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#Goal

- Integrate an SMD ATtiny85 microcontroller (preferably ATTINY85-20SU) in the existing ModuloATtiny85 / Gay Teal P.K.E. Meter project. The new MCU will use the SYS rail (from the MP2650 charger) for power, have its ground connected to the main GND, utilize a 100 nF decoupling capacitor between VCC and GND, and provide production programming access via designated pins.

#Implementation plan

1. Add and configure the ATtiny85 MCU

1. Select and add the SMD ATTINY85-20SU to the schematic.

2. Connect the VCC pin of the ATtiny85 to the SYS power rail from the MP2650 charger section.

3. Connect the GND pin of the ATtiny85 to the main GND net.

2. Add power decoupling

1. Place a 100 nF decoupling capacitor between the VCC and GND pins of the ATtiny85.

3. Provide manufacturing programming access

1. Identify and expose production test points for the following pins:

1. PB0 (MOSI)

2. PB1 (MISO)

3. PB2 (SCK)

4. PB5 (RESET)

2. Label these testpoints appropriately for pogo-pin ICSP access.

4. Review the schematic changes

1. Verify all power connections and decoupling components are correctly connected.

2. Ensure test points are accessible and clearly marked for production programming.

#Success criteria

- Successfully integrated the ATtiny85 with proper SYS power and GND connections.

- Installed a 100 nF decoupling capacitor between VCC and GND of the MCU.

- Exposed and labeled PB0, PB1, PB2, and PB5 as production programming test points for pogo-pin ICSP access.

Set System Architecture to "```mermaid flowchart TD USB[USB-C Input] --> CHG[MP2650 Charger Power Path] BAT[LiIon Battery] --> CHG CHG --> SY..."

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