[Verified] EV2400-Lite based on MSP430F5529

Project Introduction:
          The EV2400 is an official debugger from TI, designed to replace the EV2300 for BQ series battery chargers, fuel gauges, and battery protection chips. These chips can communicate with the EV2400 via I2C/SMB/DQ buses. The EV2400, in conjunction with the BQStudio host software, completes the basic chip settings before the chip can be used normally. Therefore, the EV2400 is an indispensable tool for BQ series chip development.
          DJI drones and some laptop batteries from various manufacturers also use BQ series fuel gauges for battery protection and power monitoring; however, under certain circumstances, such as prolonged dust accumulation, accidental short circuits, or replacement of battery cells, the fuel gauge may detect undervoltage/overcurrent/open circuit in the battery pack, causing the battery pack to lock up and become unusable. To restore normal operation in this case, besides going to after-sales service, it is necessary to use the EV2400 to reconfigure the relevant registers of the fuel gauge and unlock the battery pack.
          Since the official price of TI's EV2400 is prohibitively high (price as of writing, as shown in the image)
          , fortunately, TI has released the schematic diagram for the EV2400, allowing us to purchase a relatively inexpensive one on Taobao/Xianyu. Alternatively, if you don't want to be ripped off or enjoy tinkering, building your own is a good option. This project provides a verified, well-protected, cost-effective, and aesthetically pleasing DIY EV2400 solution.
Construction Process:
1. Schematic Diagram Drawing:
          TI has released the schematic diagram for the EV2400, which mainly includes three parts: data conversion, level conversion & interface protection, and level setting. In TI's official solution, the MSP430F5529 microcontroller is used as the data conversion microcontroller, currently priced around 25 RMB on Taobao, which is acceptable and represents the majority of the cost of this debugger. (The image shows a 5529 chip from Taobao for 23 yuan.)
(Note: Some people online have also found that the F5528 (average price around 10 yuan) can be used as a substitute, and there are related solutions. However, I have verified this myself. I bought four chips from different stores, and they either didn't have the core voltage, the crystal oscillator didn't oscillate, or they could only be flashed but couldn't run. There were too many bad products. I spent 40 or 50 yuan on chips but didn't get a single usable one. It's better to just go for the 5529; at least genuine ones are easier to find.) (I'm begging for a reliable source so I can finally put a perfect end to this board that I've been working on for two weeks.)
24/9/20: The 5528 version is now complete and open source. Open source address: [Verified] EV2400-Lite based on F5528 [Not recommended for replication] -
It's important to note that using the LCSC open-source hardware platform (oshwhub.com) with the 5528 is not recommended due to the high cost of genuine products and the prevalence of refurbished and
          substandard chips in the market. The reasons are explained in the open-source link. TI's official solution uses an adjustable linear regulator in conjunction with a Renesas digital potentiometer to achieve an adjustable reference level. As is well known, these are less common chips, and those sold on Taobao or other reputable platforms are unreliable, while those available here are expensive. Therefore, the adjustable voltage reference level is omitted, leaving only a reference level input pin. Users can short this pin with a jumper cap to determine the communication reference level.
(However, it's worth noting that some sources I consulted (unofficial sources) stated that non-adjustable reference levels (such as the fixed 3.3V reference level used in most lightweight EV2400s on the market) might damage the chip being debugged. However, in my humble opinion, TI, as one of the world's leading analog chip design and manufacturing companies, would certainly consider various application environments. Furthermore, the internal block diagrams provided by TI (using the BQ4050 as an early representative) show that the chip's data interface uses a logic gate buffer circuit between the internal CPU (as shown in the figure).
In many designs, the MCU with a 3.3V reference level communicates directly with the battery protection chip, and I haven't seen any chip damage reported. Moreover, in section 6.3 of the BQ4050 datasheet, the maximum withstand voltage for the SMC and SMD interfaces is 26V (as shown in the figure).
Meanwhile, another TI... ) The BQ40Z80 battery fuel gauge and protection chip integrates a lightweight EV2400 on its EVM. The official schematic indicates that no level conversion IC is used between its interface and the fuel gauge IC interface; instead, only a few pull-up and pull-down resistors are used (as shown in the figure). Research indicates that the BQ40Z80's internal CPU also uses a 1.8V power supply, suggesting that it has internal level conversion circuitry. (Personally, I believe a 3.3V logic level is perfectly acceptable.) While
          other aspects can be simplified, protection is a crucial function for debuggers. Especially for debuggers that may deal with several or even a dozen battery packs, incorrect connections can cause sparks and damage, potentially even to the computer. Therefore, protection is essential. This solution includes ESD and overcurrent protection. I used a one-time fuse, but it could be replaced with a PTC resettable fuse for even better performance.
2. PCB Design:
           The same board type as the previous ST-LINK was used, so the outer shell file only needed minor modifications to be usable (actually, it's just laziness []~(￣▽￣)~* (slacking off,
so satisfying!)). The direct-output design means the USB socket, debugger, and debug cable form a straight line, taking up less space. (If you're interested in that ST-Link, here's the link.) ((As an aside, while browsing the MSP manual recently, I found some tutorials from TI on porting STM chip programs to MSP series microcontrollers—stealing ST's talent, haha!) It's true that red and blue are a perfect match! ヾ(≧▽≦*)o)
Since the 3.3V power supply is mainly used as a reference level this time, an LDO was used instead of a DC-DC converter to provide 3.3V.
3. Soldering & Debugging & Assembly:
          There's not much to say about this. Component selection and soldering are basic skills. Anyone who uses this equipment should be proficient in these areas, so I won't presume to teach you. (Here are two pictures of the soldered components:)
However, I still need to mention a few things about component purchases:

