is physical characteristics and there is not much you can do about it except cutting of your chain or pushing it to the memory limits. So, how to find optimum balance for all of these? Obviously you can't change *resolution* and *chain length*, it is physical characteristics and there is not much you can do about it except cutting off your chain or pushing it to the memory limits.
There are 3 parameters you can choose from (actually two:) There are 3 parameters you can choose from (actually two:)
- **Color Depth** - predefined at [build-time]((/doc/BuildOptions.md)) option - **Color Depth** - predefined at [build-time]((/doc/BuildOptions.md)) option
@ -34,7 +34,7 @@ There are 3 parameters you can choose from (actually two:)
- **LSB-to-MSB** transition - it can't be controlled in any way, library uses it internaly trying to balance all of the above - **LSB-to-MSB** transition - it can't be controlled in any way, library uses it internaly trying to balance all of the above
Using provided table it is possible to estimate all of the parameters before running the library. Besides calculating memory requirements it could help to find **optimum color depth** for your matrix configuration. For higher resolutions default 8 bits could be too much to sustain minimal refresh rate and avoid annoying flickering. So the library would increase MSB transition to keep the balance, thus reducing dynamic range in shadows and dark colors. As a result it is nearly almost the same as just reducing overal color depth. **But** reducing global color depth would also saves lot's of precious RAM! Using provided table it is possible to estimate all of the parameters before running the library. Besides calculating memory requirements it could help to find **optimum color depth** for your matrix configuration. For higher resolutions default 8 bits could be too much to sustain minimal refresh rate and avoid annoying flickering. So the library would increase MSB transition to keep the balance, thus reducing dynamic range in shadows and dark colors. As a result it is nearly almost the same as just reducing overal color depth. **But** reducing global color depth would also save lot's of precious RAM!
Now it's all up to you to decide :) Now it's all up to you to decide :)
/Vortigont/ /Vortigont/