Macrofab Engineering Podcast

MEP EP#338: Feature Complete or Minimal Viable ProductsProject DiffProbe Landed on the topology Stephen wants High voltage dividers Compensation capacitors CMRR calibration (120dB rejection) Offset correction Buffers and Instrumentation Amplifiers Differential Stage 10x and 100x attenuation means offsets have to be bang on Opamps (3 of them) Buffers Low input bias current Low offset Bandwidth? Differential amp Low offset. Capable of driving 50 ohm load to the scope Gain setting resistors Vishay ACAS 0612 - Precision resistor network 4x0603 resistors to make a diff amplifier with a gain of 2 Relative tolerance of 0.05% Worst case relative temp-coefficient 15ppm Project Snackey Firmware is “feature complete” Display Commands How the vending motors actually work INA219 Current Sensor Interrupts Improved method for next revision? The one byte Serial Buffer problem NEOPIXEL (WS2812) vs APA102 (SK9822) Blocking functions DMA - Direct memory access Im