Powering a Zepp Golf Tracker - Page 1
Forum section: electronics / repair

author: tja
author_rank: Contributor
timestamp: May 19, 2015, 06:04:32 pm
content: Hi All,I recently acquired a Zepp Golf tracking device on eBay.The battery is missing, and as you can see from the photos it is in a rather poor state. Before I write it off as an eBay mistake and chuck it in the bin, I thought I would at least power it up. What am not sure about and could do with some advice on is what voltage to use, and where to connect. The obvious thing to do is connect 5v across 5v & Gnd, but then I wondered if that is just for the USB charging? Can you actually get any LiPo (or LiOn or whatever) batteries that are 5v anyway? Maybe 3.7v across Vbat & Gnd would be a better bet?Any advice gratefully received.CheersTim

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 20, 2015, 12:17:32 am
content: Njaaah. The dirty bastids put the SMT module on top of the power vias.*shakes the proverbial fist at the proverial whatever*Second picture, top right chip: Find a datasheet or post a number/more clear picture for better advice.Apples for oranges, though, I'm going to bet that you're either spot on or next to it about that being a charge regulator operating off of a 5V supply.This 5V may also be able to power the device without the balancing properties of a luggy capacitance, such as is a Lithium Polymer cell.When trying to rebuild it, be very aware that often in simple or small devices the empty-battery maximum charge current is left to the power supply, so start carefully.Once it becomes a "seriously nobody knows" a first step would be conservatively set a lab supply, say 50 or 100mA at either 3V or 5V, depending on what you're "emulating".Applying a short burst (< 5s) of maximum 250mW to something not expecting that voltage has a chance of not causing permanent damage, where longer exposure or higher currents often make things, chips especially, go *pop* quite efficiently and permanently. Fun as it may be, you might want to save that little giggle for when you want rid of it.Important disclaimer: I do say "has a chance of not causing damage". Because it also still has a chance, though maybe not high, to go *poof* anyway and I am very unwilling to accept any blame in such cases.I specify 3V for Vbat, in case you are not sure about the battery used, 3V covers most common set-ups post 2000. It falls within the operational voltage of LiIon/LiPoly (2.7V to 4.2V), LithiumPrime CR2032 types (2.2V to 3.2V), LiFePO4 (2.2V to 3.6V) and double alkaline (1.8V to 3.4V).

author: tja
author_rank: Contributor
timestamp: May 21, 2015, 10:22:04 am
content: Thanks for the response!Chips in the top row, left to right, are:STmicroelectronics 32f103d6, which may be a STM32F103RDY6TR - datasheet availableMarkings 2403 33hh XCLB0 - unidentified - any ideas?STmicroelectronics 3ga51h Gyroscope - a new and funky device, no data sheet available

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 21, 2015, 10:47:49 am
content: No worries.Here to help if I can :-)The middle one seems like it might be a charge controller/limiter, since it isn't the right one. I will have a look later today, when I need a break (or when my current Dave playlist ends ;-) ).Could you create a sharper/higher res image of the top half on both sides?Feel free to send them to me directly if online-ing them is hard due to size or whatever.

author: tja
author_rank: Contributor
timestamp: May 21, 2015, 11:58:25 am
content: I'll see what I can do tonight. Ihavesome high res photos, but finding it incredibly difficult to get a single shot where the markings ofallthe IC's are visible - I suspect a composite may be the way to go ..

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 21, 2015, 12:14:45 pm
content: The keys for me are:1. Seeing the markings on the chip you couldn't identify, also for directionality, but maybe the orientation of the markings rings a bell that the text itself doesn't.2. Seeing what's connected to what, outside of the little SMT plate (annoying thing) to get some context out of the wiring.Dollars for donuts, though, connecting a LiIon chemistry type cell and pushing in 100mA at 5V would probably work and you'll see the 5V drop to 3.x to 4.3V at first and then when the battery is deemed full it'll jump back to 5V and hardly any consumption of current (only the few mA needed for the electronics).I do have to say, in that, that it's a decent guess, not a promise. Nor do I have or want any donuts or dollars.

author: tja
author_rank: Contributor
timestamp: May 21, 2015, 08:38:39 pm
content: Hi-res as requested. If it looks slightly odd, it is because it is a composite, due to the afore mentioned lighting problem :-)

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 21, 2015, 09:07:15 pm
content: Very good job.The grouping of the caps and the copper layout around the middle one do point to some sort of power path.The print on the chip seems to includeXCL (small:) BQOn the bottom line and 2403 on the top line. A common (annoying) practice is to negatively wrap around the letters to the last line. I never researched what the reasons for that are, I just noticed it.So as a last confirming effort I searched BQ2403.Which turns out to be a TI series of powerpaths with different pin count. Though they seem nearly compatible in function and components to what I see happening on the board here.Unfortunately TI only has them BQ24030, 24031, 24032 and 24034 as far as I can quickly (and somewhat lazily) see.So I then googled BQ24033 (on account of the extra 3's in there) and turns out in Hong Kong they do know that number and from the bits and bobs I manage to comprehend, that too is a power path, but I couldn't figure out the pin count, pinout or voltages to account for.All in all, the chip is likely to be an active 5V -> 4.2V converter and power manager for 5V or Bat power to the rest of the unit.Here the da'da'sheet of the TI series, which unfortunately is rectangular and slightly more... pinned... than the chip on your board:http://www.ti.com/lit/ds/symlink/bq24032a.pdfEDIT: So it just became a smidge more likely that you can hook up a ~250mAh to ~1000mAh single LiPoly, for example from miniature RC helicopter fame, and hook up a healthy 5V supply to get it charged.

author: tja
author_rank: Contributor
timestamp: May 21, 2015, 10:09:35 pm
content: Excellent! Thanks for your efforts. What do you think I connect it to - Gnd & Vbat ?Thanks again for your help.

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 22, 2015, 12:00:34 am
content: Battery most likely as you say between Vbat and GND, the charge-adaptor/supply between GND and 5V.Whether that other connection says "Vido" of "Vldo" isn't fully clear to me; however I might suspect Vldo for low-drop-out voltage.It could also be a thermistor input to monitor the battery temp, but then Vido would be a very weird name for a thermistor.Usually they're more "Craig" and "Jim" type things.