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notes_8a.md

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LED Badge

Speed = 8,000,000
Target Frame Rate = 30

Segments = 12
Pixels per Segment = 36
Brightness Passes = 8 # this is with the 1, 4, 8 gamma spread

Frame Width = 36
Frame Height = 12
Pixels = Frame Width * Frame Height => 432
Pixel Blocks = floor((Frame Width + 7) / 8) * Frame Height => 60
Padded Pixels = Pixel Blocks * 8 => 480

Bits per Pixel Compressed = 2 bits
Bits per Pixel Uncompressed = 3 bits
Pixels per Byte Compressed = 8 bits / Bits per Pixel Compressed  => 4
Pixels per Byte Uncompressed = 8 bits / Bits per Pixel Uncompressed => 2.6667

Bytes per Frame Compressed = Pixels / Pixels per Byte Compressed in bytes => 108 bytes
Bytes per Frame Uncompressed = Pixels / Pixels per Byte Uncompressed in bytes => 162 bytes

Measured Segment Cycles = 259 # measured
Refresh Interval = 352
Refresh Rate = Speed / Refresh Interval / Segments / Brightness Passes => 236.7424

Cycles Left Over = Speed * ((Refresh Interval - Measured Segment Cycles) / Refresh Interval) => 2,113,636.3636
Cycles per Frame = Cycles Left Over / Target Frame Rate => 70,454.5455
Cycles per Pixel = Cycles per Frame / Pixels => 163.0892
Cycle Ratio = Cycles Left Over / Speed => 0.2642

Measured SetPixBlock Cycles = 35
Measured GetPixBlock Cycles = 31
Measured ClearBuffer Cycles = 908
Measured SolidFill Cycles = 1921
Measured Fill Cycles = 5754
Measured Copy Cycles = 2094

Est Cycles per Fill = Pixel Blocks * Measured SetPixBlock Cycles => 2,100
Est Cycles per Copy = Pixel Blocks * (Measured GetPixBlock Cycles + Measured SetPixBlock Cycles) => 3,960

Est Longest Op = Measured Fill Cycles / Cycle Ratio => 21,778.5806
Fills per Frame = Cycles per Frame / Measured Fill Cycles => 12.2444
Copies per Frame = Cycles per Frame / Measured Copy Cycles => 33.6459

Bandwidth

Video Bandwidth = Target Frame Rate * Bytes per Frame Compressed => 3,240 bytes
Command Bandwidth = Target Frame Rate * 6 in bytes => 180 bytes
Bandwidth = Video Bandwidth + Command Bandwidth => 3,420 bytes
Bits Per Baud = 1 + 8 + 1
Min Baud = Bandwidth * (Bits Per Baud / 8) / sec in baud => 34,200 baud
Baud = 38400

Bytes per Frame = (Baud / Bits Per Baud) / Target Frame Rate => 128
Cycles per Byte = Speed / (Baud / Bits Per Baud) => 2,083.3333
Queue Size = Est Longest Op / Cycles per Byte => 10.4537

UBBR(Baud) = Speed / (16 * Baud) - 1
Selected UBBR = UBBR(Baud) => 12.0208
Selected Rounded UBBR = round(Selected UBBR) => 12
1 - (Selected UBBR / Selected Rounded UBBR) in percent => -0.1736%

I2C Bandwidth

I2C Bandwidth = 200000
I2C Bytes per Page = 8
I2C Page Read Overhead = 20
I2C Pages per Second = I2C Bandwidth / ((8 + 1) * I2C Bytes per Page + I2C Page Read Overhead) => 2,173.913
I2C Bytes per Second = I2C Pages per Second * I2C Bytes per Page => 17,391.3043
I2C Bytes per Frame = I2C Bytes per Second / Target Frame Rate => 579.7101
I2C Frames per Frame = (I2C Bytes per Frame in bytes) / Bytes per Frame Compressed => 5.3677

I2C TWBR Value = ((Speed / I2C Bandwidth) - 16) / 1 / 2 => 12
Speed / (16 + 2*I2C TWBR Value*1) => 200,000