PocketPD is a USB Type-C powered bench power supply that fits inside your pocket. Paired with a modern USB Type-C charger or power bank, it is a full-featured power supply that can provide a wide range of voltage with built-in safety. It is equipped with an OLED display, current sensor, and banana jack output for all your standard equipment. It also serves as a Power Delivery 3.0 profile tester.

This unique power supply leverages the Programmable Power Supply (PPS) mode that’s part of USB Power Delivery 3.0 and later versions. PPS lets you request voltage and current directly from the charger, and allows for a more compact, lightweight design. Whether you’re a pro working in the field, learning about electrical engineering for the first time, or a DIY hobbyist who demands precise power control, PocketPD is a versatile addition to your tool kit.

Bring Power With You Anywhere

Our team has extensive experience in remote sensing systems, where field troubleshooting is a common occurrence. While portable equipment has become increasingly smaller and more efficient, we’ve struggled to find a power source that offers both simplicity and flexibility. That’s why we created PocketPD: an open-source solution with a user-friendly design featuring physical buttons and a clear display. Simply plug in a compatible charger or power bank, and you’re ready to go.

The Heart is PPS

PocketPD is built around the Programmable Power Supply (PPS) mode introduced in 2015. Originally designed for improved battery charging in smartphones, PPS allows devices to set precise voltage and current levels, making it ideal for bench power supply applications. Many modern chargers and power banks, including popular brands like Anker, Ugreen, and Baseus, now support PPS. If you’re unsure whether your charger or battery pack is compatible, check its description.

Please note: PocketPD’s voltage and current output depend on your USB Type-C charger and cable. Power is limited by the lowest-rated component—for example, a 5A charger with a 3A cable will only deliver 3A. Voltage range also varies by charger, typically between 3.3V–11V or 3.3V–21V.

Power Anytime, Anywhere

The PocketPD operates from 3.3V to 21V and can negotiate up to 5A, making it compatible with a wide range of power sources—including wall chargers, power banks, and car chargers. It’s designed to unlock power wherever you are, without limitations.

A built-in magnet on the back allows easy mounting to metal surfaces, such as a crossbar on your workbench. When attached, the magnet also functions as a passive heat sink, helping to dissipate heat during extended use.

Fine-tune Power Control

With the compatible power source, you can adjust voltage in 20mV increment from 3.3V to 21V. Current limit is supported starting at 1A with 50mA steps. The selected power profile, voltage, current limit is saved in micro-controller flash memory, and retrieved at the next reboot.

Open Source

The firmware for PocketPD was developed using a combination of custom libraries and open-sourced libraries from other developers. The firmware is open-sourced and provided under an MIT license. The electronic is developed using KiCad 9.x and will be provided at a later date under a CC4.0-BY-SA license. Explore its Schematic and Firmware on GitHub. The 3D printed housing is also available for customization.

Two Versions With Different Connectors

We offer two versions of PocketPD, both of which come with pre-soldered banana jacks. The first variant also includes a detachable screw-terminal block, and the second includes two different unsoldered connectors for you to choose from: an Anderson Powerpole PP15/45 connector and an XT60 connector.

Features & Specifications

• Input: USB Type-C
• Output: 3.3 - 20 V at max 5 A
• Modes: Constant voltage (3.3 - 20 V @ 20 mV step) or constant current (1 - 5 A @ 50 mA step)
• Display: 0.96-inch OLED display
• Microcontroller: Raspberry Pi RP2040 Cortex M0+
• Protocol IC: AP33772 USB PD sink controller
• Safety Features: Short circuit, reverse current, fly-back diode protection
• Dimensions: 86 x 55 x 21 mm (3.38 x 2.16 x 0.83 in)
• Weight: 63 g (2.23 oz)

Comparisons

Support & Documentation

The firmware for PocketPD was developed using a combination of custom libraries and open-sourced libraries from other developers. The firmware is open-sourced and provided under an MIT license. The electronic is developed using KiCad 9.x and will be provided at a later date under a CC4.0-BY-SA license. Explore its Schematic and Firmware on GitHub. The 3D printed housing is also available for customization.

Manufacturing Plan

Elecrow handles the full production and assembly of each PocketPD unit. Their expertise in rapid quoting and prototype runs has significantly accelerated development through multiple iterations.

The case and knob are 3D printed using high-temperature filament, ensuring reliable performance even in hot summer conditions. We’ve also designed the packaging with sustainability in mind—reducing landfill waste while maintaining robust protection, all without relying on excess foam. Before shipping, every unit undergoes thorough functionality testing to ensure quality and reliability.

Fulfillment & Logistics

After our production run is complete, we will package everything up and send it along to Crowd Supply’s fulfillment partner, Mouser Electronics, who will handle distribution to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.

Risks & Challenges

This project has undergone several design iterations over the years to ensure both durability and reliability. The core functionality has remained stable for some time, and we’re gradually introducing firmware updates that offer enhanced control over power settings. As a result, we’re confident that the device is robust, well-tested, and ready for broader use.

Following a thorough supplier evaluation and a successful pre-production run, we’ve built a solid bill of materials that allows flexibility in case any components become unavailable. While every project carries some level of risk, we’ve taken proactive steps to minimize disruptions and ensure smooth, on-time delivery.