Power Electronics · Analog Measurement · PCB Design

Solar-Cell Multichannel Measurement and MPPT PCB

STM32F401 solar-cell measurement mainboard and current/voltage module: power, ADC/DAC, USB/UART circuits, PCB files, and BOM.

Schematic, PCB, and BOM artifacts

⌘ Repository

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Solar-cell MPPT PCB

STM32F401 · current/voltage measurement

Schematics and BOM Design details

Problem

Driving and measuring multiple solar-cell channels requires a clear separation of shared power/reference rails, per-channel current/voltage signal chains, and MCU communication.

Architecture

12-V input → 5-V/3.3-V rails → STM32F401 mainboard → three measurement-module connectors → ADC, DAC, op amp, and current sensor → USB/UART.

Hardware and Software

STM32F401
PADS Logic
PADS Layout
INA250
AD7997
OPA703
AD5629R
USB UART

Data Flow

Cell channel → current/voltage analog path → ADC → MCU → USB/UART, with MCU setpoints → DAC → channel-control path.

Methodology

Traced the mainboard and measurement modules by connectors and nets
Decomposed power, reference, ADC, DAC, and amplifier functions into blocks
Compared the stored PADS design with a published MPPT architecture and cited its source

Results

Mapped the STM32F401 mainboard and three measurement-module connections
Identified eight-channel current/voltage measurement blocks and ADC/DAC paths
Curated design-source and BOM files for the public archive

Architecture and result views

Solar-cell schematic showing the 12-V input, 5-V and 3.3-V rails, AD7997 ADC, and measurement-module connector — Measurement-module power conversion, reference, ADC, and connector logic

Measurement-module schematic with an AD7997 ADC and eight current-signal conditioning channels — Current-sensing signal chain that collects eight channels through one ADC

Solar-cell voltage-control schematic showing the AD5629R DAC and per-channel OPA703 circuits — Voltage-control logic that distributes DAC setpoints to per-channel OPA703 paths

LM1084ISX-5.0 KTT0003B decal reconstructed from the dimensions and pad coordinates in the PADS ASCII source — KTT0003B PADS decal and pads 1–6 for the LM1084 5-V regulator

PI5A124TEX six-pin decal reconstructed from the dimensions and pad coordinates in the PADS ASCII source — SOT95P280X145-6N decal and pin-1 marker for the PI5A124 analog switch

Solar-cell BOM view listing regulators, op amps, DACs, analog switches, the MCU, and passive-component quantities — Main IC and passive-component BOM snapshot preserved in the design package

Front-side component and routing layout from the published MPPT-12 V14 reference design — Reference front layout from the published Kelzenberg, Loke, and Atwater design used for circuit analysis and comparison

Back-side copper and through-hole routing layout from the published MPPT-12 V14 reference design — Back-side copper and return-path layout of the published reference board

What I worked on

Analyzed 12-V input, 5-V/3.3-V rails, USB/UART, and SWD paths
Decomposed the INA250 current path, AD7997 ADC, OPA703 voltage path, and AD5629R DAC functions
Organized multichannel connector/net flow, BOM, and PCB artifacts

Code and results

STM32F401 mainboard and measurement-module schematic/PCB files
Parts list and PADS schematic
Architecture comparison with a published 12-channel MPPT design

Design scope and next steps

12-channel MPPT reference: Kelzenberg, Loke, and Atwater. Available artifacts: schematics, PCB files, and BOM. Follow-up measurements: accuracy, efficiency, and thermal characteristics.

Project resources

Repository

The STM32F401 mainboard records cover its 12-V input, 5-V/3.3-V rails, USB/UART, and measurement-module connectors. The module separates eight-channel current sensing, ADC, voltage amplification, and DAC paths.

Reference for the 12-channel MPPT structure: the public work by Kelzenberg, Loke, and Atwater.