diff --git a/README.md b/README.md index 63607261bd4a5ad8ca34b4c6dc02bea32fdb2322..d31070b975590a4d9e9a795a687c0b12ce2db6b9 100644 --- a/README.md +++ b/README.md @@ -96,7 +96,7 @@ The crystal will resonate at a specified frequency. Its waveform will be used as - Find the device/Crystal. - Place it close to `PH0` and `PH1`, pin 5 and 6 (`RCC_OS_CIN` and `RCC_OSC_OUT`). - Connect the component with wires to the mentioned pins. Value 12MHz. -- Connect one 22p capacitor to each pin on the crystal and connect the other end of the capacitors to GND. +- Connect one 22pF capacitor to each pin on the crystal and connect the other end of the capacitors to GND. ### 7) Serial Wire Debug (SWD) connector @@ -117,7 +117,7 @@ One easy way to get power to your project is through USB. It can deliver up to 1 ### 9) 3.3v Power Supply -The MCU needs a stable voltage. A common for digital components is 3.3v. To this end we will use a fixed LDO (low dropout) regulator, with a 5v input (powered from the USB connector) and 3.3v output. We will use the [AP2125N-3.3TRG1](https://www.elfa.se/en/ldo-voltage-regulator-3v-360ma-sot-23-diodes-incorporated-ap2125n-3trg1/p/30041163) +The MCU wants to be powered from a 3.3V rail. To this end we will use a fixed LDO (low dropout) linear regulator, to convert a 5V input (from the USB connector) to a 3.3V output. We will use the [AP2125N-3.3TRG1](https://www.elfa.se/en/ldo-voltage-regulator-3v-360ma-sot-23-diodes-incorporated-ap2125n-3trg1/p/30041163) for this. Look in the [datasheet](https://www.elfa.se/Web/Downloads/_t/ds/AP2125_eng_tds.pdf) for a typical application circuit. Later we will design the power supply for the PWM3389 sensor, which is a bit trickier.