Beware of Flashless ESP32-C3 Mini Boards
▼ Summary
– ESP32-C3 Super Mini boards are popular but difficult to purchase reliably because they come with different, unspecified variants of the ESP32-C3 chip.
– The most problematic variant is the basic ESP32-C3 without markings, as it lacks built-in Flash memory for program storage.
– According to the datasheet, only the FH4 and FH4X chip variants are currently viable, with the FH4X being the newest and recommended version.
– Identifying the exact chip variant from online listings is challenging, as it requires clear photos of the small markings on the chip itself.
– If you accidentally receive a Flash-less variant, you can add an external Flash chip, but this is not the intended or convenient use case.
When shopping for compact microcontroller boards, the ESP32-C3 Super Mini presents a popular option, but buyers must exercise caution to avoid a significant pitfall. These boards are often sold with different underlying chip variants, and purchasing the wrong one can lead to a frustrating experience. The core issue lies in a specific version of the ESP32-C3 chip that lacks any internal Flash memory, rendering it unable to store a program without additional components.
The problem is clearly outlined in official documentation. Espressif’s datasheet for the ESP32-C3 lists several chip models. The version marked simply as “ESP32-C3” with no additional letters is the one without built-in Flash. Other variants include designations like FN4, FH4, FH4AZ, and FH4X. Here, the first letter ‘F’ confirms the presence of internal Flash memory. The following letter indicates the chip’s temperature rating, with ‘H’ denoting a high-temperature range. The number specifies the Flash capacity in megabytes, which is typically 4MB for these models. Notably, the FN4 is listed as End-of-Life, and the FH4AZ is Not Recommended for New Designs, leaving the FH4 and the newer, recommended FH4X as the primary choices for most projects.
For consumers, identifying which chip is on a board before purchase is notoriously difficult. The information is printed in a tiny, third-row marking on the chip itself, as shown in product photos. However, relying on often blurry or absent images in online listings is a risky strategy. Sellers frequently do not specify the exact chip variant, leading to accidental purchases of the Flash-less model. If you do receive a board with the bare ESP32-C3 chip, all is not lost. It is technically possible to solder an external Flash memory chip to the board, but this requires advanced soldering skills and additional components, defeating the purpose of buying a convenient, pre-assembled mini board.
The situation serves as a critical reminder for anyone buying electronic components online. Always verify the exact chip model when possible, and purchase from reputable sellers who provide clear, detailed specifications. For a smooth development experience, specifically seek out boards confirmed to use the ESP32-C3FH4 or FH4X chips to ensure your project has the necessary built-in storage from the start.
(Source: Hackaday)