@@ -121,7 +121,7 @@ One easy way to get power to your project is through USB. It can deliver up to 1
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@@ -121,7 +121,7 @@ One easy way to get power to your project is through USB. It can deliver up to 1
- Add a ”USBOTG” connector to your schematic. Already here you can think about how you should connect your mouse and use a suitable connector (mini, micro or even usb-c).
- Add a ”USBOTG” connector to your schematic. Already here you can think about how you should connect your mouse and use a suitable connector (mini, micro or even usb-c).
- Find the USB pinout for your connector.
- Find the USB pinout for your connector.
### 9) 3.3v Power Supply
### 9) 3.3V Power Supply
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.
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.
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@@ -143,13 +143,11 @@ For some components (like the PMW3389DM-T3QU) there might not exist a pre-made l
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@@ -143,13 +143,11 @@ For some components (like the PMW3389DM-T3QU) there might not exist a pre-made l
Hint. Never, never ever, change the grid settings when placing the pins in the symbol.
Hint. Never, never ever, change the grid settings when placing the pins in the symbol.
### 11) 1.9v Power Supply
### 11) 1.9V Power Supply
As you can see in the PWM3389DM-T3QU datasheet and reference schematics, the sensor requires a 1.9v power supply. This is a much less common voltage for a fixed output LDO (try finding one from Elfa or rs-online and you will likely fail).
As you can see in the PWM3389DM-T3QU datasheet and reference schematics, the sensor requires a 1.9v power supply. This is a much less common voltage for a fixed output LDO (try finding one from Elfa or rs-online and you will likely fail).
To that end, you can use an adjustable voltage regulator, such as [MIC5235YM5-TR](https://www.elfa.se/en/ldo-voltage-regulator-24-20v-sot-23-microchip-mic5235ym5-tr/p/30099685), which will let you set your desired output voltage using external resistors.
To that end, you can use an adjustable voltage regulator, such as [MIC5235YM5-TR](https://www.elfa.se/en/ldo-voltage-regulator-24-20v-sot-23-microchip-mic5235ym5-tr/p/30099685), which will let you set your desired output voltage using external resistors. The circuit and equation for calculating the resistor values needed to acheive the desired the output voltage (1.9V) can be found in the [datasheet](https://www.elfa.se/Web/Downloads/_t/ds/MIC5235YM5-TR_eng_tds.pdf) for the regulator. Here you will also find information about input- and output capacitor values needed for proper operation.
The circuit and equation for calculating the resistor values needed to acheive the desired the output voltage (1.9V) can be found in the [datasheet](https://www.elfa.se/Web/Downloads/_t/ds/MIC5235YM5-TR_eng_tds.pdf) for the regulator. Here you will also find information about input- and output capacitor values needed for proper operation.
Once you have added the 1.9v power supply you can add a new power net, and connect that to your PMW3389 component.
Once you have added the 1.9v power supply you can add a new power net, and connect that to your PMW3389 component.
