Eval¶

CANDis is quite silent.

CANBuz probably will have same issues. Need to test capacitors.
F=As/V
qalc 0,000022*3 = 0,000066 = 0,066mAs
Ich hab doch noch grosse
Is it the power regulator/LDO? What did i solder?

Parts¶

• LM386; DS ; page 10
• LM4861 M; 1,39€
  • can be driven @5V; not sure if V+ has to be 3v/2 or 5v/2 ?
  • Shutdown: power output off on logic high

Amp¶

lm4871

MCU¶

• STM32F042G4U6; UFQFPN28; 16KB; hab ich noch 17
• Get rid of an STM32F072 in order to have DAC?
• STM32G431KBU6
  • SAI; FPU
  • 5,87€
• STM32F072CBT6
  • LQFP-48
  • 2,40 €
• STM32F103CBT6
  • 2,12 €
• STM32F303C6U6A

DAC¶

• Maybe later; SAI would be more interesting. DAC for testing DMA.
• 44,100 Hz
• Would require SPI flash for recorded sound
• Adjustable volume
• Solderbridge for fallback

Flash¶

DAC-DMA already works for sinewave (copied due to speed). So FLash might be cool for sound samples.
CD: 44100 samples / sec;
44100*2*2 = 176'400 Bytes / s;

1MB would play around 6 seconds. 2MB / 16Mbit would be ok.
32Mb/4MB available for 1,94€; 100Mhz
STM32F303 has max SPI rate 18Mbits/s

USB¶

USB would be nice for writing sound samples to flash. But this might be a nice candidate for writing flash images over CAN.
Although it might take very long time.