MSP430F5529IPNR purchase link: MSP430F5529
level conversion chip purchase link: RS0102YH8
protection diode array: TPD4E05U06DQAR

The above components are just my purchase channels, provided for your DIY convenience only. I do not guarantee the lowest price links, and only indicate that the components were usable at the time of my purchase. This is not an advertisement.
 
Debugging – Firmware Download (Important!!!)
        If the chip you receive is new, it will not have any internal program. If it is a salvaged chip, it will have unnecessary program. You can't just buy an eZ-FET to download the program just to build an EV2400, right? No worries, TI provides an even more convenient method – downloading via the MSP430F5529's USB-BSL mode.
        In simple terms, this mode is equivalent to redefining the pins used for SWD in STM32. To download a program again, you can only do so by setting the microcontroller to UART download mode during a reset using the high and low levels of BOOT1 and BOOT0, and then burning the program through the UART1 port. The MSP430F5529 will detect the level of the USB-PUR pin during a reset. If it is pulled high, it enters USB-BSL mode, reports itself as a USB device, and reports its specific VID and PID. The host software detects the presence of the microcontroller by detecting the VID and PID and performs a full erase and write of the new program to the microcontroller via USB. With
        the theoretical analysis complete, here are the practical steps:

First, download the EV2400 updater from the TI website (currently the latest version is 0.32), or you can download it from the firmware section at the end of this article. After downloading, as shown in the image: Right-click and select "Run as administrator." After installation, a "TI" folder will appear on your C drive. Locate the folder named "EV2400Updater-0.32" inside. The first file in the folder contains our programming program . However, if you directly open it, you'll find that it says it doesn't find the EV2400. This is normal; our EV2400 hasn't been programmed yet. We need to pass parameters to this program so it knows to program a chip that doesn't have a program yet. Right-click the program, select "Create Shortcut," then right-click the created shortcut, click "Properties," type a space after "Target," and then enter "-s." Click " Apply" and then "OK." Now, plug your soldered EV2400 into the computer. Use tweezers to short-circuit the two shorting points shown in the diagram (the two ends of silkscreen R6). Then, and this is crucial: while maintaining the short circuit, press the reset button. Release the reset button and immediately remove the tweezers. You should hear a device connection beep on the computer, but no new device will appear in Device Manager, indicating that the computer has recognized the chip. Double-click the shortcut you just created. The software should then indicate that it is erasing, and the computer should emit a device pop-up beep. After the software finishes running, re-plug the chip or press the reset button. The computer should emit another device insertion beep, and all three blue LEDs should light up, indicating that the programming is complete. (Note: If you short-circuit the tweezers to R6 for an extended period, the computer will also emit a device insertion beep and display an unknown device message. This is normal and can be ignored; simply start the process from the beginning. It is not a hardware or chip issue.)
Next, download the BQStudio installation software from the official website or the attached file. After installation, insert the EV2400 with the software pre-programmed. Open BQStudio. It will ask you to select the target chip to debug; choose any one. Once inside, the top left corner will display the currently connected debugger and its software version, as shown in the image. OK, the EV2400-Lite setup is now complete. Go ahead and enjoy unlocking the battery OR the grueling debugging!

Shell Assembly:
        If you don't want your debugger to be exposed, usable shell files are provided in the attachment. It is recommended to use an FDM 3D printer with a 0.2mm nozzle (0.4mm is also acceptable). Use a soldering iron to insert an M2 thermoforming nut with an outer diameter of 3mm and a height of 3mm, and use it with an M2_8mm countersunk screw. For specific instructions, please search for "3D printing thermoforming nut". I won't go into details here. A diagram is also included. Find a print shop and have them print the diagram at a size of 32*52mm (note the units!!!), then attach it to the top cover. That's it!
(This light is so bright, haha. A larger current-limiting resistor or a black casing for printing would probably be better.)
(The image is slightly smaller because I told the seller a specific size, but she still chose automatic scaling to fit. (Laughs, if you can scale it however you want, guess why I told you a fixed size?))
Regarding the attachments:
          The attachments are software related to the EV2400, as well as some unlocking passwords and techniques, collected from the internet and offered free of charge. Accuracy is not guaranteed; you'll need to try them yourself. (Updated periodically). Don't forget to bookmark or give it a free like! (。・∀・)ノ
Due to the large size of some software files, LCSC couldn't upload them, so I had to use Baidu:
Link: https://pan.baidu.com/s/12k6vG-GeNx7NKa42GbXFbw?pwd=6699 Extraction code: 6699
 
Update log:
2024/8/11 - Thanks to @WOLZG for pointing out the reversed silkscreen issue; it has been corrected.