electronics manufacturing

Where is the ADC? RIGOL DM858 Teardown | Voltlog #486

Ever wondered what lies beneath the sleek exterior of the high-tech Rigol DM858 multimeter? In a recent teardown video, we took a deep dive into the inner workings of this precision instrument, uncovering the components that make it tick. Right off the bat, the teardown revealed the beautiful construction and assembly quality, with key areas like power supplies, connectivity, and a clever system-on-module design.

The power supply section was straightforward, with a USB-C input and a series of switchers to step down the voltage to the required levels. The real star of the show was the SODIMM module, housing an Allwinner A40i-H quad-core Cortex-A7 processor, RAM chips, flash memory, and a power management circuit.

This modular design offers several advantages, including cost savings, flexibility, and the ability to swap out components as needed. Moving on to the input section, we encountered a curious square PCB module housing the user-accessible fuse and input protection components like gas discharge tubes, Metal Oxide Varistors, and clamping devices.

Underneath a small shield, we found relays likely responsible for input switching and range selection. One of the most intriguing discoveries was the potential use of the microcontroller’s built-in ADC (Analog-to-Digital Converter) instead of a dedicated ADC chip. This design choice, if true, would be a clever solution for high sampling rates and accurate measurements.

However, not all mysteries were solved. We encountered a few unidentified components, leaving us scratching our heads. Can you help shed light on these enigmatic parts? Leave a comment below and join the discussion!

Designing An Automated PCB Test System | Voltlog #475

In this captivating project, Voltlog takes us on a journey to revolutionize the testing and programming process for their VoltLink boards. Tired of the repetitive and time-consuming manual approach, they set out to design a semi-automated test and programming fixture called VoltHub7. The VoltLink, a reliable USB-to-Serial adapter designed to solve the inconsistencies of cheap alternatives, is a crucial component in Voltlog’s electronics design work.

However, manually testing and flashing each board one by one proved tedious and error-prone, leading to the need for an automated solution. Enter the VoltHub7, a ingenious system that combines a custom-designed USB hub and a Raspberry Pi Zero 2W. At the heart of the design lies the Microchip USB2517, a configurable 7-port USB 2.0 Hi-Speed hub controller, carefully chosen for its capabilities and minimal external circuitry requirements.

Voltlog meticulously crafted the USB hub PCB, incorporating features like power distribution switches, status LEDs, and multiple power input options for flexibility. The integration of the Raspberry Pi Zero 2W directly onto the PCB, with its GPIO interfacing with the hub controller, streamlines the setup and enhances reliability.

But the true innovation lies in the use of pogo pins to interface with the Pi Zero’s test pads, eliminating the need for fiddly micro-USB cables and ensuring a robust connection. Voltlog’s attention to detail in the mechanical design, ensuring precise component alignment and fit, is a testament to their commitment to excellence.

The assembly process, complete with a black soldermask and yellow silkscreen for a visually striking result, culminated in a successful power-on and initialization of the hub and Pi Zero. Voltlog’s joy at witnessing the seamless integration of the components is palpable, inviting viewers to share in their excitement.

With the VoltHub7 up and running, Voltlog demonstrated its capability to connect and flash six VoltLink boards simultaneously, a task that would have been significantly more time-consuming with manual intervention. The future holds the promise of a custom test jig, further streamlining the process and eliminating the need for individual USB cables.

Tag-Connect To ST-Link or J-Link Adapter PCB | Voltlog #460

In the ever-evolving world of electronics engineering, efficient and cost-effective solutions are always in high demand. One such innovation that has gained traction is the Tag-Connect JTAG connector, a game-changing alternative to traditional connectors. These pogo pin-style connectors offer a standardized form factor, making them a versatile choice for a wide range of PCB designs.

Tag-Connect connectors boast several advantages over their traditional counterparts. Firstly, their compact size saves valuable PCB real estate, allowing for higher component density and more efficient layout. Secondly, their simplicity eliminates the need for additional components, reducing overall manufacturing costs.

Furthermore, their durability and ease of use make them an ideal choice for both manual and automated production lines, streamlining the manufacturing process and minimizing labor costs. One of the challenges faced by electronics enthusiasts and professionals alike is interfacing Tag-Connect connectors with programming tools like ST-Link or J-Link, which often have different connector types.

To address this issue, a custom adapter PCB was designed, bridging the gap between these connectors and ensuring seamless integration. This adapter PCB not only solves compatibility issues but also showcases the versatility of Tag-Connect connectors. By incorporating footprints for various connector types, such as the 10-pin Tag-Connect model and a VoltLink connector, the adapter PCB becomes a versatile debugging interface, capable of supporting UART, GPIOs, and even flashing ESP32 modules through a Tag-Connect wire.

The design process of the adapter PCB highlights the importance of careful footprint selection and the ability to adapt to unforeseen challenges. Even when a footprint error occurred, the modular nature of the design allowed for a workaround, ensuring the PCB’s usability and demonstrating the resilience of the electronics engineering community.